Python History -------------- This file contains the release messages for previous Python releases. As you read on you go back to the dark ages of Python's history. ====================================================================== What's New in Python 2.4 final? =============================== *Release date: 30-NOV-2004* Core and builtins ----------------- - Bug 875692: Improve signal handling, especially when using threads, by forcing an early re-execution of PyEval_EvalFrame() "periodic" code when things_to_do is not cleared by Py_MakePendingCalls(). What's New in Python 2.4 (release candidate 1) ============================================== *Release date: 18-NOV-2004* Core and builtins ----------------- - Bug 1061968: Fixes in 2.4a3 to address thread bug 1010677 reintroduced the years-old thread shutdown race bug 225673. Numeric history lesson aside, all bugs in all three reports are fixed now. Library ------- - Bug 1052242: If exceptions are raised by an atexit handler function an attempt is made to execute the remaining handlers. The last exception raised is re-raised. - ``doctest``'s new support for adding ``pdb.set_trace()`` calls to doctests was broken in a dramatic but shallow way. Fixed. - Bug 1065388: ``calendar``'s ``day_name``, ``day_abbr``, ``month_name``, and ``month_abbr`` attributes emulate sequences of locale-correct spellings of month and day names. Because the locale can change at any time, the correct spelling is recomputed whenever one of these is indexed. In the worst case, the index may be a slice object, so these recomputed every day or month name each time they were indexed. This is much slower than necessary in the usual case, when the index is just an integer. In that case, only the single spelling needed is recomputed now; and, when the index is a slice object, only the spellings needed by the slice are recomputed now. - Patch 1061679: Added ``__all__`` to pickletools.py. Build ----- - Bug 1034277 / Patch 1035255: Remove compilation of core against CoreServices and CoreFoundation on OS X. Involved removing PyMac_GetAppletScriptFile() which has no known users. Thanks Bob Ippolito. C API ----- - The PyRange_New() function is deprecated. What's New in Python 2.4 beta 2? ================================ *Release date: 03-NOV-2004* License ------- The Python Software Foundation changed the license under which Python is released, to remove Python version numbers. There were no other changes to the license. So, for example, wherever the license for Python 2.3 said "Python 2.3", the new license says "Python". The intent is to make it possible to refer to the PSF license in a more durable way. For example, some people say they're confused by that the Open Source Initiative's entry for the Python Software Foundation License:: http://www.opensource.org/licenses/PythonSoftFoundation.php says "Python 2.1.1" all over it, wondering whether it applies only to Python 2.1.1. The official name of the new license is the Python Software Foundation License Version 2. Core and builtins ----------------- - Bug #1055820 Cyclic garbage collection was not protecting against that calling a live weakref to a piece of cyclic trash could resurrect an insane mutation of the trash if any Python code ran during gc (via running a dead object's __del__ method, running another callback on a weakref to a dead object, or via any Python code run in any other thread that managed to obtain the GIL while a __del__ or callback was running in the thread doing gc). The most likely symptom was "impossible" ``AttributeError`` exceptions, appearing seemingly at random, on weakly referenced objects. The cure was to clear all weakrefs to unreachable objects before allowing any callbacks to run. - Bug #1054139 _PyString_Resize() now invalidates its cached hash value. Extension Modules ----------------- - Bug #1048870: the compiler now generates distinct code objects for functions with identical bodies. This was producing confusing traceback messages which pointed to the function where the code object was first defined rather than the function being executed. Library ------- - Patch #1056967 changes the semantics of Template.safe_substitute() so that no ValueError is raised on an 'invalid' match group. Now the delimiter is returned. - Bug #1052503 pdb.runcall() was not passing along keyword arguments. - Bug #902037: XML.sax.saxutils.prepare_input_source() now combines relative paths with a base path before checking os.path.isfile(). - The whichdb module can now be run from the command line. - Bug #1045381: time.strptime() can now infer the date using %U or %W (week of the year) when the day of the week and year are also specified. - Bug #1048816: fix bug in Ctrl-K at start of line in curses.textpad.Textbox - Bug #1017553: fix bug in tarfile.filemode() - Patch #737473: fix bug that old source code is shown in tracebacks even if the source code is updated and reloaded. Build ----- - Patch #1044395: --enable-shared is allowed in FreeBSD also. What's New in Python 2.4 beta 1? ================================ *Release date: 15-OCT-2004* Core and builtins ----------------- - Patch #975056: Restartable signals were not correctly disabled on BSD systems. Consistently use PyOS_setsig() instead of signal(). - The internal portable implementation of thread-local storage (TLS), used by the ``PyGILState_Ensure()``/``PyGILState_Release()`` API, was not thread-correct. This could lead to a variety of problems, up to and including segfaults. See bug 1041645 for an example. - Added a command line option, -m module, which searches sys.path for the module and then runs it. (Contributed by Nick Coghlan.) - The bytecode optimizer now folds tuples of constants into a single constant. - SF bug #513866: Float/long comparison anomaly. Prior to 2.4b1, when an integer was compared to a float, the integer was coerced to a float. That could yield spurious overflow errors (if the integer was very large), and to anomalies such as ``long(1e200)+1 == 1e200 == long(1e200)-1``. Coercion to float is no longer performed, and cases like ``long(1e200)-1 < 1e200``, ``long(1e200)+1 > 1e200`` and ``(1 << 20000) > 1e200`` are computed correctly now. Extension modules ----------------- - ``collections.deque`` objects didn't play quite right with garbage collection, which could lead to a segfault in a release build, or an assert failure in a debug build. Also, added overflow checks, better detection of mutation during iteration, and shielded deque comparisons from unusual subclass overrides of the __iter__() method. Library ------- - Patch 1046644: distutils build_ext grew two new options - --swig for specifying the swig executable to use, and --swig-opts to specify options to pass to swig. --swig-opts="-c++" is the new way to spell --swig-cpp. - Patch 983206: distutils now obeys environment variable LDSHARED, if it is set. - Added Peter Astrand's subprocess.py module. See PEP 324 for details. - time.strptime() now properly escapes timezones and all other locale-specific strings for regex-specific symbols. Was breaking under Japanese Windows when the timezone was specified as "Tokyo (standard time)". Closes bug #1039270. - Updates for the email package: + email.Utils.formatdate() grew a 'usegmt' argument for HTTP support. + All deprecated APIs that in email 2.x issued warnings have been removed: _encoder argument to the MIMEText constructor, Message.add_payload(), Utils.dump_address_pair(), Utils.decode(), Utils.encode() + New deprecations: Generator.__call__(), Message.get_type(), Message.get_main_type(), Message.get_subtype(), the 'strict' argument to the Parser constructor. These will be removed in email 3.1. + Support for Python earlier than 2.3 has been removed (see PEP 291). + All defect classes have been renamed to end in 'Defect'. + Some FeedParser fixes; also a MultipartInvariantViolationDefect will be added to messages that claim to be multipart but really aren't. + Updates to documentation. - re's findall() and finditer() functions now take an optional flags argument just like the compile(), search(), and match() functions. Also, documented the previously existing start and stop parameters for the findall() and finditer() methods of regular expression objects. - rfc822 Messages now support iterating over the headers. - The (undocumented) tarfile.Tarfile.membernames has been removed; applications should use the getmember function. - httplib now offers symbolic constants for the HTTP status codes. - SF bug #1028306: Trying to compare a ``datetime.date`` to a ``datetime.datetime`` mistakenly compared only the year, month and day. Now it acts like a mixed-type comparison: ``False`` for ``==``, ``True`` for ``!=``, and raises ``TypeError`` for other comparison operators. Because datetime is a subclass of date, comparing only the base class (date) members can still be done, if that's desired, by forcing using of the approprate date method; e.g., ``a_date.__eq__(a_datetime)`` is true if and only if the year, month and day members of ``a_date`` and ``a_datetime`` are equal. - bdist_rpm now supports command line options --force-arch, {pre,post}-install, {pre,post}-uninstall, and {prep,build,install,clean,verify}-script. - SF patch #998993: The UTF-8 and the UTF-16 stateful decoders now support decoding incomplete input (when the input stream is temporarily exhausted). ``codecs.StreamReader`` now implements buffering, which enables proper readline support for the UTF-16 decoders. ``codecs.StreamReader.read()`` has a new argument ``chars`` which specifies the number of characters to return. ``codecs.StreamReader.readline()`` and ``codecs.StreamReader.readlines()`` have a new argument ``keepends``. Trailing "\n"s will be stripped from the lines if ``keepends`` is false. - The documentation for doctest is greatly expanded, and now covers all the new public features (of which there are many). - ``doctest.master`` was put back in, and ``doctest.testmod()`` once again updates it. This isn't good, because every ``testmod()`` call contributes to bloating the "hidden" state of ``doctest.master``, but some old code apparently relies on it. For now, all we can do is encourage people to stitch doctests together via doctest's unittest integration features instead. - httplib now handles ipv6 address/port pairs. - SF bug #1017864: ConfigParser now correctly handles default keys, processing them with ``ConfigParser.optionxform`` when supplied, consistent with the handling of config file entries and runtime-set options. - SF bug #997050: Document, test, & check for non-string values in ConfigParser. Moved the new string-only restriction added in rev. 1.65 to the SafeConfigParser class, leaving existing ConfigParser & RawConfigParser behavior alone, and documented the conditions under which non-string values work. Build ----- - Building on darwin now includes /opt/local/include and /opt/local/lib for building extension modules. This is so as to include software installed as a DarwinPorts port - pyport.h now defines a Py_IS_NAN macro. It works as-is when the platform C computes true for ``x != x`` if and only if X is a NaN. Other platforms can override the default definition with a platform- specific spelling in that platform's pyconfig.h. You can also override pyport.h's default Py_IS_INFINITY definition now. C API ----- - SF patch 1044089: New function ``PyEval_ThreadsInitialized()`` returns non-zero if PyEval_InitThreads() has been called. - The undocumented and unused extern int ``_PyThread_Started`` was removed. - The C API calls ``PyInterpreterState_New()`` and ``PyThreadState_New()`` are two of the very few advertised as being safe to call without holding the GIL. However, this wasn't true in a debug build, as bug 1041645 demonstrated. In a debug build, Python redirects the ``PyMem`` family of calls to Python's small-object allocator, to get the benefit of its extra debugging capabilities. But Python's small-object allocator isn't threadsafe, relying on the GIL to avoid the expense of doing its own locking. ``PyInterpreterState_New()`` and ``PyThreadState_New()`` call the platform ``malloc()`` directly now, regardless of build type. - PyLong_AsUnsignedLong[Mask] now support int objects as well. - SF patch #998993: ``PyUnicode_DecodeUTF8Stateful`` and ``PyUnicode_DecodeUTF16Stateful`` have been added, which implement stateful decoding. Tests ----- - test__locale ported to unittest Mac --- - ``plistlib`` now supports non-dict root objects. There is also a new interface for reading and writing plist files: ``readPlist(pathOrFile)`` and ``writePlist(rootObject, pathOrFile)`` Tools/Demos ----------- - The text file comparison scripts ``ndiff.py`` and ``diff.py`` now read the input files in universal-newline mode. This spares them from consuming a great deal of time to deduce the useless result that, e.g., a file with Windows line ends and a file with Linux line ends have no lines in common. What's New in Python 2.4 alpha 3? ================================= *Release date: 02-SEP-2004* Core and builtins ----------------- - SF patch #1007189: ``from ... import ...`` statements now allow the name list to be surrounded by parentheses. - Some speedups for long arithmetic, thanks to Trevor Perrin. Gradeschool multiplication was sped a little by optimizing the C code. Gradeschool squaring was sped by about a factor of 2, by exploiting that about half the digit products are duplicates in a square. Because exponentiation uses squaring often, this also speeds long power. For example, the time to compute 17**1000000 dropped from about 14 seconds to 9 on my box due to this much. The cutoff for Karatsuba multiplication was raised, since gradeschool multiplication got quicker, and the cutoff was aggressively small regardless. The exponentiation algorithm was switched from right-to-left to left-to-right, which is more efficient for small bases. In addition, if the exponent is large, the algorithm now does 5 bits (instead of 1 bit) at a time. That cut the time to compute 17**1000000 on my box in half again, down to about 4.5 seconds. - OverflowWarning is no longer generated. PEP 237 scheduled this to occur in Python 2.3, but since OverflowWarning was disabled by default, nobody realized it was still being generated. On the chance that user code is still using them, the Python builtin OverflowWarning, and corresponding C API PyExc_OverflowWarning, will exist until Python 2.5. - Py_InitializeEx has been added. - Fix the order of application of decorators. The proper order is bottom-up; the first decorator listed is the last one called. - SF patch #1005778. Fix a seg fault if the list size changed while calling list.index(). This could happen if a rich comparison function modified the list. - The ``func_name`` (a.k.a. ``__name__``) attribute of user-defined functions is now writable. - code_new (a.k.a new.code()) now checks its arguments sufficiently carefully that passing them on to PyCode_New() won't trigger calls to Py_FatalError() or PyErr_BadInternalCall(). It is still the case that the returned code object might be entirely insane. - Subclasses of string can no longer be interned. The semantics of interning were not clear here -- a subclass could be mutable, for example -- and had bugs. Explicitly interning a subclass of string via intern() will raise a TypeError. Internal operations that attempt to intern a string subclass will have no effect. - Bug 1003935: xrange() could report bogus OverflowErrors. Documented what xrange() intends, and repaired tests accordingly. Extension modules ----------------- - difflib now supports HTML side-by-side diff. - os.urandom has been added for systems that support sources of random data. - Patch 1012740: truncate() on a writeable cStringIO now resets the position to the end of the stream. This is consistent with the original StringIO module and avoids inadvertently resurrecting data that was supposed to have been truncated away. - Added socket.socketpair(). - Added CurrentByteIndex, CurrentColumnNumber, CurrentLineNumber members to xml.parsers.expat.XMLParser object. - The mpz, rotor, and xreadlines modules, all deprecated in earlier versions of Python, have now been removed. Library ------- - Patch #934356: if a module defines __all__, believe that rather than using heuristics for filtering out imported names. - Patch #941486: added os.path.lexists(), which returns True for broken symlinks, unlike os.path.exists(). - the random module now uses os.urandom() for seeding if it is available. Added a new generator based on os.urandom(). - difflib and diff.py can now generate HTML. - bdist_rpm now includes version and release in the BuildRoot, and replaces - by ``_`` in version and release. - distutils build/build_scripts now has an -e option to specify the path to the Python interpreter for installed scripts. - PEP 292 classes Template and SafeTemplate are added to the string module. - tarfile now generates GNU tar files by default. - HTTPResponse has now a getheaders method. - Patch #1006219: let inspect.getsource handle '@' decorators. Thanks Simon Percivall. - logging.handlers.SMTPHandler.date_time has been removed; the class now uses email.Utils.formatdate to generate the time stamp. - A new function tkFont.nametofont was added to return an existing font. The Font class constructor now has an additional exists argument which, if True, requests to return/configure an existing font, rather than creating a new one. - Updated the decimal package's min() and max() methods to match the latest revision of the General Decimal Arithmetic Specification. Quiet NaNs are ignored and equal values are sorted based on sign and exponent. - The decimal package's Context.copy() method now returns deep copies. - Deprecated sys.exitfunc in favor of the atexit module. The sys.exitfunc attribute will be kept around for backwards compatibility and atexit will just become the one preferred way to do it. - patch #675551: Add get_history_item and replace_history_item functions to the readline module. - bug #989672: pdb.doc and the help messages for the help_d and help_u methods of the pdb.Pdb class gives have been corrected. d(own) goes to a newer frame, u(p) to an older frame, not the other way around. - bug #990669: os.path.realpath() will resolve symlinks before normalizing the path, as normalizing the path may alter the meaning of the path if it contains symlinks. - bug #851123: shutil.copyfile will raise an exception when trying to copy a file onto a link to itself. Thanks Gregory Ball. - bug #570300: Fix inspect to resolve file locations using os.path.realpath() so as to properly list all functions in a module when the module itself is reached through a symlink. Thanks Johannes Gijsbers. - doctest refactoring continued. See the docs for details. As part of this effort, some old and little- (never?) used features are now deprecated: the Tester class, the module is_private() function, and the isprivate argument to testmod(). The Tester class supplied a feeble "by hand" way to combine multiple doctests, if you knew exactly what you were doing. The newer doctest features for unittest integration already did a better job of that, are stronger now than ever, and the new DocTestRunner class is a saner foundation if you want to do it by hand. The "private name" filtering gimmick was a mistake from the start, and testmod() changed long ago to ignore it by default. If you want to filter out tests, the new DocTestFinder class can be used to return a list of all doctests, and you can filter that list by any computable criteria before passing it to a DocTestRunner instance. - Bug #891637, patch #1005466: fix inspect.getargs() crash on def foo((bar)). Tools/Demos ----------- - IDLE's shortcut keys for windows are now case insensitive so that Control-V works the same as Control-v. - pygettext.py: Generate POT-Creation-Date header in ISO format. Build ----- - Backward incompatibility: longintrepr.h now triggers a compile-time error if SHIFT (the number of bits in a Python long "digit") isn't divisible by 5. This new requirement allows simple code for the new 5-bits-at-a-time long_pow() implementation. If necessary, the restriction could be removed (by complicating long_pow(), or by falling back to the 1-bit-at-a-time algorithm), but there are no plans to do so. - bug #991962: When building with --disable-toolbox-glue on Darwin no attempt to build Mac-specific modules occurs. - The --with-tsc flag to configure to enable VM profiling with the processor's timestamp counter now works on PPC platforms. - patch #1006629: Define _XOPEN_SOURCE to 500 on Solaris 8/9 to match GCC's definition and avoid redefinition warnings. - Detect pthreads support (provided by gnu pth pthread emulation) on GNU/k*BSD systems. - bug #1005737, #1007249: Fixed several build problems and warnings found on old/legacy C compilers of HP-UX, IRIX and Tru64. C API ----- .. Documentation ------------- - patch #1005936, bug #1009373: fix index entries which contain an underscore when viewed with Acrobat. - bug #990669: os.path.normpath may alter the meaning of a path if it contains symbolic links. This has been documented in a comment since 1992, but is now in the library reference as well. New platforms ------------- - FreeBSD 6 is now supported. Tests ----- .. Windows ------- - Boosted the stack reservation for python.exe and pythonw.exe from the default 1MB to 2MB. Stack frames under VC 7.1 for 2.4 are enough bigger than under VC 6.0 for 2.3.4 that deeply recursive progams within the default sys.getrecursionlimit() default value of 1000 were able to suffer undetected C stack overflows. The standard test program test_compiler was one such program. If a Python process on Windows "just vanishes" without a trace, and without an error message of any kind, but with an exit code of 128, undetected stack overflow may be the problem. Mac --- .. What's New in Python 2.4 alpha 2? ================================= *Release date: 05-AUG-2004* Core and builtins ----------------- - Patch #980695: Implements efficient string concatenation for statements of the form s=s+t and s+=t. This will vary across implementations. Accordingly, the str.join() method is strongly preferred for performance sensitive code. - PEP-0318, Function Decorators have been added to the language. These are implemented using the Java-style @decorator syntax, like so:: @staticmethod def foo(bar): (The PEP needs to be updated to reflect the current state) - When importing a module M raises an exception, Python no longer leaves M in sys.modules. Before 2.4a2 it did, and a subsequent import of M would succeed, picking up a module object from sys.modules reflecting as much of the initialization of M as completed before the exception was raised. Subsequent imports got no indication that M was in a partially- initialized state, and the importers could get into arbitrarily bad trouble as a result (the M they got was in an unintended state, arbitrarily far removed from M's author's intent). Now subsequent imports of M will continue raising exceptions (but if, for example, the source code for M is edited between import attempts, then perhaps later attempts will succeed, or raise a different exception). This can break existing code, but in such cases the code was probably working before by accident. In the Python source, the only case of breakage discovered was in a test accidentally relying on a damaged module remaining in sys.modules. Cases are also known where tests deliberately provoking import errors remove damaged modules from sys.modules themselves, and such tests will break now if they do an unconditional del sys.modules[M]. - u'%s' % obj will now try obj.__unicode__() first and fallback to obj.__str__() if no __unicode__ method can be found. - Patch #550732: Add PyArg_VaParseTupleAndKeywords(). Analogous to PyArg_VaParse(). Both are now documented. Thanks Greg Chapman. - Allow string and unicode return types from .encode()/.decode() methods on string and unicode objects. Added unicode.decode() which was missing for no apparent reason. - An attempt to fix the mess that is Python's behaviour with signal handlers and threads, complicated by readline's behaviour. It's quite possible that there are still bugs here. - Added C macros Py_CLEAR and Py_VISIT to ease the implementation of types that support garbage collection. - Compiler now treats None as a constant. - The type of values returned by __int__, __float__, __long__, __oct__, and __hex__ are now checked. Returning an invalid type will cause a TypeError to be raised. This matches the behavior of Jython. - Implemented bind_textdomain_codeset() in locale module. - Added a workaround for proper string operations in BSDs. str.split and str.is* methods can now work correctly with UTF-8 locales. - Bug #989185: unicode.iswide() and unicode.width() is dropped and the East Asian Width support is moved to unicodedata extension module. - Patch #941229: The source code encoding in interactive mode now refers sys.stdin.encoding not just ISO-8859-1 anymore. This allows for non-latin-1 users to write unicode strings directly. Extension modules ----------------- - cpickle now supports the same keyword arguments as pickle. Library ------- - Added new codecs and aliases for ISO_8859-11, ISO_8859-16 and TIS-620 - Thanks to Edward Loper, doctest has been massively refactored, and many new features were added. Full docs will appear later. For now the doctest module comments and new test cases give good coverage. The refactoring provides many hook points for customizing behavior (such as how to report errors, and how to compare expected to actual output). New features include a marker for expected output containing blank lines, options to produce unified or context diffs when actual output doesn't match expectations, an option to normalize whitespace before comparing, and an option to use an ellipsis to signify "don't care" regions of output. - Tkinter now supports the wish -sync and -use options. - The following methods in time support passing of None: ctime(), gmtime(), and localtime(). If None is provided, the current time is used (the same as when the argument is omitted). [SF bug 658254, patch 663482] - nntplib does now allow to ignore a .netrc file. - urllib2 now recognizes Basic authentication even if other authentication schemes are offered. - Bug #1001053. wave.open() now accepts unicode filenames. - gzip.GzipFile has a new fileno() method, to retrieve the handle of the underlying file object (provided it has a fileno() method). This is needed if you want to use os.fsync() on a GzipFile. - imaplib has two new methods: deleteacl and myrights. - nntplib has two new methods: description and descriptions. They use a more RFC-compliant way of getting a newsgroup description. - Bug #993394. Fix a possible red herring of KeyError in 'threading' being raised during interpreter shutdown from a registered function with atexit when dummy_threading is being used. - Bug #857297/Patch #916874. Fix an error when extracting a hard link from a tarfile. - Patch #846659. Fix an error in tarfile.py when using GNU longname/longlink creation. - The obsolete FCNTL.py has been deleted. The builtin fcntl module has been available (on platforms that support fcntl) since Python 1.5a3, and all FCNTL.py did is export fcntl's names, after generating a deprecation warning telling you to use fcntl directly. - Several new unicode codecs are added: big5hkscs, euc_jis_2004, iso2022_jp_2004, shift_jis_2004. - Bug #788520. Queue.{get, get_nowait, put, put_nowait} have new implementations, exploiting Conditions (which didn't exist at the time Queue was introduced). A minor semantic change is that the Full and Empty exceptions raised by non-blocking calls now occur only if the queue truly was full or empty at the instant the queue was checked (of course the Queue may no longer be full or empty by the time a calling thread sees those exceptions, though). Before, the exceptions could also be raised if it was "merely inconvenient" for the implementation to determine the true state of the Queue (because the Queue was locked by some other method in progress). - Bugs #979794 and #980117: difflib.get_grouped_opcodes() now handles the case of comparing two empty lists. This affected both context_diff() and unified_diff(), - Bug #980938: smtplib now prints debug output to sys.stderr. - Bug #930024: posixpath.realpath() now handles infinite loops in symlinks by returning the last point in the path that was not part of any loop. Thanks AM Kuchling. - Bug #980327: ntpath not handles compressing erroneous slashes between the drive letter and the rest of the path. Also clearly handles UNC addresses now as well. Thanks Paul Moore. - bug #679953: zipfile.py should now work for files over 2 GB. The packed data for file sizes (compressed and uncompressed) was being stored as signed instead of unsigned. - decimal.py now only uses signals in the IBM spec. The other conditions are no longer part of the public API. - codecs module now has two new generic APIs: encode() and decode() which don't restrict the return types (unlike the unicode and string methods of the same name). - Non-blocking SSL sockets work again; they were broken in Python 2.3. SF patch 945642. - doctest unittest integration improvements: o Improved the unitest test output for doctest-based unit tests o Can now pass setUp and tearDown functions when creating DocTestSuites. - The threading module has a new class, local, for creating objects that provide thread-local data. - Bug #990307: when keep_empty_values is True, cgi.parse_qsl() no longer returns spurious empty fields. - Implemented bind_textdomain_codeset() in gettext module. - Introduced in gettext module the l*gettext() family of functions, which return translation strings encoded in the preferred encoding, as informed by locale module's getpreferredencoding(). - optparse module (and tests) upgraded to Optik 1.5a1. Changes: - Add expansion of default values in help text: the string "%default" in an option's help string is expanded to str() of that option's default value, or "none" if no default value. - Bug #955889: option default values that happen to be strings are now processed in the same way as values from the command line; this allows generation of nicer help when using custom types. Can be disabled with parser.set_process_default_values(False). - Bug #960515: don't crash when generating help for callback options that specify 'type', but not 'dest' or 'metavar'. - Feature #815264: change the default help format for short options that take an argument from e.g. "-oARG" to "-o ARG"; add set_short_opt_delimiter() and set_long_opt_delimiter() methods to HelpFormatter to allow (slight) customization of the formatting. - Patch #736940: internationalize Optik: all built-in user- targeted literal strings are passed through gettext.gettext(). (If you want translations (.po files), they're not included with Python -- you'll find them in the Optik source distribution from http://optik.sourceforge.net/ .) - Bug #878453: respect $COLUMNS environment variable for wrapping help output. - Feature #988122: expand "%prog" in the 'description' passed to OptionParser, just like in the 'usage' and 'version' strings. (This is *not* done in the 'description' passed to OptionGroup.) C API ----- - PyImport_ExecCodeModule() and PyImport_ExecCodeModuleEx(): if an error occurs while loading the module, these now delete the module's entry from sys.modules. All ways of loading modules eventually call one of these, so this is an error-case change in semantics for all ways of loading modules. In rare cases, a module loader may wish to keep a module object in sys.modules despite that the module's code cannot be executed. In such cases, the module loader must arrange to reinsert the name and module object in sys.modules. PyImport_ReloadModule() has been changed to reinsert the original module object into sys.modules if the module reload fails, so that its visible semantics have not changed. - A large pile of datetime field-extraction macros is now documented, thanks to Anthony Tuininga (patch #986010). Documentation ------------- - Improved the tutorial on creating types in C. - point out the importance of reassigning data members before assigning their values - correct my misconception about return values from visitprocs. Sigh. - mention the labor saving Py_VISIT and Py_CLEAR macros. - Major rewrite of the math module docs, to address common confusions. Tests ----- - The test data files for the decimal test suite are now installed on platforms that use the Makefile. - SF patch 995225: The test file testtar.tar accidentally contained CVS keywords (like $Id: HISTORY 43159 2006-03-20 06:30:41Z anthony.baxter $), which could cause spurious failures in test_tarfile.py depending on how the test file was checked out. What's New in Python 2.4 alpha 1? ================================= *Release date: 08-JUL-2004* Core and builtins ----------------- - weakref.ref is now the type object also known as weakref.ReferenceType; it can be subclassed like any other new-style class. There's less per-entry overhead in WeakValueDictionary objects now (one object instead of three). - Bug #951851: Python crashed when reading import table of certain Windows DLLs. - Bug #215126. The locals argument to eval(), execfile(), and exec now accept any mapping type. - marshal now shares interned strings. This change introduces a new .pyc magic. - Bug #966623. classes created with type() in an exec(, {}) don't have a __module__, but code in typeobject assumed it would always be there. - Python no longer relies on the LC_NUMERIC locale setting to be the "C" locale; as a result, it no longer tries to prevent changing the LC_NUMERIC category. - Bug #952807: Unpickling pickled instances of subclasses of datetime.date, datetime.datetime and datetime.time could yield insane objects. Thanks to Jiwon Seo for a fix. - Bug #845802: Python crashes when __init__.py is a directory. - Unicode objects received two new methods: iswide() and width(). These query East Asian width information, as specified in Unicode TR11. - Improved the tuple hashing algorithm to give fewer collisions in common cases. Fixes bug #942952. - Implemented generator expressions (PEP 289). Coded by Jiwon Seo. - Enabled the profiling of C extension functions (and builtins) - check new documentation and modified profile and bdb modules for more details - Set file.name to the object passed to open (instead of a new string) - Moved tracebackobject into traceback.h and renamed to PyTracebackObject - Optimized the byte coding for multiple assignments like "a,b=b,a" and "a,b,c=1,2,3". Improves their speed by 25% to 30%. - Limit the nested depth of a tuple for the second argument to isinstance() and issubclass() to the recursion limit of the interpreter. Fixes bug #858016 . - Optimized dict iterators, creating separate types for each and having them reveal their length. Also optimized the methods: keys(), values(), and items(). - Implemented a newcode opcode, LIST_APPEND, that simplifies the generated bytecode for list comprehensions and further improves their performance (about 35%). - Implemented rich comparisons for floats, which seems to make comparisons involving NaNs somewhat less surprising when the underlying C compiler actually implements C99 semantics. - Optimized list.extend() to save memory and no longer create intermediate sequences. Also, extend() now pre-allocates the needed memory whenever the length of the iterable is known in advance -- this halves the time to extend the list. - Optimized list resize operations to make fewer calls to the system realloc(). Significantly speeds up list appends, list pops, list comprehensions, and the list constructor (when the input iterable length is not known). - Changed the internal list over-allocation scheme. For larger lists, overallocation ranged between 3% and 25%. Now, it is a constant 12%. For smaller lists (n<8), overallocation was upto eight elements. Now, the overallocation is no more than three elements -- this improves space utilization for applications that have large numbers of small lists. - Most list bodies now get re-used rather than freed. Speeds up list instantiation and deletion by saving calls to malloc() and free(). - The dict.update() method now accepts all the same argument forms as the dict() constructor. This now includes item lists and/or keyword arguments. - Support for arbitrary objects supporting the read-only buffer interface as the co_code field of code objects (something that was only possible to create from C code) has been removed. - Made omitted callback and None equivalent for weakref.ref() and weakref.proxy(); the None case wasn't handled correctly in all cases. - Fixed problem where PyWeakref_NewRef() and PyWeakref_NewProxy() assumed that initial existing entries in an object's weakref list would not be removed while allocating a new weakref object. Since GC could be invoked at that time, however, that assumption was invalid. In a truly obscure case of GC being triggered during creation for a new weakref object for an referent which already has a weakref without a callback which is only referenced from cyclic trash, a memory error can occur. This consistently created a segfault in a debug build, but provided less predictable behavior in a release build. - input() builtin function now respects compiler flags such as __future__ statements. SF patch 876178. - Removed PendingDeprecationWarning from apply(). apply() remains deprecated, but the nuisance warning will not be issued. - At Python shutdown time (Py_Finalize()), 2.3 called cyclic garbage collection twice, both before and after tearing down modules. The call after tearing down modules has been disabled, because too much of Python has been torn down then for __del__ methods and weakref callbacks to execute sanely. The most common symptom was a sequence of uninformative messages on stderr when Python shut down, produced by threads trying to raise exceptions, but unable to report the nature of their problems because too much of the sys module had already been destroyed. - Removed FutureWarnings related to hex/oct literals and conversions and left shifts. (Thanks to Kalle Svensson for SF patch 849227.) This addresses most of the remaining semantic changes promised by PEP 237, except for repr() of a long, which still shows the trailing 'L'. The PEP appears to promise warnings for operations that changed semantics compared to Python 2.3, but this is not implemented; we've suffered through enough warnings related to hex/oct literals and I think it's best to be silent now. - For str and unicode objects, the ljust(), center(), and rjust() methods now accept an optional argument specifying a fill character other than a space. - When method objects have an attribute that can be satisfied either by the function object or by the method object, the function object's attribute usually wins. Christian Tismer pointed out that that this is really a mistake, because this only happens for special methods (like __reduce__) where the method object's version is really more appropriate than the function's attribute. So from now on, all method attributes will have precedence over function attributes with the same name. - Critical bugfix, for SF bug 839548: if a weakref with a callback, its callback, and its weakly referenced object, all became part of cyclic garbage during a single run of garbage collection, the order in which they were torn down was unpredictable. It was possible for the callback to see partially-torn-down objects, leading to immediate segfaults, or, if the callback resurrected garbage objects, to resurrect insane objects that caused segfaults (or other surprises) later. In one sense this wasn't surprising, because Python's cyclic gc had no knowledge of Python's weakref objects. It does now. When weakrefs with callbacks become part of cyclic garbage now, those weakrefs are cleared first. The callbacks don't trigger then, preventing the problems. If you need callbacks to trigger, then just as when cyclic gc is not involved, you need to write your code so that weakref objects outlive the objects they weakly reference. - Critical bugfix, for SF bug 840829: if cyclic garbage collection happened to occur during a weakref callback for a new-style class instance, subtle memory corruption was the result (in a release build; in a debug build, a segfault occurred reliably very soon after). This has been repaired. - Compiler flags set in PYTHONSTARTUP are now active in __main__. - Added two builtin types, set() and frozenset(). - Added a reversed() builtin function that returns a reverse iterator over a sequence. - Added a sorted() builtin function that returns a new sorted list from any iterable. - CObjects are now mutable (on the C level) through PyCObject_SetVoidPtr. - list.sort() now supports three keyword arguments: cmp, key, and reverse. The key argument can be a function of one argument that extracts a comparison key from the original record: mylist.sort(key=str.lower). The reverse argument is a boolean value and if True will change the sort order as if the comparison arguments were reversed. In addition, the documentation has been amended to provide a guarantee that all sorts starting with Py2.3 are guaranteed to be stable (the relative order of records with equal keys is unchanged). - Added test whether wchar_t is signed or not. A signed wchar_t is not usable as internal unicode type base for Py_UNICODE since the unicode implementation assumes an unsigned type. - Fixed a bug in the cache of length-one Unicode strings that could lead to a seg fault. The specific problem occurred when an earlier, non-fatal error left an uninitialized Unicode object in the freelist. - The % formatting operator now supports '%F' which is equivalent to '%f'. This has always been documented but never implemented. - complex(obj) could leak a little memory if obj wasn't a string or number. - zip() with no arguments now returns an empty list instead of raising a TypeError exception. - obj.__contains__() now returns True/False instead of 1/0. SF patch 820195. - Python no longer tries to be smart about recursive comparisons. When comparing containers with cyclic references to themselves it will now just hit the recursion limit. See SF patch 825639. - str and unicode builtin types now have an rsplit() method that is same as split() except that it scans the string from the end working towards the beginning. See SF feature request 801847. - Fixed a bug in object.__reduce_ex__ when using protocol 2. Failure to clear the error when attempts to get the __getstate__ attribute fail caused intermittent errors and odd behavior. - buffer objects based on other objects no longer cache a pointer to the data and the data length. Instead, the appropriate tp_as_buffer method is called as necessary. - fixed: if a file is opened with an explicit buffer size >= 1, repeated close() calls would attempt to free() the buffer already free()ed on the first call. Extension modules ----------------- - Added socket.getservbyport(), and make the second argument in getservbyname() and getservbyport() optional. - time module code that deals with input POSIX timestamps will now raise ValueError if more than a second is lost in precision when the timestamp is cast to the platform C time_t type. There's no chance that the platform will do anything sensible with the result in such cases. This includes ctime(), localtime() and gmtime(). Assorted fromtimestamp() and utcfromtimestamp() methods in the datetime module were also protected. Closes bugs #919012 and 975996. - fcntl.ioctl now warns if the mutate flag is not specified. - nt now properly allows to refer to UNC roots, e.g. in nt.stat(). - the weakref module now supports additional objects: array.array, sre.pattern_objects, file objects, and sockets. - operator.isMappingType() and operator.isSequenceType() now give fewer false positives. - socket.sslerror is now a subclass of socket.error . Also added socket.error to the socket module's C API. - Bug #920575: A problem where the _locale module segfaults on nl_langinfo(ERA) caused by GNU libc's illegal NULL return is fixed. - array objects now support the copy module. Also, their resizing scheme has been updated to match that used for list objects. This improves the performance (speed and memory usage) of append() operations. Also, array.array() and array.extend() now accept any iterable argument for repeated appends without needing to create another temporary array. - cStringIO.writelines() now accepts any iterable argument and writes the lines one at a time rather than joining them and writing once. Made a parallel change to StringIO.writelines(). Saves memory and makes suitable for use with generator expressions. - time.strftime() now checks that the values in its time tuple argument are within the proper boundaries to prevent possible crashes from the platform's C library implementation of strftime(). Can possibly break code that uses values outside the range that didn't cause problems previously (such as sitting day of year to 0). Fixes bug #897625. - The socket module now supports Bluetooth sockets, if the system has - Added a collections module containing a new datatype, deque(), offering high-performance, thread-safe, memory friendly appends and pops on either side of the deque. - Several modules now take advantage of collections.deque() for improved performance: Queue, mutex, shlex, threading, and pydoc. - The operator module has two new functions, attrgetter() and itemgetter() which are useful for creating fast data extractor functions for map(), list.sort(), itertools.groupby(), and other functions that expect a function argument. - socket.SHUT_{RD,WR,RDWR} was added. - os.getsid was added. - The pwd module incorrectly advertised its struct type as struct_pwent; this has been renamed to struct_passwd. (The old name is still supported for backwards compatibility.) - The xml.parsers.expat module now provides Expat 1.95.7. - socket.IPPROTO_IPV6 was added. - readline.clear_history was added. - select.select() now accepts sequences for its first three arguments. - cStringIO now supports the f.closed attribute. - The signal module now exposes SIGRTMIN and SIGRTMAX (if available). - curses module now supports use_default_colors(). [patch #739124] - Bug #811028: ncurses.h breakage on FreeBSD/MacOS X - Bug #814613: INET_ADDRSTRLEN fix needed for all compilers on SGI - Implemented non-recursive SRE matching scheme (#757624). - Implemented (?(id/name)yes|no) support in SRE (#572936). - random.seed() with no arguments or None uses time.time() as a default seed. Modified to match Py2.2 behavior and use fractional seconds so that successive runs are more likely to produce different sequences. - random.Random has a new method, getrandbits(k), which returns an int with k random bits. This method is now an optional part of the API for user defined generators. Any generator that defines genrandbits() can now use randrange() for ranges with a length >= 2**53. Formerly, randrange would return only even numbers for ranges that large (see SF bug #812202). Generators that do not define genrandbits() now issue a warning when randrange() is called with a range that large. - itertools has a new function, groupby() for aggregating iterables into groups sharing the same key (as determined by a key function). It offers some of functionality of SQL's groupby keyword and of the Unix uniq filter. - itertools now has a new tee() function which produces two independent iterators from a single iterable. - itertools.izip() with no arguments now returns an empty iterator instead of raising a TypeError exception. - Fixed #853061: allow BZ2Compressor.compress() to receive an empty string as parameter. Library ------- - Added a new module: cProfile, a C profiler with the same interface as the profile module. cProfile avoids some of the drawbacks of the hotshot profiler and provides a bit more information than the other two profilers. Based on "lsprof" (patch #1212837). - Bug #1266283: The new function "lexists" is now in os.path.__all__. - Bug #981530: Fix UnboundLocalError in shutil.rmtree(). This affects the documented behavior: the function passed to the onerror() handler can now also be os.listdir. - Bug #754449: threading.Thread objects no longer mask exceptions raised during interpreter shutdown with another exception from attempting to handle the original exception. - Added decimal.py per PEP 327. - Bug #981299: rsync is now a recognized protocol in urlparse that uses a "netloc" portion of a URL. - Bug #919012: shutil.move() will not try to move a directory into itself. Thanks Johannes Gijsbers. - Bug #934282: pydoc.stripid() is now case-insensitive. Thanks Robin Becker. - Bug #823209: cmath.log() now takes an optional base argument so that its API matches math.log(). - Bug #957381: distutils bdist_rpm no longer fails on recent RPM versions that generate a -debuginfo.rpm - os.path.devnull has been added for all supported platforms. - Fixed #877165: distutils now picks the right C++ compiler command on cygwin and mingw32. - urllib.urlopen().readline() now handles HTTP/0.9 correctly. - refactored site.py into functions. Also wrote regression tests for the module. - The distutils install command now supports the --home option and installation scheme for all platforms. - asyncore.loop now has a repeat count parameter that defaults to looping forever. - The distutils sdist command now ignores all .svn directories, in addition to CVS and RCS directories. .svn directories hold administrative files for the Subversion source control system. - Added a new module: cookielib. Automatic cookie handling for HTTP clients. Also, support for cookielib has been added to urllib2, so urllib2.urlopen() can transparently handle cookies. - stringprep.py now uses built-in set() instead of sets.Set(). - Bug #876278: Unbounded recursion in modulefinder - Bug #780300: Swap public and system ID in LexicalHandler.startDTD. Applications relying on the wrong order need to be corrected. - Bug #926075: Fixed a bug that returns a wrong pattern object for a string or unicode object in sre.compile() when a different type pattern with the same value exists. - Added countcallers arg to trace.Trace class (--trackcalls command line arg when run from the command prompt). - Fixed a caching bug in platform.platform() where the argument of 'terse' was not taken into consideration when caching value. - Added two new command-line arguments for profile (output file and default sort). - Added global runctx function to profile module - Add hlist missing entryconfigure and entrycget methods. - The ptcp154 codec was added for Kazakh character set support. - Support non-anonymous ftp URLs in urllib2. - The encodings package will now apply codec name aliases first before starting to try the import of the codec module. This simplifies overriding built-in codecs with external packages, e.g. the included CJK codecs with the JapaneseCodecs package, by adjusting the aliases dictionary in encodings.aliases accordingly. - base64 now supports RFC 3548 Base16, Base32, and Base64 encoding and decoding standards. - urllib2 now supports processors. A processor is a handler that implements an xxx_request or xxx_response method. These methods are called for all requests. - distutils compilers now compile source files in the same order as they are passed to the compiler. - pprint.pprint() and pprint.pformat() now have additional parameters indent, width and depth. - Patch #750542: pprint now will pretty print subclasses of list, tuple and dict too, as long as they don't overwrite __repr__(). - Bug #848614: distutils' msvccompiler fails to find the MSVC6 compiler because of incomplete registry entries. - httplib.HTTP.putrequest now offers to omit the implicit Accept-Encoding. - Patch #841977: modulefinder didn't find extension modules in packages - imaplib.IMAP4.thread was added. - Plugged a minor hole in tempfile.mktemp() due to the use of os.path.exists(), switched to using os.lstat() directly if possible. - bisect.py and heapq.py now have underlying C implementations for better performance. - heapq.py has two new functions, nsmallest() and nlargest(). - traceback.format_exc has been added (similar to print_exc but it returns a string). - xmlrpclib.MultiCall has been added. - poplib.POP3_SSL has been added. - tmpfile.mkstemp now returns an absolute path even if dir is relative. - urlparse is RFC 2396 compliant. - The fieldnames argument to the csv module's DictReader constructor is now optional. If omitted, the first row of the file will be used as the list of fieldnames. - encodings.bz2_codec was added for access to bz2 compression using "a long string".encode('bz2') - Various improvements to unittest.py, realigned with PyUnit CVS. - dircache now passes exceptions to the caller, instead of returning empty lists. - The bsddb module and dbhash module now support the iterator and mapping protocols which make them more substitutable for dictionaries and shelves. - The csv module's DictReader and DictWriter classes now accept keyword arguments. This was an omission in the initial implementation. - The email package handles some RFC 2231 parameters with missing CHARSET fields better. It also includes a patch to parameter parsing when semicolons appear inside quotes. - sets.py now runs under Py2.2. In addition, the argument restrictions for most set methods (but not the operators) have been relaxed to allow any iterable. - _strptime.py now has a behind-the-scenes caching mechanism for the most recent TimeRE instance used along with the last five unique directive patterns. The overall module was also made more thread-safe. - random.cunifvariate() and random.stdgamma() were deprecated in Py2.3 and removed in Py2.4. - Bug #823328: urllib2.py's HTTP Digest Auth support works again. - Patch #873597: CJK codecs are imported into rank of default codecs. Tools/Demos ----------- - A hotshotmain script was added to the Tools/scripts directory that makes it easy to run a script under control of the hotshot profiler. - The db2pickle and pickle2db scripts can now dump/load gdbm files. - The file order on the command line of the pickle2db script was reversed. It is now [ picklefile ] dbfile. This provides better symmetry with db2pickle. The file arguments to both scripts are now source followed by destination in situations where both files are given. - The pydoc script will display a link to the module documentation for modules determined to be part of the core distribution. The documentation base directory defaults to http://www.python.org/doc/current/lib/ but can be changed by setting the PYTHONDOCS environment variable. - texcheck.py now detects double word errors. - md5sum.py mistakenly opened input files in text mode by default, a silent and dangerous change from previous releases. It once again opens input files in binary mode by default. The -t and -b flags remain for compatibility with the 2.3 release, but -b is the default now. - py-electric-colon now works when pending-delete/delete-selection mode is in effect - py-help-at-point is no longer bound to the F1 key - it's still bound to C-c C-h - Pynche was fixed to not crash when there is no ~/.pynche file and no -d option was given. Build ----- - Bug #978645: Modules/getpath.c now builds properly in --disable-framework build under OS X. - Profiling using gprof is now available if Python is configured with --enable-profiling. - Profiling the VM using the Pentium TSC is now possible if Python is configured --with-tsc. - In order to find libraries, setup.py now also looks in /lib64, for use on AMD64. - Bug #934635: Fixed a bug where the configure script couldn't detect getaddrinfo() properly if the KAME stack had SCTP support. - Support for missing ANSI C header files (limits.h, stddef.h, etc) was removed. - Systems requiring the D4, D6 or D7 variants of pthreads are no longer supported (see PEP 11). - Universal newline support can no longer be disabled (see PEP 11). - Support for DGUX, SunOS 4, IRIX 4 and Minix was removed (see PEP 11). - Support for systems requiring --with-dl-dld or --with-sgi-dl was removed (see PEP 11). - Tests for sizeof(char) were removed since ANSI C mandates that sizeof(char) must be 1. C API ----- - Thanks to Anthony Tuininga, the datetime module now supplies a C API containing type-check macros and constructors. See new docs in the Python/C API Reference Manual for details. - Private function _PyTime_DoubleToTimet added, to convert a Python timestamp (C double) to platform time_t with some out-of-bounds checking. Declared in new header file timefuncs.h. It would be good to expose some other internal timemodule.c functions there. - New public functions PyEval_EvaluateFrame and PyGen_New to expose generator objects. - New public functions Py_IncRef() and Py_DecRef(), exposing the functionality of the Py_XINCREF() and Py_XDECREF macros. Useful for runtime dynamic embedding of Python. See patch #938302, by Bob Ippolito. - Added a new macro, PySequence_Fast_ITEMS, which retrieves a fast sequence's underlying array of PyObject pointers. Useful for high speed looping. - Created a new method flag, METH_COEXIST, which causes a method to be loaded even if already defined by a slot wrapper. This allows a __contains__ method, for example, to co-exist with a defined sq_contains slot. This is helpful because the PyCFunction can take advantage of optimized calls whenever METH_O or METH_NOARGS flags are defined. - Added a new function, PyDict_Contains(d, k) which is like PySequence_Contains() but is specific to dictionaries and executes about 10% faster. - Added three new macros: Py_RETURN_NONE, Py_RETURN_TRUE, and Py_RETURN_FALSE. Each return the singleton they mention after Py_INCREF()ing them. - Added a new function, PyTuple_Pack(n, ...) for constructing tuples from a variable length argument list of Python objects without having to invoke the more complex machinery of Py_BuildValue(). PyTuple_Pack(3, a, b, c) is equivalent to Py_BuildValue("(OOO)", a, b, c). Windows ------- - The _winreg module could segfault when reading very large registry values, due to unchecked alloca() calls (SF bug 851056). The fix is uses either PyMem_Malloc(n) or PyString_FromStringAndSize(NULL, n), as appropriate, followed by a size check. - file.truncate() could misbehave if the file was open for update (modes r+, rb+, w+, wb+), and the most recent file operation before the truncate() call was an input operation. SF bug 801631. What's New in Python 2.3 final? =============================== *Release date: 29-Jul-2003* IDLE ---- - Bug 778400: IDLE hangs when selecting "Edit with IDLE" from explorer. This was unique to Windows, and was fixed by adding an -n switch to the command the Windows installer creates to execute "Edit with IDLE" context-menu actions. - IDLE displays a new message upon startup: some "personal firewall" kinds of programs (for example, ZoneAlarm) open a dialog of their own when any program opens a socket. IDLE does use sockets, talking on the computer's internal loopback interface. This connection is not visible on any external interface and no data is sent to or received from the Internet. So, if you get such a dialog when opening IDLE, asking whether to let pythonw.exe talk to address 127.0.0.1, say yes, and rest assured no communication external to your machine is taking place. If you don't allow it, IDLE won't be able to start. What's New in Python 2.3 release candidate 2? ============================================= *Release date: 24-Jul-2003* Core and builtins ----------------- - It is now possible to import from zipfiles containing additional data bytes before the zip compatible archive. Zipfiles containing a comment at the end are still unsupported. Extension modules ----------------- - A longstanding bug in the parser module's initialization could cause fatal internal refcount confusion when the module got initialized more than once. This has been fixed. - Fixed memory leak in pyexpat; using the parser's ParseFile() method with open files that aren't instances of the standard file type caused an instance of the bound .read() method to be leaked on every call. - Fixed some leaks in the locale module. Library ------- - Lib/encodings/rot_13.py when used as a script, now more properly uses the first Python interpreter on your path. - Removed caching of TimeRE (and thus LocaleTime) in _strptime.py to fix a locale related bug in the test suite. Although another patch was needed to actually fix the problem, the cache code was not restored. IDLE ---- - Calltips patches. Build ----- - For MacOSX, added -mno-fused-madd to BASECFLAGS to fix test_coercion on Panther (OSX 10.3). C API ----- Windows ------- - The tempfile module could do insane imports on Windows if PYTHONCASEOK was set, making temp file creation impossible. Repaired. - Add a patch to workaround pthread_sigmask() bugs in Cygwin. Mac --- - Various fixes to pimp. - Scripts runs with pythonw no longer had full window manager access. - Don't force boot-disk-only install, for reasons unknown it causes more problems than it solves. What's New in Python 2.3 release candidate 1? ============================================= *Release date: 18-Jul-2003* Core and builtins ----------------- - The new function sys.getcheckinterval() returns the last value set by sys.setcheckinterval(). - Several bugs in the symbol table phase of the compiler have been fixed. Errors could be lost and compilation could fail without reporting an error. SF patch 763201. - The interpreter is now more robust about importing the warnings module. In an executable generated by freeze or similar programs, earlier versions of 2.3 would fail if the warnings module could not be found on the file system. Fixes SF bug 771097. - A warning about assignments to module attributes that shadow builtins, present in earlier releases of 2.3, has been removed. - It is not possible to create subclasses of builtin types like str and tuple that define an itemsize. Earlier releases of Python 2.3 allowed this by mistake, leading to crashes and other problems. - The thread_id is now initialized to 0 in a non-thread build. SF bug 770247. - SF bug 762891: "del p[key]" on proxy object no longer raises SystemError. Extension modules ----------------- - weakref.proxy() can now handle "del obj[i]" for proxy objects defining __delitem__. Formerly, it generated a SystemError. - SSL no longer crashes the interpreter when the remote side disconnects. - On Unix the mmap module can again be used to map device files. - time.strptime now exclusively uses the Python implementation contained within the _strptime module. - The print slot of weakref proxy objects was removed, because it was not consistent with the object's repr slot. - The mmap module only checks file size for regular files, not character or block devices. SF patch 708374. - The cPickle Pickler garbage collection support was fixed to traverse the find_class attribute, if present. - There are several fixes for the bsddb3 wrapper module. bsddb3 no longer crashes if an environment is closed before a cursor (SF bug 763298). The DB and DBEnv set_get_returns_none function was extended to take a level instead of a boolean flag. The new level 2 means that in addition, cursor.set()/.get() methods return None instead of raising an exception. A typo was fixed in DBCursor.join_item(), preventing a crash. Library ------- - distutils now supports MSVC 7.1 - doctest now examines all docstrings by default. Previously, it would skip over functions with private names (as indicated by the underscore naming convention). The old default created too much of a risk that user tests were being skipped inadvertently. Note, this change could break code in the unlikely case that someone had intentionally put failing tests in the docstrings of private functions. The breakage is easily fixable by specifying the old behavior when calling testmod() or Tester(). - There were several fixes to the way dumbdbms are closed. It's vital that a dumbdbm database be closed properly, else the on-disk data and directory files can be left in mutually inconsistent states. dumbdbm.py's _Database.__del__() method attempted to close the database properly, but a shutdown race in _Database._commit() could prevent this from working, so that a program trusting __del__() to get the on-disk files in synch could be badly surprised. The race has been repaired. A sync() method was also added so that shelve can guarantee data is written to disk. The close() method can now be called more than once without complaint. - The classes in threading.py are now new-style classes. That they weren't before was an oversight. - The urllib2 digest authentication handlers now define the correct auth_header. The earlier versions would fail at runtime. - SF bug 763023: fix uncaught ZeroDivisionError in difflib ratio methods when there are no lines. - SF bug 763637: fix exception in Tkinter with after_cancel which could occur with Tk 8.4 - SF bug 770601: CGIHTTPServer.py now passes the entire environment to child processes. - SF bug 765238: add filter to fnmatch's __all__. - SF bug 748201: make time.strptime() error messages more helpful. - SF patch 764470: Do not dump the args attribute of a Fault object in xmlrpclib. - SF patch 549151: urllib and urllib2 now redirect POSTs on 301 responses. - SF patch 766650: The whichdb module was fixed to recognize dbm files generated by gdbm on OS/2 EMX. - SF bugs 763047 and 763052: fixes bug of timezone value being left as -1 when ``time.tzname[0] == time.tzname[1] and not time.daylight`` is true when it should only when time.daylight is true. - SF bug 764548: re now allows subclasses of str and unicode to be used as patterns. - SF bug 763637: In Tkinter, change after_cancel() to handle tuples of varying sizes. Tk 8.4 returns a different number of values than Tk 8.3. - SF bug 763023: difflib.ratio() did not catch zero division. - The Queue module now has an __all__ attribute. Tools/Demos ----------- - See Lib/idlelib/NEWS.txt for IDLE news. - SF bug 753592: webchecker/wsgui now handles user supplied directories. - The trace.py script has been removed. It is now in the standard library. Build ----- - Python now compiles with -fno-strict-aliasing if possible (SF bug 766696). - The socket module compiles on IRIX 6.5.10. - An irix64 system is treated the same way as an irix6 system (SF patch 764560). - Several definitions were missing on FreeBSD 5.x unless the __BSD_VISIBLE symbol was defined. configure now defines it as needed. C API ----- - Unicode objects now support mbcs as a built-in encoding, so the C API can use it without deferring to the encodings package. Windows ------- - The Windows implementation of PyThread_start_new_thread() never checked error returns from Windows functions correctly. As a result, it could claim to start a new thread even when the Microsoft _beginthread() function failed (due to "too many threads" -- this is on the order of thousands when it happens). In these cases, the Python exception :: thread.error: can't start new thread is raised now. - SF bug 766669: Prevent a GPF on interpreter exit when sockets are in use. The interpreter now calls WSACleanup() from Py_Finalize() instead of from DLL teardown. Mac --- - Bundlebuilder now inherits default values in the right way. It was previously possible for app bundles to get a type of "BNDL" instead of "APPL." Other improvements include, a --build-id option to specify the CFBundleIdentifier and using the --python option to set the executable in the bundle. - Fixed two bugs in MacOSX framework handling. - pythonw did not allow user interaction in 2.3rc1, this has been fixed. - Python is now compiled with -mno-fused-madd, making all tests pass on Panther. What's New in Python 2.3 beta 2? ================================ *Release date: 29-Jun-2003* Core and builtins ----------------- - A program can now set the environment variable PYTHONINSPECT to some string value in Python, and cause the interpreter to enter the interactive prompt at program exit, as if Python had been invoked with the -i option. - list.index() now accepts optional start and stop arguments. Similar changes were made to UserList.index(). SF feature request 754014. - SF patch 751998 fixes an unwanted side effect of the previous fix for SF bug 742860 (the next item). - SF bug 742860: "WeakKeyDictionary __delitem__ uses iterkeys". This wasn't threadsafe, was very inefficient (expected time O(len(dict)) instead of O(1)), and could raise a spurious RuntimeError if another thread mutated the dict during __delitem__, or if a comparison function mutated it. It also neglected to raise KeyError when the key wasn't present; didn't raise TypeError when the key wasn't of a weakly referencable type; and broke various more-or-less obscure dict invariants by using a sequence of equality comparisons over the whole set of dict keys instead of computing the key's hash code to narrow the search to those keys with the same hash code. All of these are considered to be bugs. A new implementation of __delitem__ repairs all that, but note that fixing these bugs may change visible behavior in code relying (whether intentionally or accidentally) on old behavior. - SF bug 734869: Fixed a compiler bug that caused a fatal error when compiling a list comprehension that contained another list comprehension embedded in a lambda expression. - SF bug 705231: builtin pow() no longer lets the platform C pow() raise -1.0 to integer powers, because (at least) glibc gets it wrong in some cases. The result should be -1.0 if the power is odd and 1.0 if the power is even, and any float with a sufficiently large exponent is (mathematically) an exact even integer. - SF bug 759227: A new-style class that implements __nonzero__() must return a bool or int (but not an int subclass) from that method. This matches the restriction on classic classes. - The encoding attribute has been added for file objects, and set to the terminal encoding on Unix and Windows. - The softspace attribute of file objects became read-only by oversight. It's writable again. - Reverted a 2.3 beta 1 change to iterators for subclasses of list and tuple. By default, the iterators now access data elements directly instead of going through __getitem__. If __getitem__ access is preferred, then __iter__ can be overridden. - SF bug 735247: The staticmethod and super types participate in garbage collection. Before this change, it was possible for leaks to occur in functions with non-global free variables that used these types. Extension modules ----------------- - the socket module has a new exception, socket.timeout, to allow timeouts to be handled separately from other socket errors. - SF bug 751276: cPickle has fixed to propagate exceptions raised in user code. In earlier versions, cPickle caught and ignored any exception when it performed operations that it expected to raise specific exceptions like AttributeError. - cPickle Pickler and Unpickler objects now participate in garbage collection. - mimetools.choose_boundary() could return duplicate strings at times, especially likely on Windows. The strings returned are now guaranteed unique within a single program run. - thread.interrupt_main() raises KeyboardInterrupt in the main thread. dummy_thread has also been modified to try to simulate the behavior. - array.array.insert() now treats negative indices as being relative to the end of the array, just like list.insert() does. (SF bug #739313) - The datetime module classes datetime, time, and timedelta are now properly subclassable. - _tkinter.{get|set}busywaitinterval was added. - itertools.islice() now accepts stop=None as documented. Fixes SF bug #730685. - the bsddb185 module is built in one restricted instance - /usr/include/db.h exists and defines HASHVERSION to be 2. This is true for many BSD-derived systems. Library ------- - Some happy doctest extensions from Jim Fulton have been added to doctest.py. These are already being used in Zope3. The two primary ones: doctest.debug(module, name) extracts the doctests from the named object in the given module, puts them in a temp file, and starts pdb running on that file. This is great when a doctest fails. doctest.DocTestSuite(module=None) returns a synthesized unittest TestSuite instance, to be run by the unittest framework, which runs all the doctests in the module. This allows writing tests in doctest style (which can be clearer and shorter than writing tests in unittest style), without losing unittest's powerful testing framework features (which doctest lacks). - For compatibility with doctests created before 2.3, if an expected output block consists solely of "1" and the actual output block consists solely of "True", it's accepted as a match; similarly for "0" and "False". This is quite un-doctest-like, but is practical. The behavior can be disabled by passing the new doctest module constant DONT_ACCEPT_TRUE_FOR_1 to the new optionflags optional argument. - ZipFile.testzip() now only traps BadZipfile exceptions. Previously, a bare except caught to much and reported all errors as a problem in the archive. - The logging module now has a new function, makeLogRecord() making LogHandler easier to interact with DatagramHandler and SocketHandler. - The cgitb module has been extended to support plain text display (SF patch 569574). - A brand new version of IDLE (from the IDLEfork project at SourceForge) is now included as Lib/idlelib. The old Tools/idle is no more. - Added a new module: trace (documentation missing). This module used to be distributed in Tools/scripts. It uses sys.settrace() to trace code execution -- either function calls or individual lines. It can generate tracing output during execution or a post-mortem report of code coverage. - The threading module has new functions settrace() and setprofile() that cooperate with the functions of the same name in the sys module. A function registered with the threading module will be used for all threads it creates. The new trace module uses this to provide tracing for code running in threads. - copy.py: applied SF patch 707900, fixing bug 702858, by Steven Taschuk. Copying a new-style class that had a reference to itself didn't work. (The same thing worked fine for old-style classes.) Builtin functions are now treated as atomic, fixing bug #746304. - difflib.py has two new functions: context_diff() and unified_diff(). - More fixes to urllib (SF 549151): (a) When redirecting, always use GET. This is common practice and more-or-less sanctioned by the HTTP standard. (b) Add a handler for 307 redirection, which becomes an error for POST, but a regular redirect for GET and HEAD - Added optional 'onerror' argument to os.walk(), to control error handling. - inspect.is{method|data}descriptor was added, to allow pydoc display __doc__ of data descriptors. - Fixed socket speed loss caused by use of the _socketobject wrapper class in socket.py. - timeit.py now checks the current directory for imports. - urllib2.py now knows how to order proxy classes, so the user doesn't have to insert it in front of other classes, nor do dirty tricks like inserting a "dummy" HTTPHandler after a ProxyHandler when building an opener with proxy support. - Iterators have been added for dbm keys. - random.Random objects can now be pickled. Tools/Demos ----------- - pydoc now offers help on keywords and topics. - Tools/idle is gone; long live Lib/idlelib. - diff.py prints file diffs in context, unified, or ndiff formats, providing a command line interface to difflib.py. - texcheck.py is a new script for making a rough validation of Python LaTeX files. Build ----- - Setting DESTDIR during 'make install' now allows specifying a different root directory. C API ----- - PyType_Ready(): If a type declares that it participates in gc (Py_TPFLAGS_HAVE_GC), and its base class does not, and its base class's tp_free slot is the default _PyObject_Del, and type does not define a tp_free slot itself, _PyObject_GC_Del is assigned to type->tp_free. Previously _PyObject_Del was inherited, which could at best lead to a segfault. In addition, if even after this magic the type's tp_free slot is _PyObject_Del or NULL, and the type is a base type (Py_TPFLAGS_BASETYPE), TypeError is raised: since the type is a base type, its dealloc function must call type->tp_free, and since the type is gc'able, tp_free must not be NULL or _PyObject_Del. - PyThreadState_SetAsyncExc(): A new API (deliberately accessible only from C) to interrupt a thread by sending it an exception. It is intentional that you have to write your own C extension to call it from Python. New platforms ------------- None this time. Tests ----- - test_imp rewritten so that it doesn't raise RuntimeError if run as a side effect of being imported ("import test.autotest"). Windows ------- - The Windows installer ships with Tcl/Tk 8.4.3 (upgraded from 8.4.1). - The installer always suggested that Python be installed on the C: drive, due to a hardcoded "C:" generated by the Wise installation wizard. People with machines where C: is not the system drive usually want Python installed on whichever drive is their system drive instead. We removed the hardcoded "C:", and two testers on machines where C: is not the system drive report that the installer now suggests their system drive. Note that you can always select the directory you want in the "Select Destination Directory" dialog -- that's what it's for. Mac --- - There's a new module called "autoGIL", which offers a mechanism to automatically release the Global Interpreter Lock when an event loop goes to sleep, allowing other threads to run. It's currently only supported on OSX, in the Mach-O version. - The OSA modules now allow direct access to properties of the toplevel application class (in AppleScript terminology). - The Package Manager can now update itself. SourceForge Bugs and Patches Applied ------------------------------------ 430160, 471893, 501716, 542562, 549151, 569574, 595837, 596434, 598163, 604210, 604716, 610332, 612627, 614770, 620190, 621891, 622042, 639139, 640236, 644345, 649742, 649742, 658233, 660022, 661318, 661676, 662807, 662923, 666219, 672855, 678325, 682347, 683486, 684981, 685773, 686254, 692776, 692959, 693094, 696777, 697989, 700827, 703666, 708495, 708604, 708901, 710733, 711902, 713722, 715782, 718286, 719359, 719367, 723136, 723831, 723962, 724588, 724767, 724767, 725942, 726150, 726446, 726869, 727051, 727719, 727719, 727805, 728277, 728563, 728656, 729096, 729103, 729293, 729297, 729300, 729317, 729395, 729622, 729817, 730170, 730296, 730594, 730685, 730826, 730963, 731209, 731403, 731504, 731514, 731626, 731635, 731643, 731644, 731644, 731689, 732124, 732143, 732234, 732284, 732284, 732479, 732761, 732783, 732951, 733667, 733781, 734118, 734231, 734869, 735051, 735293, 735527, 735613, 735694, 736962, 736962, 737970, 738066, 739313, 740055, 740234, 740301, 741806, 742126, 742741, 742860, 742860, 742911, 744041, 744104, 744238, 744687, 744877, 745055, 745478, 745525, 745620, 746012, 746304, 746366, 746801, 746953, 747348, 747667, 747954, 748846, 748849, 748973, 748975, 749191, 749210, 749759, 749831, 749911, 750008, 750092, 750542, 750595, 751038, 751107, 751276, 751451, 751916, 751941, 751956, 751998, 752671, 753451, 753602, 753617, 753845, 753925, 754014, 754340, 754447, 755031, 755087, 755147, 755245, 755683, 755987, 756032, 756996, 757058, 757229, 757818, 757821, 757822, 758112, 758910, 759227, 759889, 760257, 760703, 760792, 761104, 761337, 761519, 761830, 762455 What's New in Python 2.3 beta 1? ================================ *Release date: 25-Apr-2003* Core and builtins ----------------- - New format codes B, H, I, k and K have been implemented for PyArg_ParseTuple and PyBuild_Value. - New builtin function sum(seq, start=0) returns the sum of all the items in iterable object seq, plus start (items are normally numbers, and cannot be strings). - bool() called without arguments now returns False rather than raising an exception. This is consistent with calling the constructors for the other builtin types -- called without argument they all return the false value of that type. (SF patch #724135) - In support of PEP 269 (making the pgen parser generator accessible from Python), some changes to the pgen code structure were made; a few files that used to be linked only with pgen are now linked with Python itself. - The repr() of a weakref object now shows the __name__ attribute of the referenced object, if it has one. - super() no longer ignores data descriptors, except __class__. See the thread started at http://mail.python.org/pipermail/python-dev/2003-April/034338.html - list.insert(i, x) now interprets negative i as it would be interpreted by slicing, so negative values count from the end of the list. This was the only place where such an interpretation was not placed on a list index. - range() now works even if the arguments are longs with magnitude larger than sys.maxint, as long as the total length of the sequence fits. E.g., range(2**100, 2**101, 2**100) is the following list: [1267650600228229401496703205376L]. (SF patch #707427.) - Some horridly obscure problems were fixed involving interaction between garbage collection and old-style classes with "ambitious" getattr hooks. If an old-style instance didn't have a __del__ method, but did have a __getattr__ hook, and the instance became reachable only from an unreachable cycle, and the hook resurrected or deleted unreachable objects when asked to resolve "__del__", anything up to a segfault could happen. That's been repaired. - dict.pop now takes an optional argument specifying a default value to return if the key is not in the dict. If a default is not given and the key is not found, a KeyError will still be raised. Parallel changes were made to UserDict.UserDict and UserDict.DictMixin. [SF patch #693753] (contributed by Michael Stone.) - sys.getfilesystemencoding() was added to expose Py_FileSystemDefaultEncoding. - New function sys.exc_clear() clears the current exception. This is rarely needed, but can sometimes be useful to release objects referenced by the traceback held in sys.exc_info()[2]. (SF patch #693195.) - On 64-bit systems, a dictionary could contain duplicate long/int keys if the key value was larger than 2**32. See SF bug #689659. - Fixed SF bug #663074. The codec system was using global static variables to store internal data. As a result, any attempts to use the unicode system with multiple active interpreters, or successive interpreter executions, would fail. - "%c" % u"a" now returns a unicode string instead of raising a TypeError. u"%c" % 0xffffffff now raises a OverflowError instead of a ValueError to be consistent with "%c" % 256. See SF patch #710127. Extension modules ----------------- - The socket module now provides the functions inet_pton and inet_ntop for converting between string and packed representation of IP addresses. There is also a new module variable, has_ipv6, which is True iff the current Python has IPv6 support. See SF patch #658327. - Tkinter wrappers around Tcl variables now pass objects directly to Tcl, instead of first converting them to strings. - The .*? pattern in the re module is now special-cased to avoid the recursion limit. (SF patch #720991 -- many thanks to Gary Herron and Greg Chapman.) - New function sys.call_tracing() allows pdb to debug code recursively. - New function gc.get_referents(obj) returns a list of objects directly referenced by obj. In effect, it exposes what the object's tp_traverse slot does, and can be helpful when debugging memory leaks. - The iconv module has been removed from this release. - The platform-independent routines for packing floats in IEEE formats (struct.pack's f, d codes; pickle and cPickle's protocol 1 pickling of floats) ignored that rounding can cause a carry to propagate. The worst consequence was that, in rare cases, f could produce strings that, when unpacked again, were a factor of 2 away from the original float. This has been fixed. See SF bug #705836. - New function time.tzset() provides access to the C library tzset() function, if supported. (SF patch #675422.) - Using createfilehandler, deletefilehandler, createtimerhandler functions on Tkinter.tkinter (_tkinter module) no longer crashes the interpreter. See SF bug #692416. - Modified the fcntl.ioctl() function to allow modification of a passed mutable buffer (for details see the reference documentation). - Made user requested changes to the itertools module. Subsumed the times() function into repeat(). Added chain() and cycle(). - The rotor module is now deprecated; the encryption algorithm it uses is not believed to be secure, and including crypto code with Python has implications for exporting and importing it in various countries. - The socket module now always uses the _socketobject wrapper class, even on platforms which have dup(2). The makefile() method is built directly on top of the socket without duplicating the file descriptor, allowing timeouts to work properly. Library ------- - New generator function os.walk() is an easy-to-use alternative to os.path.walk(). See os module docs for details. os.path.walk() isn't deprecated at this time, but may become deprecated in a future release. - Added new module "platform" which provides a wide range of tools for querying platform dependent features. - netrc now allows ASCII punctuation characters in passwords. - shelve now supports the optional writeback argument, and exposes pickle protocol versions. - Several methods of nntplib.NNTP have grown an optional file argument which specifies a file where to divert the command's output (already supported by the body() method). (SF patch #720468) - The self-documenting XML server library DocXMLRPCServer was added. - Support for internationalized domain names has been added through the 'idna' and 'punycode' encodings, the 'stringprep' module, the 'mkstringprep' tool, and enhancements to the socket and httplib modules. - htmlentitydefs has two new dictionaries: name2codepoint maps HTML entity names to Unicode codepoints (as integers). codepoint2name is the reverse mapping. See SF patch #722017. - pdb has a new command, "debug", which lets you step through arbitrary code from the debugger's (pdb) prompt. - unittest.failUnlessEqual and its equivalent unittest.assertEqual now return 'not a == b' rather than 'a != b'. This gives the desired result for classes that define __eq__ without defining __ne__. - sgmllib now supports SGML marked sections, in particular the MS Office extensions. - The urllib module now offers support for the iterator protocol. SF patch 698520 contributed by Brett Cannon. - New module timeit provides a simple framework for timing the execution speed of expressions and statements. - sets.Set objects now support mixed-type __eq__ and __ne__, instead of raising TypeError. If x is a Set object and y is a non-Set object, x == y is False, and x != y is True. This is akin to the change made for mixed-type comparisons of datetime objects in 2.3a2; more info about the rationale is in the NEWS entry for that. See also SF bug report . - On Unix platforms, if os.listdir() is called with a Unicode argument, it now returns Unicode strings. (This behavior was added earlier to the Windows NT/2k/XP version of os.listdir().) - Distutils: both 'py_modules' and 'packages' keywords can now be specified in core.setup(). Previously you could supply one or the other, but not both of them. (SF patch #695090 from Bernhard Herzog) - New csv package makes it easy to read/write CSV files. - Module shlex has been extended to allow posix-like shell parsings, including a split() function for easy spliting of quoted strings and commands. An iterator interface was also implemented. Tools/Demos ----------- - New script combinerefs.py helps analyze new PYTHONDUMPREFS output. See the module docstring for details. Build ----- - Fix problem building on OSF1 because the compiler only accepted preprocessor directives that start in column 1. (SF bug #691793.) C API ----- - Added PyGC_Collect(), equivalent to calling gc.collect(). - PyThreadState_GetDict() was changed not to raise an exception or issue a fatal error when no current thread state is available. This makes it possible to print dictionaries when no thread is active. - LONG_LONG was renamed to PY_LONG_LONG. Extensions that use this and need compatibility with previous versions can use this: #ifndef PY_LONG_LONG #define PY_LONG_LONG LONG_LONG #endif - Added PyObject_SelfIter() to fill the tp_iter slot for the typical case where the method returns its self argument. - The extended type structure used for heap types (new-style classes defined by Python code using a class statement) is now exported from object.h as PyHeapTypeObject. (SF patch #696193.) New platforms ------------- None this time. Tests ----- - test_timeout now requires -u network to be passed to regrtest to run. See SF bug #692988. Windows ------- - os.fsync() now exists on Windows, and calls the Microsoft _commit() function. - New function winsound.MessageBeep() wraps the Win32 API MessageBeep(). Mac --- - os.listdir() now returns Unicode strings on MacOS X when called with a Unicode argument. See the general news item under "Library". - A new method MacOS.WMAvailable() returns true if it is safe to access the window manager, false otherwise. - EasyDialogs dialogs are now movable-modal, and if the application is currently in the background they will ask to be moved to the foreground before displaying. - OSA Scripting support has improved a lot, and gensuitemodule.py can now be used by mere mortals. The documentation is now also more or less complete. - The IDE (in a framework build) now includes introductory documentation in Apple Help Viewer format. What's New in Python 2.3 alpha 2? ================================= *Release date: 19-Feb-2003* Core and builtins ----------------- - Negative positions returned from PEP 293 error callbacks are now treated as being relative to the end of the input string. Positions that are out of bounds raise an IndexError. - sys.path[0] (the directory from which the script is loaded) is now turned into an absolute pathname, unless it is the empty string. (SF patch #664376.) - Finally fixed the bug in compile() and exec where a string ending with an indented code block but no newline would raise SyntaxError. This would have been a four-line change in parsetok.c... Except codeop.py depends on this behavior, so a compilation flag had to be invented that causes the tokenizer to revert to the old behavior; this required extra changes to 2 .h files, 2 .c files, and 2 .py files. (Fixes SF bug #501622.) - If a new-style class defines neither __new__ nor __init__, its constructor would ignore all arguments. This is changed now: the constructor refuses arguments in this case. This might break code that worked under Python 2.2. The simplest fix is to add a no-op __init__: ``def __init__(self, *args, **kw): pass``. - Through a bytecode optimizer bug (and I bet you didn't even know Python *had* a bytecode optimizer :-), "unsigned" hex/oct constants with a leading minus sign would come out with the wrong sign. ("Unsigned" hex/oct constants are those with a face value in the range sys.maxint+1 through sys.maxint*2+1, inclusive; these have always been interpreted as negative numbers through sign folding.) E.g. 0xffffffff is -1, and -(0xffffffff) is 1, but -0xffffffff would come out as -4294967295. This was the case in Python 2.2 through 2.2.2 and 2.3a1, and in Python 2.4 it will once again have that value, but according to PEP 237 it really needs to be 1 now. This will be backported to Python 2.2.3 a well. (SF #660455) - int(s, base) sometimes sign-folds hex and oct constants; it only does this when base is 0 and s.strip() starts with a '0'. When the sign is actually folded, as in int("0xffffffff", 0) on a 32-bit machine, which returns -1, a FutureWarning is now issued; in Python 2.4, this will return 4294967295L, as do int("+0xffffffff", 0) and int("0xffffffff", 16) right now. (PEP 347) - super(X, x): x may now be a proxy for an X instance, i.e. issubclass(x.__class__, X) but not issubclass(type(x), X). - isinstance(x, X): if X is a new-style class, this is now equivalent to issubclass(type(x), X) or issubclass(x.__class__, X). Previously only type(x) was tested. (For classic classes this was already the case.) - compile(), eval() and the exec statement now fully support source code passed as unicode strings. - int subclasses can be initialized with longs if the value fits in an int. See SF bug #683467. - long(string, base) takes time linear in len(string) when base is a power of 2 now. It used to take time quadratic in len(string). - filter returns now Unicode results for Unicode arguments. - raw_input can now return Unicode objects. - List objects' sort() method now accepts None as the comparison function. Passing None is semantically identical to calling sort() with no arguments. - Fixed crash when printing a subclass of str and __str__ returned self. See SF bug #667147. - Fixed an invalid RuntimeWarning and an undetected error when trying to convert a long integer into a float which couldn't fit. See SF bug #676155. - Function objects now have a __module__ attribute that is bound to the name of the module in which the function was defined. This applies for C functions and methods as well as functions and methods defined in Python. This attribute is used by pickle.whichmodule(), which changes the behavior of whichmodule slightly. In Python 2.2 whichmodule() returns "__main__" for functions that are not defined at the top-level of a module (examples: methods, nested functions). Now whichmodule() will return the proper module name. Extension modules ----------------- - operator.isNumberType() now checks that the object has a nb_int or nb_float slot, rather than simply checking whether it has a non-NULL tp_as_number pointer. - The imp module now has ways to acquire and release the "import lock": imp.acquire_lock() and imp.release_lock(). Note: this is a reentrant lock, so releasing the lock only truly releases it when this is the last release_lock() call. You can check with imp.lock_held(). (SF bug #580952 and patch #683257.) - Change to cPickle to match pickle.py (see below and PEP 307). - Fix some bugs in the parser module. SF bug #678518. - Thanks to Scott David Daniels, a subtle bug in how the zlib extension implemented flush() was fixed. Scott also rewrote the zlib test suite using the unittest module. (SF bug #640230 and patch #678531.) - Added an itertools module containing high speed, memory efficient looping constructs inspired by tools from Haskell and SML. - The SSL module now handles sockets with a timeout set correctly (SF patch #675750, fixing SF bug #675552). - os/posixmodule has grown the sysexits.h constants (EX_OK and friends). - Fixed broken threadstate swap in readline that could cause fatal errors when a readline hook was being invoked while a background thread was active. (SF bugs #660476 and #513033.) - fcntl now exposes the strops.h I_* constants. - Fix a crash on Solaris that occurred when calling close() on an mmap'ed file which was already closed. (SF patch #665913) - Fixed several serious bugs in the zipimport implementation. - datetime changes: The date class is now properly subclassable. (SF bug #720908) The datetime and datetimetz classes have been collapsed into a single datetime class, and likewise the time and timetz classes into a single time class. Previously, a datetimetz object with tzinfo=None acted exactly like a datetime object, and similarly for timetz. This wasn't enough of a difference to justify distinct classes, and life is simpler now. today() and now() now round system timestamps to the closest microsecond . This repairs an irritation most likely seen on Windows systems. In dt.astimezone(tz), if tz.utcoffset(dt) returns a duration, ValueError is raised if tz.dst(dt) returns None (2.3a1 treated it as 0 instead, but a tzinfo subclass wishing to participate in time zone conversion has to take a stand on whether it supports DST; if you don't care about DST, then code dst() to return 0 minutes, meaning that DST is never in effect). The tzinfo methods utcoffset() and dst() must return a timedelta object (or None) now. In 2.3a1 they could also return an int or long, but that was an unhelpfully redundant leftover from an earlier version wherein they couldn't return a timedelta. TOOWTDI. The example tzinfo class for local time had a bug. It was replaced by a later example coded by Guido. datetime.astimezone(tz) no longer raises an exception when the input datetime has no UTC equivalent in tz. For typical "hybrid" time zones (a single tzinfo subclass modeling both standard and daylight time), this case can arise one hour per year, at the hour daylight time ends. See new docs for details. In short, the new behavior mimics the local wall clock's behavior of repeating an hour in local time. dt.astimezone() can no longer be used to convert between naive and aware datetime objects. If you merely want to attach, or remove, a tzinfo object, without any conversion of date and time members, use dt.replace(tzinfo=whatever) instead, where "whatever" is None or a tzinfo subclass instance. A new method tzinfo.fromutc(dt) can be overridden in tzinfo subclasses to give complete control over how a UTC time is to be converted to a local time. The default astimezone() implementation calls fromutc() as its last step, so a tzinfo subclass can affect that too by overriding fromutc(). It's expected that the default fromutc() implementation will be suitable as-is for "almost all" time zone subclasses, but the creativity of political time zone fiddling appears unbounded -- fromutc() allows the highly motivated to emulate any scheme expressible in Python. datetime.now(): The optional tzinfo argument was undocumented (that's repaired), and its name was changed to tz ("tzinfo" is overloaded enough already). With a tz argument, now(tz) used to return the local date and time, and attach tz to it, without any conversion of date and time members. This was less than useful. Now now(tz) returns the current date and time as local time in tz's time zone, akin to :: tz.fromutc(datetime.utcnow().replace(tzinfo=utc)) where "utc" is an instance of a tzinfo subclass modeling UTC. Without a tz argument, now() continues to return the current local date and time, as a naive datetime object. datetime.fromtimestamp(): Like datetime.now() above, this had less than useful behavior when the optional tinzo argument was specified. See also SF bug report . date and datetime comparison: In order to prevent comparison from falling back to the default compare-object-addresses strategy, these raised TypeError whenever they didn't understand the other object type. They still do, except when the other object has a "timetuple" attribute, in which case they return NotImplemented now. This gives other datetime objects (e.g., mxDateTime) a chance to intercept the comparison. date, time, datetime and timedelta comparison: When the exception for mixed-type comparisons in the last paragraph doesn't apply, if the comparison is == then False is returned, and if the comparison is != then True is returned. Because dict lookup and the "in" operator only invoke __eq__, this allows, for example, :: if some_datetime in some_sequence: and :: some_dict[some_timedelta] = whatever to work as expected, without raising TypeError just because the sequence is heterogeneous, or the dict has mixed-type keys. [This seems like a good idea to implement for all mixed-type comparisons that don't want to allow falling back to address comparison.] The constructors building a datetime from a timestamp could raise ValueError if the platform C localtime()/gmtime() inserted "leap seconds". Leap seconds are ignored now. On such platforms, it's possible to have timestamps that differ by a second, yet where datetimes constructed from them are equal. The pickle format of date, time and datetime objects has changed completely. The undocumented pickler and unpickler functions no longer exist. The undocumented __setstate__() and __getstate__() methods no longer exist either. Library ------- - The logging module was updated slightly; the WARN level was renamed to WARNING, and the matching function/method warn() to warning(). - The pickle and cPickle modules were updated with a new pickling protocol (documented by pickletools.py, see below) and several extensions to the pickle customization API (__reduce__, __setstate__ etc.). The copy module now uses more of the pickle customization API to copy objects that don't implement __copy__ or __deepcopy__. See PEP 307 for details. - The distutils "register" command now uses http://www.python.org/pypi as the default repository. (See PEP 301.) - the platform dependent path related variables sep, altsep, extsep, pathsep, curdir, pardir and defpath are now defined in the platform dependent path modules (e.g. ntpath.py) rather than os.py, so these variables are now available via os.path. They continue to be available from the os module. (see ). - array.array was added to the types repr.py knows about (see ). - The new pickletools.py contains lots of documentation about pickle internals, and supplies some helpers for working with pickles, such as a symbolic pickle disassembler. - Xmlrpclib.py now supports the builtin boolean type. - py_compile has a new 'doraise' flag and a new PyCompileError exception. - SimpleXMLRPCServer now supports CGI through the CGIXMLRPCRequestHandler class. - The sets module now raises TypeError in __cmp__, to clarify that sets are not intended to be three-way-compared; the comparison operators are overloaded as subset/superset tests. - Bastion.py and rexec.py are disabled. These modules are not safe in Python 2.2. or 2.3. - realpath is now exported when doing ``from poxixpath import *``. It is also exported for ntpath, macpath, and os2emxpath. See SF bug #659228. - New module tarfile from Lars Gustäbel provides a comprehensive interface to tar archive files with transparent gzip and bzip2 compression. See SF patch #651082. - urlparse can now parse imap:// URLs. See SF feature request #618024. - Tkinter.Canvas.scan_dragto() provides an optional parameter to support the gain value which is passed to Tk. SF bug# 602259. - Fix logging.handlers.SysLogHandler protocol when using UNIX domain sockets. See SF patch #642974. - The dospath module was deleted. Use the ntpath module when manipulating DOS paths from other platforms. Tools/Demos ----------- - Two new scripts (db2pickle.py and pickle2db.py) were added to the Tools/scripts directory to facilitate conversion from the old bsddb module to the new one. While the user-visible API of the new module is compatible with the old one, it's likely that the version of the underlying database library has changed. To convert from the old library, run the db2pickle.py script using the old version of Python to convert it to a pickle file. After upgrading Python, run the pickle2db.py script using the new version of Python to reconstitute your database. For example: % python2.2 db2pickle.py -h some.db > some.pickle % python2.3 pickle2db.py -h some.db.new < some.pickle Run the scripts without any args to get a usage message. Build ----- - The audio driver tests (test_ossaudiodev.py and test_linuxaudiodev.py) are no longer run by default. This is because they don't always work, depending on your hardware and software. To run these tests, you must use an invocation like :: ./python Lib/test/regrtest.py -u audio test_ossaudiodev - On systems which build using the configure script, compiler flags which used to be lumped together using the OPT flag have been split into two groups, OPT and BASECFLAGS. OPT is meant to carry just optimization- and debug-related flags like "-g" and "-O3". BASECFLAGS is meant to carry compiler flags that are required to get a clean compile. On some platforms (many Linux flavors in particular) BASECFLAGS will be empty by default. On others, such as Mac OS X and SCO, it will contain required flags. This change allows people building Python to override OPT without fear of clobbering compiler flags which are required to get a clean build. - On Darwin/Mac OS X platforms, /sw/lib and /sw/include are added to the relevant search lists in setup.py. This allows users building Python to take advantage of the many packages available from the fink project . - A new Makefile target, scriptsinstall, installs a number of useful scripts from the Tools/scripts directory. C API ----- - PyEval_GetFrame() is now declared to return a ``PyFrameObject *`` instead of a plain ``PyObject *``. (SF patch #686601.) - PyNumber_Check() now checks that the object has a nb_int or nb_float slot, rather than simply checking whether it has a non-NULL tp_as_number pointer. - A C type that inherits from a base type that defines tp_as_buffer will now inherit the tp_as_buffer pointer if it doesn't define one. (SF #681367) - The PyArg_Parse functions now issue a DeprecationWarning if a float argument is provided when an integer is specified (this affects the 'b', 'B', 'h', 'H', 'i', and 'l' codes). Future versions of Python will raise a TypeError. Tests ----- - Several tests weren't being run from regrtest.py (test_timeout.py, test_tarfile.py, test_netrc.py, test_multifile.py, test_importhooks.py and test_imp.py). Now they are. (Note to developers: please read Lib/test/README when creating a new test, to make sure to do it right! All tests need to use either unittest or pydoc.) - Added test_posix.py, a test suite for the posix module. - Added test_hexoct.py, a test suite for hex/oct constant folding. Windows ------- - The timeout code for socket connect() didn't work right; this has now been fixed. test_timeout.py should pass (at least most of the time). - distutils' msvccompiler class now passes the preprocessor options to the resource compiler. See SF patch #669198. - The bsddb module now ships with Sleepycat's 4.1.25.NC, the latest release without strong cryptography. - sys.path[0], if it contains a directory name, is now always an absolute pathname. (SF patch #664376.) - The new logging package is now installed by the Windows installer. It wasn't in 2.3a1 due to oversight. Mac --- - There are new dialogs EasyDialogs.AskFileForOpen, AskFileForSave and AskFolder. The old macfs.StandardGetFile and friends are deprecated. - Most of the standard library now uses pathnames or FSRefs in preference of FSSpecs, and use the underlying Carbon.File and Carbon.Folder modules in stead of macfs. macfs will probably be deprecated in the future. - Type Carbon.File.FSCatalogInfo and supporting methods have been implemented. This also makes macfs.FSSpec.SetDates() work again. - There is a new module pimp, the package install manager for Python, and accompanying applet PackageManager. These allow you to easily download and install pretested extension packages either in source or binary form. Only in MacPython-OSX. - Applets are now built with bundlebuilder in MacPython-OSX, which should make them more robust and also provides a path towards BuildApplication. The downside of this change is that applets can no longer be run from the Terminal window, this will hopefully be fixed in the 2.3b1. What's New in Python 2.3 alpha 1? ================================= *Release date: 31-Dec-2002* Type/class unification and new-style classes -------------------------------------------- - One can now assign to __bases__ and __name__ of new-style classes. - dict() now accepts keyword arguments so that dict(one=1, two=2) is the equivalent of {"one": 1, "two": 2}. Accordingly, the existing (but undocumented) 'items' keyword argument has been eliminated. This means that dict(items=someMapping) now has a different meaning than before. - int() now returns a long object if the argument is outside the integer range, so int("4" * 1000), int(1e200) and int(1L<<1000) will all return long objects instead of raising an OverflowError. - Assignment to __class__ is disallowed if either the old or the new class is a statically allocated type object (such as defined by an extension module). This prevents anomalies like 2.__class__ = bool. - New-style object creation and deallocation have been sped up significantly; they are now faster than classic instance creation and deallocation. - The __slots__ variable can now mention "private" names, and the right thing will happen (e.g. __slots__ = ["__foo"]). - The built-ins slice() and buffer() are now callable types. The types classobj (formerly class), code, function, instance, and instancemethod (formerly instance-method), which have no built-in names but are accessible through the types module, are now also callable. The type dict-proxy is renamed to dictproxy. - Cycles going through the __class__ link of a new-style instance are now detected by the garbage collector. - Classes using __slots__ are now properly garbage collected. [SF bug 519621] - Tightened the __slots__ rules: a slot name must be a valid Python identifier. - The constructor for the module type now requires a name argument and takes an optional docstring argument. Previously, this constructor ignored its arguments. As a consequence, deriving a class from a module (not from the module type) is now illegal; previously this created an unnamed module, just like invoking the module type did. [SF bug 563060] - A new type object, 'basestring', is added. This is a common base type for 'str' and 'unicode', and can be used instead of types.StringTypes, e.g. to test whether something is "a string": isinstance(x, basestring) is True for Unicode and 8-bit strings. This is an abstract base class and cannot be instantiated directly. - Changed new-style class instantiation so that when C's __new__ method returns something that's not a C instance, its __init__ is not called. [SF bug #537450] - Fixed super() to work correctly with class methods. [SF bug #535444] - If you try to pickle an instance of a class that has __slots__ but doesn't define or override __getstate__, a TypeError is now raised. This is done by adding a bozo __getstate__ to the class that always raises TypeError. (Before, this would appear to be pickled, but the state of the slots would be lost.) Core and builtins ----------------- - Import from zipfiles is now supported. The name of a zipfile placed on sys.path causes the import statement to look for importable Python modules (with .py, pyc and .pyo extensions) and packages inside the zipfile. The zipfile import follows the specification (though not the sample implementation) of PEP 273. The semantics of __path__ are compatible with those that have been implemented in Jython since Jython 2.1. - PEP 302 has been accepted. Although it was initially developed to support zipimport, it offers a new, general import hook mechanism. Several new variables have been added to the sys module: sys.meta_path, sys.path_hooks, and sys.path_importer_cache; these make extending the import statement much more convenient than overriding the __import__ built-in function. For a description of these, see PEP 302. - A frame object's f_lineno attribute can now be written to from a trace function to change which line will execute next. A command to exploit this from pdb has been added. [SF patch #643835] - The _codecs support module for codecs.py was turned into a builtin module to assure that at least the builtin codecs are available to the Python parser for source code decoding according to PEP 263. - issubclass now supports a tuple as the second argument, just like isinstance does. ``issubclass(X, (A, B))`` is equivalent to ``issubclass(X, A) or issubclass(X, B)``. - Thanks to Armin Rigo, the last known way to provoke a system crash by cleverly arranging for a comparison function to mutate a list during a list.sort() operation has been fixed. The effect of attempting to mutate a list, or even to inspect its contents or length, while a sort is in progress, is not defined by the language. The C implementation of Python 2.3 attempts to detect mutations, and raise ValueError if one occurs, but there's no guarantee that all mutations will be caught, or that any will be caught across releases or implementations. - Unicode file name processing for Windows (PEP 277) is implemented. All platforms now have an os.path.supports_unicode_filenames attribute, which is set to True on Windows NT/2000/XP, and False elsewhere. - Codec error handling callbacks (PEP 293) are implemented. Error handling in unicode.encode or str.decode can now be customized. - A subtle change to the semantics of the built-in function intern(): interned strings are no longer immortal. You must keep a reference to the return value intern() around to get the benefit. - Use of 'None' as a variable, argument or attribute name now issues a SyntaxWarning. In the future, None may become a keyword. - SET_LINENO is gone. co_lnotab is now consulted to determine when to call the trace function. C code that accessed f_lineno should call PyCode_Addr2Line instead (f_lineno is still there, but only kept up to date when there is a trace function set). - There's a new warning category, FutureWarning. This is used to warn about a number of situations where the value or sign of an integer result will change in Python 2.4 as a result of PEP 237 (integer unification). The warnings implement stage B0 mentioned in that PEP. The warnings are about the following situations: - Octal and hex literals without 'L' prefix in the inclusive range [0x80000000..0xffffffff]; these are currently negative ints, but in Python 2.4 they will be positive longs with the same bit pattern. - Left shifts on integer values that cause the outcome to lose bits or have a different sign than the left operand. To be precise: x< -*-" in the first or second line of a Python source file indicates the encoding. - list.sort() has a new implementation. While cross-platform results may vary, and in data-dependent ways, this is much faster on many kinds of partially ordered lists than the previous implementation, and reported to be just as fast on randomly ordered lists on several major platforms. This sort is also stable (if A==B and A precedes B in the list at the start, A precedes B after the sort too), although the language definition does not guarantee stability. A potential drawback is that list.sort() may require temp space of len(list)*2 bytes (``*4`` on a 64-bit machine). It's therefore possible for list.sort() to raise MemoryError now, even if a comparison function does not. See for full details. - All standard iterators now ensure that, once StopIteration has been raised, all future calls to next() on the same iterator will also raise StopIteration. There used to be various counterexamples to this behavior, which could caused confusion or subtle program breakage, without any benefits. (Note that this is still an iterator's responsibility; the iterator framework does not enforce this.) - Ctrl+C handling on Windows has been made more consistent with other platforms. KeyboardInterrupt can now reliably be caught, and Ctrl+C at an interactive prompt no longer terminates the process under NT/2k/XP (it never did under Win9x). Ctrl+C will interrupt time.sleep() in the main thread, and any child processes created via the popen family (on win2k; we can't make win9x work reliably) are also interrupted (as generally happens on for Linux/Unix.) [SF bugs 231273, 439992 and 581232] - sys.getwindowsversion() has been added on Windows. This returns a tuple with information about the version of Windows currently running. - Slices and repetitions of buffer objects now consistently return a string. Formerly, strings would be returned most of the time, but a buffer object would be returned when the repetition count was one or when the slice range was all inclusive. - Unicode objects in sys.path are no longer ignored but treated as directory names. - Fixed string.startswith and string.endswith builtin methods so they accept negative indices. [SF bug 493951] - Fixed a bug with a continue inside a try block and a yield in the finally clause. [SF bug 567538] - Most builtin sequences now support "extended slices", i.e. slices with a third "stride" parameter. For example, "hello world"[::-1] gives "dlrow olleh". - A new warning PendingDeprecationWarning was added to provide direction on features which are in the process of being deprecated. The warning will not be printed by default. To see the pending deprecations, use -Walways::PendingDeprecationWarning:: as a command line option or warnings.filterwarnings() in code. - Deprecated features of xrange objects have been removed as promised. The start, stop, and step attributes and the tolist() method no longer exist. xrange repetition and slicing have been removed. - New builtin function enumerate(x), from PEP 279. Example: enumerate("abc") is an iterator returning (0,"a"), (1,"b"), (2,"c"). The argument can be an arbitrary iterable object. - The assert statement no longer tests __debug__ at runtime. This means that assert statements cannot be disabled by assigning a false value to __debug__. - A method zfill() was added to str and unicode, that fills a numeric string to the left with zeros. For example, "+123".zfill(6) -> "+00123". - Complex numbers supported divmod() and the // and % operators, but these make no sense. Since this was documented, they're being deprecated now. - String and unicode methods lstrip(), rstrip() and strip() now take an optional argument that specifies the characters to strip. For example, "Foo!!!?!?!?".rstrip("?!") -> "Foo". - There's a new dictionary constructor (a class method of the dict class), dict.fromkeys(iterable, value=None). It constructs a dictionary with keys taken from the iterable and all values set to a single value. It can be used for building sets and for removing duplicates from sequences. - Added a new dict method pop(key). This removes and returns the value corresponding to key. [SF patch #539949] - A new built-in type, bool, has been added, as well as built-in names for its two values, True and False. Comparisons and sundry other operations that return a truth value have been changed to return a bool instead. Read PEP 285 for an explanation of why this is backward compatible. - Fixed two bugs reported as SF #535905: under certain conditions, deallocating a deeply nested structure could cause a segfault in the garbage collector, due to interaction with the "trashcan" code; access to the current frame during destruction of a local variable could access a pointer to freed memory. - The optional object allocator ("pymalloc") has been enabled by default. The recommended practice for memory allocation and deallocation has been streamlined. A header file is included, Misc/pymemcompat.h, which can be bundled with 3rd party extensions and lets them use the same API with Python versions from 1.5.2 onwards. - PyErr_Display will provide file and line information for all exceptions that have an attribute print_file_and_line, not just SyntaxErrors. - The UTF-8 codec will now encode and decode Unicode surrogates correctly and without raising exceptions for unpaired ones. - Universal newlines (PEP 278) is implemented. Briefly, using 'U' instead of 'r' when opening a text file for reading changes the line ending convention so that any of '\r', '\r\n', and '\n' is recognized (even mixed in one file); all three are converted to '\n', the standard Python line end character. - file.xreadlines() now raises a ValueError if the file is closed: Previously, an xreadlines object was returned which would raise a ValueError when the xreadlines.next() method was called. - sys.exit() inadvertently allowed more than one argument. An exception will now be raised if more than one argument is used. - Changed evaluation order of dictionary literals to conform to the general left to right evaluation order rule. Now {f1(): f2()} will evaluate f1 first. - Fixed bug #521782: when a file was in non-blocking mode, file.read() could silently lose data or wrongly throw an unknown error. - The sq_repeat, sq_inplace_repeat, sq_concat and sq_inplace_concat slots are now always tried after trying the corresponding nb_* slots. This fixes a number of minor bugs (see bug #624807). - Fix problem with dynamic loading on 64-bit AIX (see bug #639945). Extension modules ----------------- - Added three operators to the operator module: operator.pow(a,b) which is equivalent to: a**b. operator.is_(a,b) which is equivalent to: a is b. operator.is_not(a,b) which is equivalent to: a is not b. - posix.openpty now works on all systems that have /dev/ptmx. - A module zipimport exists to support importing code from zip archives. - The new datetime module supplies classes for manipulating dates and times. The basic design came from the Zope "fishbowl process", and favors practical commercial applications over calendar esoterica. See http://www.zope.org/Members/fdrake/DateTimeWiki/FrontPage - _tkinter now returns Tcl objects, instead of strings. Objects which have Python equivalents are converted to Python objects, other objects are wrapped. This can be configured through the wantobjects method, or Tkinter.wantobjects. - The PyBSDDB wrapper around the Sleepycat Berkeley DB library has been added as the package bsddb. The traditional bsddb module is still available in source code, but not built automatically anymore, and is now named bsddb185. This supports Berkeley DB versions from 3.0 to 4.1. For help converting your databases from the old module (which probably used an obsolete version of Berkeley DB) to the new module, see the db2pickle.py and pickle2db.py scripts described in the Tools/Demos section above. - unicodedata was updated to Unicode 3.2. It supports normalization and names for Hangul syllables and CJK unified ideographs. - resource.getrlimit() now returns longs instead of ints. - readline now dynamically adjusts its input/output stream if sys.stdin/stdout changes. - The _tkinter module (and hence Tkinter) has dropped support for Tcl/Tk 8.0 and 8.1. Only Tcl/Tk versions 8.2, 8.3 and 8.4 are supported. - cPickle.BadPickleGet is now a class. - The time stamps in os.stat_result are floating point numbers after stat_float_times has been called. - If the size passed to mmap.mmap() is larger than the length of the file on non-Windows platforms, a ValueError is raised. [SF bug 585792] - The xreadlines module is slated for obsolescence. - The strptime function in the time module is now always available (a Python implementation is used when the C library doesn't define it). - The 'new' module is no longer an extension, but a Python module that only exists for backwards compatibility. Its contents are no longer functions but callable type objects. - The bsddb.*open functions can now take 'None' as a filename. This will create a temporary in-memory bsddb that won't be written to disk. - posix.getloadavg, posix.lchown, posix.killpg, posix.mknod, and posix.getpgid have been added where available. - The locale module now exposes the C library's gettext interface. It also has a new function getpreferredencoding. - A security hole ("double free") was found in zlib-1.1.3, a popular third party compression library used by some Python modules. The hole was quickly plugged in zlib-1.1.4, and the Windows build of Python now ships with zlib-1.1.4. - pwd, grp, and resource return enhanced tuples now, with symbolic field names. - array.array is now a type object. A new format character 'u' indicates Py_UNICODE arrays. For those, .tounicode and .fromunicode methods are available. Arrays now support __iadd__ and __imul__. - dl now builds on every system that has dlfcn.h. Failure in case of sizeof(int)!=sizeof(long)!=sizeof(void*) is delayed until dl.open is called. - The sys module acquired a new attribute, api_version, which evaluates to the value of the PYTHON_API_VERSION macro with which the interpreter was compiled. - Fixed bug #470582: sre module would return a tuple (None, 'a', 'ab') when applying the regular expression '^((a)c)?(ab)$' on 'ab'. It now returns (None, None, 'ab'), as expected. Also fixed handling of lastindex/lastgroup match attributes in similar cases. For example, when running the expression r'(a)(b)?b' over 'ab', lastindex must be 1, not 2. - Fixed bug #581080: sre scanner was not checking the buffer limit before increasing the current pointer. This was creating an infinite loop in the search function, once the pointer exceeded the buffer limit. - The os.fdopen function now enforces a file mode starting with the letter 'r', 'w' or 'a', otherwise a ValueError is raised. This fixes bug #623464. - The linuxaudiodev module is now deprecated; it is being replaced by ossaudiodev. The interface has been extended to cover a lot more of OSS (see www.opensound.com), including most DSP ioctls and the OSS mixer API. Documentation forthcoming in 2.3a2. Library ------- - imaplib.py now supports SSL (Tino Lange and Piers Lauder). - Freeze's modulefinder.py has been moved to the standard library; slightly improved so it will issue less false missing submodule reports (see sf path #643711 for details). Documentation will follow with Python 2.3a2. - os.path exposes getctime. - unittest.py now has two additional methods called assertAlmostEqual() and failIfAlmostEqual(). They implement an approximate comparison by rounding the difference between the two arguments and comparing the result to zero. Approximate comparison is essential for unit tests of floating point results. - calendar.py now depends on the new datetime module rather than the time module. As a result, the range of allowable dates has been increased. - pdb has a new 'j(ump)' command to select the next line to be executed. - The distutils created windows installers now can run a postinstallation script. - doctest.testmod can now be called without argument, which means to test the current module. - When canceling a server that implemented threading with a keyboard interrupt, the server would shut down but not terminate (waiting on client threads). A new member variable, daemon_threads, was added to the ThreadingMixIn class in SocketServer.py to make it explicit that this behavior needs to be controlled. - A new module, optparse, provides a fancy alternative to getopt for command line parsing. It is a slightly modified version of Greg Ward's Optik package. - UserDict.py now defines a DictMixin class which defines all dictionary methods for classes that already have a minimum mapping interface. This greatly simplifies writing classes that need to be substitutable for dictionaries (such as the shelve module). - shelve.py now subclasses from UserDict.DictMixin. Now shelve supports all dictionary methods. This eases the transition to persistent storage for scripts originally written with dictionaries in mind. - shelve.open and the various classes in shelve.py now accept an optional binary flag, which defaults to False. If True, the values stored in the shelf are binary pickles. - A new package, logging, implements the logging API defined by PEP 282. The code is written by Vinay Sajip. - StreamReader, StreamReaderWriter and StreamRecoder in the codecs modules are iterators now. - gzip.py now handles files exceeding 2GB. Files over 4GB also work now (provided the OS supports it, and Python is configured with large file support), but in that case the underlying gzip file format can record only the least-significant 32 bits of the file size, so that some tools working with gzipped files may report an incorrect file size. - xml.sax.saxutils.unescape has been added, to replace entity references with their entity value. - Queue.Queue.{put,get} now support an optional timeout argument. - Various features of Tk 8.4 are exposed in Tkinter.py. The multiple option of tkFileDialog is exposed as function askopenfile{,name}s. - Various configure methods of Tkinter have been stream-lined, so that tag_configure, image_configure, window_configure now return a dictionary when invoked with no argument. - Importing the readline module now no longer has the side effect of calling setlocale(LC_CTYPE, ""). The initial "C" locale, or whatever locale is explicitly set by the user, is preserved. If you want repr() of 8-bit strings in your preferred encoding to preserve all printable characters of that encoding, you have to add the following code to your $PYTHONSTARTUP file or to your application's main(): import locale locale.setlocale(locale.LC_CTYPE, "") - shutil.move was added. shutil.copytree now reports errors as an exception at the end, instead of printing error messages. - Encoding name normalization was generalized to not only replace hyphens with underscores, but also all other non-alphanumeric characters (with the exception of the dot which is used for Python package names during lookup). The aliases.py mapping was updated to the new standard. - mimetypes has two new functions: guess_all_extensions() which returns a list of all known extensions for a mime type, and add_type() which adds one mapping between a mime type and an extension to the database. - New module: sets, defines the class Set that implements a mutable set type using the keys of a dict to represent the set. There's also a class ImmutableSet which is useful when you need sets of sets or when you need to use sets as dict keys, and a class BaseSet which is the base class of the two. - Added random.sample(population,k) for random sampling without replacement. Returns a k length list of unique elements chosen from the population. - random.randrange(-sys.maxint-1, sys.maxint) no longer raises OverflowError. That is, it now accepts any combination of 'start' and 'stop' arguments so long as each is in the range of Python's bounded integers. - Thanks to Raymond Hettinger, random.random() now uses a new core generator. The Mersenne Twister algorithm is implemented in C, threadsafe, faster than the previous generator, has an astronomically large period (2**19937-1), creates random floats to full 53-bit precision, and may be the most widely tested random number generator in existence. The random.jumpahead(n) method has different semantics for the new generator. Instead of jumping n steps ahead, it uses n and the existing state to create a new state. This means that jumpahead() continues to support multi-threaded code needing generators of non-overlapping sequences. However, it will break code which relies on jumpahead moving a specific number of steps forward. The attributes random.whseed and random.__whseed have no meaning for the new generator. Code using these attributes should switch to a new class, random.WichmannHill which is provided for backward compatibility and to make an alternate generator available. - New "algorithms" module: heapq, implements a heap queue. Thanks to Kevin O'Connor for the code and François Pinard for an entertaining write-up explaining the theory and practical uses of heaps. - New encoding for the Palm OS character set: palmos. - binascii.crc32() and the zipfile module had problems on some 64-bit platforms. These have been fixed. On a platform with 8-byte C longs, crc32() now returns a signed-extended 4-byte result, so that its value as a Python int is equal to the value computed a 32-bit platform. - xml.dom.minidom.toxml and toprettyxml now take an optional encoding argument. - Some fixes in the copy module: when an object is copied through its __reduce__ method, there was no check for a __setstate__ method on the result [SF patch 565085]; deepcopy should treat instances of custom metaclasses the same way it treats instances of type 'type' [SF patch 560794]. - Sockets now support timeout mode. After s.settimeout(T), where T is a float expressing seconds, subsequent operations raise an exception if they cannot be completed within T seconds. To disable timeout mode, use s.settimeout(None). There's also a module function, socket.setdefaulttimeout(T), which sets the default for all sockets created henceforth. - getopt.gnu_getopt was added. This supports GNU-style option processing, where options can be mixed with non-option arguments. - Stop using strings for exceptions. String objects used for exceptions are now classes deriving from Exception. The objects changed were: Tkinter.TclError, bdb.BdbQuit, macpath.norm_error, tabnanny.NannyNag, and xdrlib.Error. - Constants BOM_UTF8, BOM_UTF16, BOM_UTF16_LE, BOM_UTF16_BE, BOM_UTF32, BOM_UTF32_LE and BOM_UTF32_BE that represent the Byte Order Mark in UTF-8, UTF-16 and UTF-32 encodings for little and big endian systems were added to the codecs module. The old names BOM32_* and BOM64_* were off by a factor of 2. - Added conversion functions math.degrees() and math.radians(). - math.log() now takes an optional argument: math.log(x[, base]). - ftplib.retrlines() now tests for callback is None rather than testing for False. Was causing an error when given a callback object which was callable but also returned len() as zero. The change may create new breakage if the caller relied on the undocumented behavior and called with callback set to [] or some other False value not identical to None. - random.gauss() uses a piece of hidden state used by nothing else, and the .seed() and .whseed() methods failed to reset it. In other words, setting the seed didn't completely determine the sequence of results produced by random.gauss(). It does now. Programs repeatedly mixing calls to a seed method with calls to gauss() may see different results now. - The pickle.Pickler class grew a clear_memo() method to mimic that provided by cPickle.Pickler. - difflib's SequenceMatcher class now does a dynamic analysis of which elements are so frequent as to constitute noise. For comparing files as sequences of lines, this generally works better than the IS_LINE_JUNK function, and function ndiff's linejunk argument defaults to None now as a result. A happy benefit is that SequenceMatcher may run much faster now when applied to large files with many duplicate lines (for example, C program text with lots of repeated "}" and "return NULL;" lines). - New Text.dump() method in Tkinter module. - New distutils commands for building packagers were added to support pkgtool on Solaris and swinstall on HP-UX. - distutils now has a new abstract binary packager base class command/bdist_packager, which simplifies writing packagers. This will hopefully provide the missing bits to encourage people to submit more packagers, e.g. for Debian, FreeBSD and other systems. - The UTF-16, -LE and -BE stream readers now raise a NotImplementedError for all calls to .readline(). Previously, they used to just produce garbage or fail with an encoding error -- UTF-16 is a 2-byte encoding and the C lib's line reading APIs don't work well with these. - compileall now supports quiet operation. - The BaseHTTPServer now implements optional HTTP/1.1 persistent connections. - socket module: the SSL support was broken out of the main _socket module C helper and placed into a new _ssl helper which now gets imported by socket.py if available and working. - encodings package: added aliases for all supported IANA character sets - ftplib: to safeguard the user's privacy, anonymous login will use "anonymous@" as default password, rather than the real user and host name. - webbrowser: tightened up the command passed to os.system() so that arbitrary shell code can't be executed because a bogus URL was passed in. - gettext.translation has an optional fallback argument, and gettext.find an optional all argument. Translations will now fallback on a per-message basis. The module supports plural forms, by means of gettext.[d]ngettext and Translation.[u]ngettext. - distutils bdist commands now offer a --skip-build option. - warnings.warn now accepts a Warning instance as first argument. - The xml.sax.expatreader.ExpatParser class will no longer create circular references by using itself as the locator that gets passed to the content handler implementation. [SF bug #535474] - The email.Parser.Parser class now properly parses strings regardless of their line endings, which can be any of \r, \n, or \r\n (CR, LF, or CRLF). Also, the Header class's constructor default arguments has changed slightly so that an explicit maxlinelen value is always honored, and so unicode conversion error handling can be specified. - distutils' build_ext command now links C++ extensions with the C++ compiler available in the Makefile or CXX environment variable, if running under \*nix. - New module bz2: provides a comprehensive interface for the bz2 compression library. It implements a complete file interface, one-shot (de)compression functions, and types for sequential (de)compression. - New pdb command 'pp' which is like 'p' except that it pretty-prints the value of its expression argument. - Now bdist_rpm distutils command understands a verify_script option in the config file, including the contents of the referred filename in the "%verifyscript" section of the rpm spec file. - Fixed bug #495695: webbrowser module would run graphic browsers in a unix environment even if DISPLAY was not set. Also, support for skipstone browser was included. - Fixed bug #636769: rexec would run unallowed code if subclasses of strings were used as parameters for certain functions. Tools/Demos ----------- - pygettext.py now supports globbing on Windows, and accepts module names in addition to accepting file names. - The SGI demos (Demo/sgi) have been removed. Nobody thought they were interesting any more. (The SGI library modules and extensions are still there; it is believed that at least some of these are still used and useful.) - IDLE supports the new encoding declarations (PEP 263); it can also deal with legacy 8-bit files if they use the locale's encoding. It allows non-ASCII strings in the interactive shell and executes them in the locale's encoding. - freeze.py now produces binaries which can import shared modules, unlike before when this failed due to missing symbol exports in the generated binary. Build ----- - On Unix, IDLE is now installed automatically. - The fpectl module is not built by default; it's dangerous or useless except in the hands of experts. - The public Python C API will generally be declared using PyAPI_FUNC and PyAPI_DATA macros, while Python extension module init functions will be declared with PyMODINIT_FUNC. DL_EXPORT/DL_IMPORT macros are deprecated. - A bug was fixed that could cause COUNT_ALLOCS builds to segfault, or get into infinite loops, when a new-style class got garbage-collected. Unfortunately, to avoid this, the way COUNT_ALLOCS works requires that new-style classes be immortal in COUNT_ALLOCS builds. Note that COUNT_ALLOCS is not enabled by default, in either release or debug builds, and that new-style classes are immortal only in COUNT_ALLOCS builds. - Compiling out the cyclic garbage collector is no longer an option. The old symbol WITH_CYCLE_GC is now ignored, and Python.h arranges that it's always defined (for the benefit of any extension modules that may be conditionalizing on it). A bonus is that any extension type participating in cyclic gc can choose to participate in the Py_TRASHCAN mechanism now too; in the absence of cyclic gc, this used to require editing the core to teach the trashcan mechanism about the new type. - According to Annex F of the current C standard, The Standard C macro HUGE_VAL and its float and long double analogs, HUGE_VALF and HUGE_VALL, expand to expressions whose values are positive infinities. Python only uses the double HUGE_VAL, and only to #define its own symbol Py_HUGE_VAL. Some platforms have incorrect definitions for HUGE_VAL. pyport.h used to try to worm around that, but the workarounds triggered other bugs on other platforms, so we gave up. If your platform defines HUGE_VAL incorrectly, you'll need to #define Py_HUGE_VAL to something that works on your platform. The only instance of this I'm sure about is on an unknown subset of Cray systems, described here: http://www.cray.com/swpubs/manuals/SN-2194_2.0/html-SN-2194_2.0/x3138.htm Presumably 2.3a1 breaks such systems. If anyone uses such a system, help! - The configure option --without-doc-strings can be used to remove the doc strings from the builtin functions and modules; this reduces the size of the executable. - The universal newlines option (PEP 278) is on by default. On Unix it can be disabled by passing --without-universal-newlines to the configure script. On other platforms, remove WITH_UNIVERSAL_NEWLINES from pyconfig.h. - On Unix, a shared libpython2.3.so can be created with --enable-shared. - All uses of the CACHE_HASH, INTERN_STRINGS, and DONT_SHARE_SHORT_STRINGS preprocessor symbols were eliminated. The internal decisions they controlled stopped being experimental long ago. - The tools used to build the documentation now work under Cygwin as well as Unix. - The bsddb and dbm module builds have been changed to try and avoid version skew problems and disable linkage with Berkeley DB 1.85 unless the installer knows what s/he's doing. See the section on building these modules in the README file for details. C API ----- - PyNumber_Check() now returns true for string and unicode objects. This is a result of these types having a partially defined tp_as_number slot. (This is not a feature, but an indication that PyNumber_Check() is not very useful to determine numeric behavior. It may be deprecated.) - The string object's layout has changed: the pointer member ob_sinterned has been replaced by an int member ob_sstate. On some platforms (e.g. most 64-bit systems) this may change the offset of the ob_sval member, so as a precaution the API_VERSION has been incremented. The apparently unused feature of "indirect interned strings", supported by the ob_sinterned member, is gone. Interned strings are now usually mortal; there is a new API, PyString_InternImmortal() that creates immortal interned strings. (The ob_sstate member can only take three values; however, while making it a char saves a few bytes per string object on average, in it also slowed things down a bit because ob_sval was no longer aligned.) - The Py_InitModule*() functions now accept NULL for the 'methods' argument. Modules without global functions are becoming more common now that factories can be types rather than functions. - New C API PyUnicode_FromOrdinal() which exposes unichr() at C level. - New functions PyErr_SetExcFromWindowsErr() and PyErr_SetExcFromWindowsErrWithFilename(). Similar to PyErr_SetFromWindowsErrWithFilename() and PyErr_SetFromWindowsErr(), but they allow to specify the exception type to raise. Available on Windows. - Py_FatalError() is now declared as taking a const char* argument. It was previously declared without const. This should not affect working code. - Added new macro PySequence_ITEM(o, i) that directly calls sq_item without rechecking that o is a sequence and without adjusting for negative indices. - PyRange_New() now raises ValueError if the fourth argument is not 1. This is part of the removal of deprecated features of the xrange object. - PyNumber_Coerce() and PyNumber_CoerceEx() now also invoke the type's coercion if both arguments have the same type but this type has the CHECKTYPES flag set. This is to better support proxies. - The type of tp_free has been changed from "``void (*)(PyObject *)``" to "``void (*)(void *)``". - PyObject_Del, PyObject_GC_Del are now functions instead of macros. - A type can now inherit its metatype from its base type. Previously, when PyType_Ready() was called, if ob_type was found to be NULL, it was always set to &PyType_Type; now it is set to base->ob_type, where base is tp_base, defaulting to &PyObject_Type. - PyType_Ready() accidentally did not inherit tp_is_gc; now it does. - The PyCore_* family of APIs have been removed. - The "u#" parser marker will now pass through Unicode objects as-is without going through the buffer API. - The enumerators of cmp_op have been renamed to use the prefix ``PyCmp_``. - An old #define of ANY as void has been removed from pyport.h. This hasn't been used since Python's pre-ANSI days, and the #define has been marked as obsolete since then. SF bug 495548 says it created conflicts with other packages, so keeping it around wasn't harmless. - Because Python's magic number scheme broke on January 1st, we decided to stop Python development. Thanks for all the fish! - Some of us don't like fish, so we changed Python's magic number scheme to a new one. See Python/import.c for details. New platforms ------------- - OpenVMS is now supported. - AtheOS is now supported. - the EMX runtime environment on OS/2 is now supported. - GNU/Hurd is now supported. Tests ----- - The regrtest.py script's -u option now provides a way to say "allow all resources except this one." For example, to allow everything except bsddb, give the option '-uall,-bsddb'. Windows ------- - The Windows distribution now ships with version 4.0.14 of the Sleepycat Berkeley database library. This should be a huge improvement over the previous Berkeley DB 1.85, which had many bugs. XXX What are the licensing issues here? XXX If a user has a database created with a previous version of XXX Python, what must they do to convert it? XXX I'm still not sure how to link this thing (see PCbuild/readme.txt). XXX The version # is likely to change before 2.3a1. - The Windows distribution now ships with a Secure Sockets Library (SLL) module (_ssl.pyd) - The Windows distribution now ships with Tcl/Tk version 8.4.1 (it previously shipped with Tcl/Tk 8.3.2). - When Python is built under a Microsoft compiler, sys.version now includes the compiler version number (_MSC_VER). For example, under MSVC 6, sys.version contains the substring "MSC v.1200 ". 1200 is the value of _MSC_VER under MSVC 6. - Sometimes the uninstall executable (UNWISE.EXE) vanishes. One cause of that has been fixed in the installer (disabled Wise's "delete in- use files" uninstall option). - Fixed a bug in urllib's proxy handling in Windows. [SF bug #503031] - The installer now installs Start menu shortcuts under (the local equivalent of) "All Users" when doing an Admin install. - file.truncate([newsize]) now works on Windows for all newsize values. It used to fail if newsize didn't fit in 32 bits, reflecting a limitation of MS _chsize (which is no longer used). - os.waitpid() is now implemented for Windows, and can be used to block until a specified process exits. This is similar to, but not exactly the same as, os.waitpid() on POSIX systems. If you're waiting for a specific process whose pid was obtained from one of the spawn() functions, the same Python os.waitpid() code works across platforms. See the docs for details. The docs were changed to clarify that spawn functions return, and waitpid requires, a process handle on Windows (not the same thing as a Windows process id). - New tempfile.TemporaryFile implementation for Windows: this doesn't need a TemporaryFileWrapper wrapper anymore, and should be immune to a nasty problem: before 2.3, if you got a temp file on Windows, it got wrapped in an object whose close() method first closed the underlying file, then deleted the file. This usually worked fine. However, the spawn family of functions on Windows create (at a low C level) the same set of open files in the spawned process Q as were open in the spawning process P. If a temp file f was among them, then doing f.close() in P first closed P's C-level file handle on f, but Q's C-level file handle on f remained open, so the attempt in P to delete f blew up with a "Permission denied" error (Windows doesn't allow deleting open files). This was surprising, subtle, and difficult to work around. - The os module now exports all the symbolic constants usable with the low-level os.open() on Windows: the new constants in 2.3 are O_NOINHERIT, O_SHORT_LIVED, O_TEMPORARY, O_RANDOM and O_SEQUENTIAL. The others were also available in 2.2: O_APPEND, O_BINARY, O_CREAT, O_EXCL, O_RDONLY, O_RDWR, O_TEXT, O_TRUNC and O_WRONLY. Contrary to Microsoft docs, O_SHORT_LIVED does not seem to imply O_TEMPORARY (so specify both if you want both; note that neither is useful unless specified with O_CREAT too). Mac ---- - Mac/Relnotes is gone, the release notes are now here. - Python (the OSX-only, unix-based version, not the OS9-compatible CFM version) now fully supports unicode strings as arguments to various file system calls, eg. open(), file(), os.stat() and os.listdir(). - The current naming convention for Python on the Macintosh is that MacPython refers to the unix-based OSX-only version, and MacPython-OS9 refers to the CFM-based version that runs on both OS9 and OSX. - All MacPython-OS9 functionality is now available in an OSX unix build, including the Carbon modules, the IDE, OSA support, etc. A lot of this will only work correctly in a framework build, though, because you cannot talk to the window manager unless your application is run from a .app bundle. There is a command line tool "pythonw" that runs your script with an interpreter living in such a .app bundle, this interpreter should be used to run any Python script using the window manager (including Tkinter or wxPython scripts). - Most of Mac/Lib has moved to Lib/plat-mac, which is again used both in MacPython-OSX and MacPython-OS9. The only modules remaining in Mac/Lib are specifically for MacPython-OS9 (CFM support, preference resources, etc). - A new utility PythonLauncher will start a Python interpreter when a .py or .pyw script is double-clicked in the Finder. By default .py scripts are run with a normal Python interpreter in a Terminal window and .pyw files are run with a window-aware pythonw interpreter without a Terminal window, but all this can be customized. - MacPython-OS9 is now Carbon-only, so it runs on Mac OS 9 or Mac OS X and possibly on Mac OS 8.6 with the right CarbonLib installed, but not on earlier releases. - Many tools such as BuildApplet.py and gensuitemodule.py now support a command line interface too. - All the Carbon classes are now PEP253 compliant, meaning that you can subclass them from Python. Most of the attributes have gone, you should now use the accessor function call API, which is also what Apple's documentation uses. Some attributes such as grafport.visRgn are still available for convenience. - New Carbon modules File (implementing the APIs in Files.h and Aliases.h) and Folder (APIs from Folders.h). The old macfs builtin module is gone, and replaced by a Python wrapper around the new modules. - Pathname handling should now be fully consistent: MacPython-OSX always uses unix pathnames and MacPython-OS9 always uses colon-separated Mac pathnames (also when running on Mac OS X). - New Carbon modules Help and AH give access to the Carbon Help Manager. There are hooks in the IDE to allow accessing the Python documentation (and Apple's Carbon and Cocoa documentation) through the Help Viewer. See Mac/OSX/README for converting the Python documentation to a Help Viewer compatible form and installing it. - OSA support has been redesigned and the generated Python classes now mirror the inheritance defined by the underlying OSA classes. - MacPython no longer maps both \r and \n to \n on input for any text file. This feature has been replaced by universal newline support (PEP278). - The default encoding for Python sourcefiles in MacPython-OS9 is no longer mac-roman (or whatever your local Mac encoding was) but "ascii", like on other platforms. If you really need sourcefiles with Mac characters in them you can change this in site.py. What's New in Python 2.2 final? =============================== *Release date: 21-Dec-2001* Type/class unification and new-style classes -------------------------------------------- - pickle.py, cPickle: allow pickling instances of new-style classes with a custom metaclass. Core and builtins ----------------- - weakref proxy object: when comparing, unwrap both arguments if both are proxies. Extension modules ----------------- - binascii.b2a_base64(): fix a potential buffer overrun when encoding very short strings. - cPickle: the obscure "fast" mode was suspected of causing stack overflows on the Mac. Hopefully fixed this by setting the recursion limit much smaller. If the limit is too low (it only affects performance), you can change it by defining PY_CPICKLE_FAST_LIMIT when compiling cPickle.c (or in pyconfig.h). Library ------- - dumbdbm.py: fixed a dumb old bug (the file didn't get synched at close or delete time). - rfc822.py: fixed a bug where the address '<>' was converted to None instead of an empty string (also fixes the email.Utils module). - xmlrpclib.py: version 1.0.0; uses precision for doubles. - test suite: the pickle and cPickle tests were not executing any code when run from the standard regression test. Tools/Demos ----------- Build ----- C API ----- New platforms ------------- Tests ----- Windows ------- - distutils package: fixed broken Windows installers (bdist_wininst). - tempfile.py: prevent mysterious warnings when TemporaryFileWrapper instances are deleted at process exit time. - socket.py: prevent mysterious warnings when socket instances are deleted at process exit time. - posixmodule.c: fix a Windows crash with stat() of a filename ending in backslash. Mac ---- - The Carbon toolbox modules have been upgraded to Universal Headers 3.4, and experimental CoreGraphics and CarbonEvents modules have been added. All only for framework-enabled MacOSX. What's New in Python 2.2c1? =========================== *Release date: 14-Dec-2001* Type/class unification and new-style classes -------------------------------------------- - Guido's tutorial introduction to the new type/class features has been extensively updated. See http://www.python.org/2.2/descrintro.html That remains the primary documentation in this area. - Fixed a leak: instance variables declared with __slots__ were never deleted! - The "delete attribute" method of descriptor objects is called __delete__, not __del__. In previous releases, it was mistakenly called __del__, which created an unfortunate overloading condition with finalizers. (The "get attribute" and "set attribute" methods are still called __get__ and __set__, respectively.) - Some subtle issues with the super built-in were fixed: (a) When super itself is subclassed, its __get__ method would still return an instance of the base class (i.e., of super). (b) super(C, C()).__class__ would return C rather than super. This is confusing. To fix this, I decided to change the semantics of super so that it only applies to code attributes, not to data attributes. After all, overriding data attributes is not supported anyway. (c) The __get__ method didn't check whether the argument was an instance of the type used in creation of the super instance. - Previously, hash() of an instance of a subclass of a mutable type (list or dictionary) would return some value, rather than raising TypeError. This has been fixed. Also, directly calling dict.__hash__ and list.__hash__ now raises the same TypeError (previously, these were the same as object.__hash__). - New-style objects now support deleting their __dict__. This is for all intents and purposes equivalent to assigning a brand new empty dictionary, but saves space if the object is not used further. Core and builtins ----------------- - -Qnew now works as documented in PEP 238: when -Qnew is passed on the command line, all occurrences of "/" use true division instead of classic division. See the PEP for details. Note that "all" means all instances in library and 3rd-party modules, as well as in your own code. As the PEP says, -Qnew is intended for use only in educational environments with control over the libraries in use. Note that test_coercion.py in the standard Python test suite fails under -Qnew; this is expected, and won't be repaired until true division becomes the default (in the meantime, test_coercion is testing the current rules). - complex() now only allows the first argument to be a string argument, and raises TypeError if either the second arg is a string or if the second arg is specified when the first is a string. Extension modules ----------------- - gc.get_referents was renamed to gc.get_referrers. Library ------- - Functions in the os.spawn() family now release the global interpreter lock around calling the platform spawn. They should always have done this, but did not before 2.2c1. Multithreaded programs calling an os.spawn function with P_WAIT will no longer block all Python threads until the spawned program completes. It's possible that some programs relies on blocking, although more likely by accident than by design. - webbrowser defaults to netscape.exe on OS/2 now. - Tix.ResizeHandle exposes detach_widget, hide, and show. - The charset alias windows_1252 has been added. - types.StringTypes is a tuple containing the defined string types; usually this will be (str, unicode), but if Python was compiled without Unicode support it will be just (str,). - The pulldom and minidom modules were synchronized to PyXML. Tools/Demos ----------- - A new script called Tools/scripts/google.py was added, which fires off a search on Google. Build ----- - Note that release builds of Python should arrange to define the preprocessor symbol NDEBUG on the command line (or equivalent). In the 2.2 pre-release series we tried to define this by magic in Python.h instead, but it proved to cause problems for extension authors. The Unix, Windows and Mac builds now all define NDEBUG in release builds via cmdline (or equivalent) instead. Ports to other platforms should do likewise. - It is no longer necessary to use --with-suffix when building on a case-insensitive file system (such as Mac OS X HFS+). In the build directory an extension is used, but not in the installed python. C API ----- - New function PyDict_MergeFromSeq2() exposes the builtin dict constructor's logic for updating a dictionary from an iterable object producing key-value pairs. - PyArg_ParseTupleAndKeywords() requires that the number of entries in the keyword list equal the number of argument specifiers. This wasn't checked correctly, and PyArg_ParseTupleAndKeywords could even dump core in some bad cases. This has been repaired. As a result, PyArg_ParseTupleAndKeywords may raise RuntimeError in bad cases that previously went unchallenged. New platforms ------------- Tests ----- Windows ------- Mac ---- - In unix-Python on Mac OS X (and darwin) sys.platform is now "darwin", without any trailing digits. - Changed logic for finding python home in Mac OS X framework Pythons. Now sys.executable points to the executable again, in stead of to the shared library. The latter is used only for locating the python home. What's New in Python 2.2b2? =========================== *Release date: 16-Nov-2001* Type/class unification and new-style classes -------------------------------------------- - Multiple inheritance mixing new-style and classic classes in the list of base classes is now allowed, so this works now: class Classic: pass class Mixed(Classic, object): pass The MRO (method resolution order) for each base class is respected according to its kind, but the MRO for the derived class is computed using new-style MRO rules if any base class is a new-style class. This needs to be documented. - The new builtin dictionary() constructor, and dictionary type, have been renamed to dict. This reflects a decade of common usage. - dict() now accepts an iterable object producing 2-sequences. For example, dict(d.items()) == d for any dictionary d. The argument, and the elements of the argument, can be any iterable objects. - New-style classes can now have a __del__ method, which is called when the instance is deleted (just like for classic classes). - Assignment to object.__dict__ is now possible, for objects that are instances of new-style classes that have a __dict__ (unless the base class forbids it). - Methods of built-in types now properly check for keyword arguments (formerly these were silently ignored). The only built-in methods that take keyword arguments are __call__, __init__ and __new__. - The socket function has been converted to a type; see below. Core and builtins ----------------- - Assignment to __debug__ raises SyntaxError at compile-time. This was promised when 2.1c1 was released as "What's New in Python 2.1c1" (see below) says. - Clarified the error messages for unsupported operands to an operator (like 1 + ''). Extension modules ----------------- - mmap has a new keyword argument, "access", allowing a uniform way for both Windows and Unix users to create read-only, write-through and copy-on-write memory mappings. This was previously possible only on Unix. A new keyword argument was required to support this in a uniform way because the mmap() signatures had diverged across platforms. Thanks to Jay T Miller for repairing this! - By default, the gc.garbage list now contains only those instances in unreachable cycles that have __del__ methods; in 2.1 it contained all instances in unreachable cycles. "Instances" here has been generalized to include instances of both new-style and old-style classes. - The socket module defines a new method for socket objects, sendall(). This is like send() but may make multiple calls to send() until all data has been sent. Also, the socket function has been converted to a subclassable type, like list and tuple (etc.) before it; socket and SocketType are now the same thing. - Various bugfixes to the curses module. There is now a test suite for the curses module (you have to run it manually). - binascii.b2a_base64 no longer places an arbitrary restriction of 57 bytes on its input. Library ------- - tkFileDialog exposes a Directory class and askdirectory convenience function. - Symbolic group names in regular expressions must be unique. For example, the regexp r'(?P)(?P)' is not allowed, because a single name can't mean both "group 1" and "group 2" simultaneously. Python 2.2 detects this error at regexp compilation time; previously, the error went undetected, and results were unpredictable. Also in sre, the pattern.split(), pattern.sub(), and pattern.subn() methods have been rewritten in C. Also, an experimental function/method finditer() has been added, which works like findall() but returns an iterator. - Tix exposes more commands through the classes DirSelectBox, DirSelectDialog, ListNoteBook, Meter, CheckList, and the methods tix_addbitmapdir, tix_cget, tix_configure, tix_filedialog, tix_getbitmap, tix_getimage, tix_option_get, and tix_resetoptions. - Traceback objects are now scanned by cyclic garbage collection, so cycles created by casual use of sys.exc_info() no longer cause permanent memory leaks (provided garbage collection is enabled). - os.extsep -- a new variable needed by the RISCOS support. It is the separator used by extensions, and is '.' on all platforms except RISCOS, where it is '/'. There is no need to use this variable unless you have a masochistic desire to port your code to RISCOS. - mimetypes.py has optional support for non-standard, but commonly found types. guess_type() and guess_extension() now accept an optional 'strict' flag, defaulting to true, which controls whether recognize non-standard types or not. A few non-standard types we know about have been added. Also, when run as a script, there are new -l and -e options. - statcache is now deprecated. - email.Utils.formatdate() now produces the preferred RFC 2822 style dates with numeric timezones (it used to produce obsolete dates hard coded to "GMT" timezone). An optional 'localtime' flag is added to produce dates in the local timezone, with daylight savings time properly taken into account. - In pickle and cPickle, instead of masking errors in load() by transforming them into SystemError, we let the original exception propagate out. Also, implement support for __safe_for_unpickling__ in pickle, as it already was supported in cPickle. Tools/Demos ----------- Build ----- - The dbm module is built using libdb1 if available. The bsddb module is built with libdb3 if available. - Misc/Makefile.pre.in has been removed by BDFL pronouncement. C API ----- - New function PySequence_Fast_GET_SIZE() returns the size of a non- NULL result from PySequence_Fast(), more quickly than calling PySequence_Size(). - New argument unpacking function PyArg_UnpackTuple() added. - New functions PyObject_CallFunctionObjArgs() and PyObject_CallMethodObjArgs() have been added to make it more convenient and efficient to call functions and methods from C. - PyArg_ParseTupleAndKeywords() no longer masks errors, so it's possible that this will propagate errors it didn't before. - New function PyObject_CheckReadBuffer(), which returns true if its argument supports the single-segment readable buffer interface. New platforms ------------- - We've finally confirmed that this release builds on HP-UX 11.00, *with* threads, and passes the test suite. - Thanks to a series of patches from Michael Muller, Python may build again under OS/2 Visual Age C++. - Updated RISCOS port by Dietmar Schwertberger. Tests ----- - Added a test script for the curses module. It isn't run automatically; regrtest.py must be run with '-u curses' to enable it. Windows ------- Mac ---- - PythonScript has been moved to unsupported and is slated to be removed completely in the next release. - It should now be possible to build applets that work on both OS9 and OSX. - The core is now linked with CoreServices not Carbon; as a side result, default 8bit encoding on OSX is now ASCII. - Python should now build on OSX 10.1.1 What's New in Python 2.2b1? =========================== *Release date: 19-Oct-2001* Type/class unification and new-style classes -------------------------------------------- - New-style classes are now always dynamic (except for built-in and extension types). There is no longer a performance penalty, and I no longer see another reason to keep this baggage around. One relic remains: the __dict__ of a new-style class is a read-only proxy; you must set the class's attribute to modify it. As a consequence, the __defined__ attribute of new-style types no longer exists, for lack of need: there is once again only one __dict__ (although in the future a __cache__ may be resurrected with a similar function, if I can prove that it actually speeds things up). - C.__doc__ now works as expected for new-style classes (in 2.2a4 it always returned None, even when there was a class docstring). - doctest now finds and runs docstrings attached to new-style classes, class methods, static methods, and properties. Core and builtins ----------------- - A very subtle syntactical pitfall in list comprehensions was fixed. For example: [a+b for a in 'abc', for b in 'def']. The comma in this example is a mistake. Previously, this would silently let 'a' iterate over the singleton tuple ('abc',), yielding ['abcd', 'abce', 'abcf'] rather than the intended ['ad', 'ae', 'af', 'bd', 'be', 'bf', 'cd', 'ce', 'cf']. Now, this is flagged as a syntax error. Note that [a for a in ] is a convoluted way to say [] anyway, so it's not like any expressiveness is lost. - getattr(obj, name, default) now only catches AttributeError, as documented, rather than returning the default value for all exceptions (which could mask bugs in a __getattr__ hook, for example). - Weak reference objects are now part of the core and offer a C API. A bug which could allow a core dump when binary operations involved proxy reference has been fixed. weakref.ReferenceError is now a built-in exception. - unicode(obj) now behaves more like str(obj), accepting arbitrary objects, and calling a __unicode__ method if it exists. unicode(obj, encoding) and unicode(obj, encoding, errors) still require an 8-bit string or character buffer argument. - isinstance() now allows any object as the first argument and a class, a type or something with a __bases__ tuple attribute for the second argument. The second argument may also be a tuple of a class, type, or something with __bases__, in which case isinstance() will return true if the first argument is an instance of any of the things contained in the second argument tuple. E.g. isinstance(x, (A, B)) returns true if x is an instance of A or B. Extension modules ----------------- - thread.start_new_thread() now returns the thread ID (previously None). - binascii has now two quopri support functions, a2b_qp and b2a_qp. - readline now supports setting the startup_hook and the pre_event_hook, and adds the add_history() function. - os and posix supports chroot(), setgroups() and unsetenv() where available. The stat(), fstat(), statvfs() and fstatvfs() functions now return "pseudo-sequences" -- the various fields can now be accessed as attributes (e.g. os.stat("/").st_mtime) but for backwards compatibility they also behave as a fixed-length sequence. Some platform-specific fields (e.g. st_rdev) are only accessible as attributes. - time: localtime(), gmtime() and strptime() now return a pseudo-sequence similar to the os.stat() return value, with attributes like tm_year etc. - Decompression objects in the zlib module now accept an optional second parameter to decompress() that specifies the maximum amount of memory to use for the uncompressed data. - optional SSL support in the socket module now exports OpenSSL functions RAND_add(), RAND_egd(), and RAND_status(). These calls are useful on platforms like Solaris where OpenSSL does not automatically seed its PRNG. Also, the keyfile and certfile arguments to socket.ssl() are now optional. - posixmodule (and by extension, the os module on POSIX platforms) now exports O_LARGEFILE, O_DIRECT, O_DIRECTORY, and O_NOFOLLOW. Library ------- - doctest now excludes functions and classes not defined by the module being tested, thanks to Tim Hochberg. - HotShot, a new profiler implemented using a C-based callback, has been added. This substantially reduces the overhead of profiling, but it is still quite preliminary. Support modules and documentation will be added in upcoming releases (before 2.2 final). - profile now produces correct output in situations where an exception raised in Python is cleared by C code (e.g. hasattr()). This used to cause wrong output, including spurious claims of recursive functions and attribution of time spent to the wrong function. The code and documentation for the derived OldProfile and HotProfile profiling classes was removed. The code hasn't worked for years (if you tried to use them, they raised exceptions). OldProfile intended to reproduce the behavior of the profiler Python used more than 7 years ago, and isn't interesting anymore. HotProfile intended to provide a faster profiler (but producing less information), and that's a worthy goal we intend to meet via a different approach (but without losing information). - Profile.calibrate() has a new implementation that should deliver a much better system-specific calibration constant. The constant can now be specified in an instance constructor, or as a Profile class or instance variable, instead of by editing profile.py's source code. Calibration must still be done manually (see the docs for the profile module). Note that Profile.calibrate() must be overridden by subclasses. Improving the accuracy required exploiting detailed knowledge of profiler internals; the earlier method abstracted away the details and measured a simplified model instead, but consequently computed a constant too small by a factor of 2 on some modern machines. - quopri's encode and decode methods take an optional header parameter, which indicates whether output is intended for the header 'Q' encoding. - The SocketServer.ThreadingMixIn class now closes the request after finish_request() returns. (Not when it errors out though.) - The nntplib module's NNTP.body() method has grown a 'file' argument to allow saving the message body to a file. - The email package has added a class email.Parser.HeaderParser which only parses headers and does not recurse into the message's body. Also, the module/class MIMEAudio has been added for representing audio data (contributed by Anthony Baxter). - ftplib should be able to handle files > 2GB. - ConfigParser.getboolean() now also interprets TRUE, FALSE, YES, NO, ON, and OFF. - xml.dom.minidom NodeList objects now support the length attribute and item() method as required by the DOM specifications. Tools/Demos ----------- - Demo/dns was removed. It no longer serves any purpose; a package derived from it is now maintained by Anthony Baxter, see http://PyDNS.SourceForge.net. - The freeze tool has been made more robust, and two new options have been added: -X and -E. Build ----- - configure will use CXX in LINKCC if CXX is used to build main() and the system requires to link a C++ main using the C++ compiler. C API ----- - The documentation for the tp_compare slot is updated to require that the return value must be -1, 0, 1; an arbitrary number <0 or >0 is not correct. This is not yet enforced but will be enforced in Python 2.3; even later, we may use -2 to indicate errors and +2 for "NotImplemented". Right now, -1 should be used for an error return. - PyLong_AsLongLong() now accepts int (as well as long) arguments. Consequently, PyArg_ParseTuple's 'L' code also accepts int (as well as long) arguments. - PyThread_start_new_thread() now returns a long int giving the thread ID, if one can be calculated; it returns -1 for error, 0 if no thread ID is calculated (this is an incompatible change, but only the thread module used this API). This code has only really been tested on Linux and Windows; other platforms please beware (and report any bugs or strange behavior). - PyUnicode_FromEncodedObject() no longer accepts Unicode objects as input. New platforms ------------- Tests ----- Windows ------- - Installer: If you install IDLE, and don't disable file-extension registration, a new "Edit with IDLE" context (right-click) menu entry is created for .py and .pyw files. - The signal module now supports SIGBREAK on Windows, thanks to Steven Scott. Note that SIGBREAK is unique to Windows. The default SIGBREAK action remains to call Win32 ExitProcess(). This can be changed via signal.signal(). For example:: # Make Ctrl+Break raise KeyboardInterrupt, like Python's default Ctrl+C # (SIGINT) behavior. import signal signal.signal(signal.SIGBREAK, signal.default_int_handler) try: while 1: pass except KeyboardInterrupt: # We get here on Ctrl+C or Ctrl+Break now; if we had not changed # SIGBREAK, only on Ctrl+C (and Ctrl+Break would terminate the # program without the possibility for any Python-level cleanup). print "Clean exit" What's New in Python 2.2a4? =========================== *Release date: 28-Sep-2001* Type/class unification and new-style classes -------------------------------------------- - pydoc and inspect are now aware of new-style classes; e.g. help(list) at the interactive prompt now shows proper documentation for all operations on list objects. - Applications using Jim Fulton's ExtensionClass module can now safely be used with Python 2.2. In particular, Zope 2.4.1 now works with Python 2.2 (as well as with Python 2.1.1). The Demo/metaclass examples also work again. It is hoped that Gtk and Boost also work with 2.2a4 and beyond. (If you can confirm this, please write webmaster@python.org; if there are still problems, please open a bug report on SourceForge.) - property() now takes 4 keyword arguments: fget, fset, fdel and doc. These map to read-only attributes 'fget', 'fset', 'fdel', and '__doc__' in the constructed property object. fget, fset and fdel weren't discoverable from Python in 2.2a3. __doc__ is new, and allows to associate a docstring with a property. - Comparison overloading is now more completely implemented. For example, a str subclass instance can properly be compared to a str instance, and it can properly overload comparison. Ditto for most other built-in object types. - The repr() of new-style classes has changed; instead of a new-style class is now rendered as , *except* for built-in types, which are still rendered as (to avoid upsetting existing code that might parse or otherwise rely on repr() of certain type objects). - The repr() of new-style objects is now always ; previously, it was sometimes . - For new-style classes, what was previously called __getattr__ is now called __getattribute__. This method, if defined, is called for *every* attribute access. A new __getattr__ hook more similar to the one in classic classes is defined which is called only if regular attribute access raises AttributeError; to catch *all* attribute access, you can use __getattribute__ (for new-style classes). If both are defined, __getattribute__ is called first, and if it raises AttributeError, __getattr__ is called. - The __class__ attribute of new-style objects can be assigned to. The new class must have the same C-level object layout as the old class. - The builtin file type can be subclassed now. In the usual pattern, "file" is the name of the builtin type, and file() is a new builtin constructor, with the same signature as the builtin open() function. file() is now the preferred way to open a file. - Previously, __new__ would only see sequential arguments passed to the type in a constructor call; __init__ would see both sequential and keyword arguments. This made no sense whatsoever any more, so now both __new__ and __init__ see all arguments. - Previously, hash() applied to an instance of a subclass of str or unicode always returned 0. This has been repaired. - Previously, an operation on an instance of a subclass of an immutable type (int, long, float, complex, tuple, str, unicode), where the subtype didn't override the operation (and so the operation was handled by the builtin type), could return that instance instead a value of the base type. For example, if s was of a str subclass type, s[:] returned s as-is. Now it returns a str with the same value as s. - Provisional support for pickling new-style objects has been added. Core ---- - file.writelines() now accepts any iterable object producing strings. - PyUnicode_FromEncodedObject() now works very much like PyObject_Str(obj) in that it tries to use __str__/tp_str on the object if the object is not a string or buffer. This makes unicode() behave like str() when applied to non-string/buffer objects. - PyFile_WriteObject now passes Unicode objects to the file's write method. As a result, all file-like objects which may be the target of a print statement must support Unicode objects, i.e. they must at least convert them into ASCII strings. - Thread scheduling on Solaris should be improved; it is no longer necessary to insert a small sleep at the start of a thread in order to let other runnable threads be scheduled. Library ------- - StringIO.StringIO instances and cStringIO.StringIO instances support read character buffer compatible objects for their .write() methods. These objects are converted to strings and then handled as such by the instances. - The "email" package has been added. This is basically a port of the mimelib package with API changes and some implementations updated to use iterators and generators. - difflib.ndiff() and difflib.Differ.compare() are generators now. This restores the ability of Tools/scripts/ndiff.py to start producing output before the entire comparison is complete. - StringIO.StringIO instances and cStringIO.StringIO instances support iteration just like file objects (i.e. their .readline() method is called for each iteration until it returns an empty string). - The codecs module has grown four new helper APIs to access builtin codecs: getencoder(), getdecoder(), getreader(), getwriter(). - SimpleXMLRPCServer: a new module (based upon SimpleHTMLServer) simplifies writing XML RPC servers. - os.path.realpath(): a new function that returns the absolute pathname after interpretation of symbolic links. On non-Unix systems, this is an alias for os.path.abspath(). - operator.indexOf() (PySequence_Index() in the C API) now works with any iterable object. - smtplib now supports various authentication and security features of the SMTP protocol through the new login() and starttls() methods. - hmac: a new module implementing keyed hashing for message authentication. - mimetypes now recognizes more extensions and file types. At the same time, some mappings not sanctioned by IANA were removed. - The "compiler" package has been brought up to date to the state of Python 2.2 bytecode generation. It has also been promoted from a Tool to a standard library package. (Tools/compiler still exists as a sample driver.) Build ----- - Large file support (LFS) is now automatic when the platform supports it; no more manual configuration tweaks are needed. On Linux, at least, it's possible to have a system whose C library supports large files but whose kernel doesn't; in this case, large file support is still enabled but doesn't do you any good unless you upgrade your kernel or share your Python executable with another system whose kernel has large file support. - The configure script now supplies plausible defaults in a cross-compilation environment. This doesn't mean that the supplied values are always correct, or that cross-compilation now works flawlessly -- but it's a first step (and it shuts up most of autoconf's warnings about AC_TRY_RUN). - The Unix build is now a bit less chatty, courtesy of the parser generator. The build is completely silent (except for errors) when using "make -s", thanks to a -q option to setup.py. C API ----- - The "structmember" API now supports some new flag bits to deny read and/or write access to attributes in restricted execution mode. New platforms ------------- - Compaq's iPAQ handheld, running the "familiar" Linux distribution (http://familiar.handhelds.org). Tests ----- - The "classic" standard tests, which work by comparing stdout to an expected-output file under Lib/test/output/, no longer stop at the first mismatch. Instead the test is run to completion, and a variant of ndiff-style comparison is used to report all differences. This is much easier to understand than the previous style of reporting. - The unittest-based standard tests now use regrtest's test_main() convention, instead of running as a side-effect of merely being imported. This allows these tests to be run in more natural and flexible ways as unittests, outside the regrtest framework. - regrtest.py is much better integrated with unittest and doctest now, especially in regard to reporting errors. Windows ------- - Large file support now also works for files > 4GB, on filesystems that support it (NTFS under Windows 2000). See "What's New in Python 2.2a3" for more detail. What's New in Python 2.2a3? =========================== *Release Date: 07-Sep-2001* Core ---- - Conversion of long to float now raises OverflowError if the long is too big to represent as a C double. - The 3-argument builtin pow() no longer allows a third non-None argument if either of the first two arguments is a float, or if both are of integer types and the second argument is negative (in which latter case the arguments are converted to float, so this is really the same restriction). - The builtin dir() now returns more information, and sometimes much more, generally naming all attributes of an object, and all attributes reachable from the object via its class, and from its class's base classes, and so on from them too. Example: in 2.2a2, dir([]) returned an empty list. In 2.2a3, >>> dir([]) ['__add__', '__class__', '__contains__', '__delattr__', '__delitem__', '__eq__', '__ge__', '__getattr__', '__getitem__', '__getslice__', '__gt__', '__hash__', '__iadd__', '__imul__', '__init__', '__le__', '__len__', '__lt__', '__mul__', '__ne__', '__new__', '__repr__', '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__str__', 'append', 'count', 'extend', 'index', 'insert', 'pop', 'remove', 'reverse', 'sort'] dir(module) continues to return only the module's attributes, though. - Overflowing operations on plain ints now return a long int rather than raising OverflowError. This is a partial implementation of PEP 237. You can use -Wdefault::OverflowWarning to enable a warning for this situation, and -Werror::OverflowWarning to revert to the old OverflowError exception. - A new command line option, -Q, is added to control run-time warnings for the use of classic division. (See PEP 238.) Possible values are -Qold, -Qwarn, -Qwarnall, and -Qnew. The default is -Qold, meaning the / operator has its classic meaning and no warnings are issued. Using -Qwarn issues a run-time warning about all uses of classic division for int and long arguments; -Qwarnall also warns about classic division for float and complex arguments (for use with fixdiv.py). [Note: the remainder of this item (preserved below) became obsolete in 2.2c1 -- -Qnew has global effect in 2.2] :: Using -Qnew is questionable; it turns on new division by default, but only in the __main__ module. You can usefully combine -Qwarn or -Qwarnall and -Qnew: this gives the __main__ module new division, and warns about classic division everywhere else. - Many built-in types can now be subclassed. This applies to int, long, float, str, unicode, and tuple. (The types complex, list and dictionary can also be subclassed; this was introduced earlier.) Note that restrictions apply when subclassing immutable built-in types: you can only affect the value of the instance by overloading __new__. You can add mutable attributes, and the subclass instances will have a __dict__ attribute, but you cannot change the "value" (as implemented by the base class) of an immutable subclass instance once it is created. - The dictionary constructor now takes an optional argument, a mapping-like object, and initializes the dictionary from its (key, value) pairs. - A new built-in type, super, has been added. This facilitates making "cooperative super calls" in a multiple inheritance setting. For an explanation, see http://www.python.org/2.2/descrintro.html#cooperation - A new built-in type, property, has been added. This enables the creation of "properties". These are attributes implemented by getter and setter functions (or only one of these for read-only or write-only attributes), without the need to override __getattr__. See http://www.python.org/2.2/descrintro.html#property - The syntax of floating-point and imaginary literals has been liberalized, to allow leading zeroes. Examples of literals now legal that were SyntaxErrors before: 00.0 0e3 0100j 07.5 00000000000000000008. - An old tokenizer bug allowed floating point literals with an incomplete exponent, such as 1e and 3.1e-. Such literals now raise SyntaxError. Library ------- - telnetlib includes symbolic names for the options, and support for setting an option negotiation callback. It also supports processing of suboptions. - The new C standard no longer requires that math libraries set errno to ERANGE on overflow. For platform libraries that exploit this new freedom, Python's overflow-checking was wholly broken. A new overflow- checking scheme attempts to repair that, but may not be reliable on all platforms (C doesn't seem to provide anything both useful and portable in this area anymore). - Asynchronous timeout actions are available through the new class threading.Timer. - math.log and math.log10 now return sensible results for even huge long arguments. For example, math.log10(10 ** 10000) ~= 10000.0. - A new function, imp.lock_held(), returns 1 when the import lock is currently held. See the docs for the imp module. - pickle, cPickle and marshal on 32-bit platforms can now correctly read dumps containing ints written on platforms where Python ints are 8 bytes. When read on a box where Python ints are 4 bytes, such values are converted to Python longs. - In restricted execution mode (using the rexec module), unmarshalling code objects is no longer allowed. This plugs a security hole. - unittest.TestResult instances no longer store references to tracebacks generated by test failures. This prevents unexpected dangling references to objects that should be garbage collected between tests. Tools ----- - Tools/scripts/fixdiv.py has been added which can be used to fix division operators as per PEP 238. Build ----- - If you are an adventurous person using Mac OS X you may want to look at Mac/OSX. There is a Makefile there that will build Python as a real Mac application, which can be used for experimenting with Carbon or Cocoa. Discussion of this on pythonmac-sig, please. C API ----- - New function PyObject_Dir(obj), like Python __builtin__.dir(obj). - Note that PyLong_AsDouble can fail! This has always been true, but no callers checked for it. It's more likely to fail now, because overflow errors are properly detected now. The proper way to check:: double x = PyLong_AsDouble(some_long_object); if (x == -1.0 && PyErr_Occurred()) { /* The conversion failed. */ } - The GC API has been changed. Extensions that use the old API will still compile but will not participate in GC. To upgrade an extension module: - rename Py_TPFLAGS_GC to PyTPFLAGS_HAVE_GC - use PyObject_GC_New or PyObject_GC_NewVar to allocate objects and PyObject_GC_Del to deallocate them - rename PyObject_GC_Init to PyObject_GC_Track and PyObject_GC_Fini to PyObject_GC_UnTrack - remove PyGC_HEAD_SIZE from object size calculations - remove calls to PyObject_AS_GC and PyObject_FROM_GC - Two new functions: PyString_FromFormat() and PyString_FromFormatV(). These can be used safely to construct string objects from a sprintf-style format string (similar to the format string supported by PyErr_Format()). New platforms ------------- - Stephen Hansen contributed patches sufficient to get a clean compile under Borland C (Windows), but he reports problems running it and ran out of time to complete the port. Volunteers? Expect a MemoryError when importing the types module; this is probably shallow, and causing later failures too. Tests ----- Windows ------- - Large file support is now enabled on Win32 platforms as well as on Win64. This means that, for example, you can use f.tell() and f.seek() to manipulate files larger than 2 gigabytes (provided you have enough disk space, and are using a Windows filesystem that supports large partitions). Windows filesystem limits: FAT has a 2GB (gigabyte) filesize limit, and large file support makes no difference there. FAT32's limit is 4GB, and files >= 2GB are easier to use from Python now. NTFS has no practical limit on file size, and files of any size can be used from Python now. - The w9xpopen hack is now used on Windows NT and 2000 too when COMPSPEC points to command.com (patch from Brian Quinlan). What's New in Python 2.2a2? =========================== *Release Date: 22-Aug-2001* Build ----- - Tim Peters developed a brand new Windows installer using Wise 8.1, generously donated to us by Wise Solutions. - configure supports a new option --enable-unicode, with the values ucs2 and ucs4 (new in 2.2a1). With --disable-unicode, the Unicode type and supporting code is completely removed from the interpreter. - A new configure option --enable-framework builds a Mac OS X framework, which "make frameworkinstall" will install. This provides a starting point for more mac-like functionality, join pythonmac-sig@python.org if you are interested in helping. - The NeXT platform is no longer supported. - The 'new' module is now statically linked. Tools ----- - The new Tools/scripts/cleanfuture.py can be used to automatically edit out obsolete future statements from Python source code. See the module docstring for details. Tests ----- - regrtest.py now knows which tests are expected to be skipped on some platforms, allowing to give clearer test result output. regrtest also has optional --use/-u switch to run normally disabled tests which require network access or consume significant disk resources. - Several new tests in the standard test suite, with special thanks to Nick Mathewson. Core ---- - The floor division operator // has been added as outlined in PEP 238. The / operator still provides classic division (and will until Python 3.0) unless "from __future__ import division" is included, in which case the / operator will provide true division. The operator module provides truediv() and floordiv() functions. Augmented assignment variants are included, as are the equivalent overloadable methods and C API methods. See the PEP for a full discussion: - Future statements are now effective in simulated interactive shells (like IDLE). This should "just work" by magic, but read Michael Hudson's "Future statements in simulated shells" PEP 264 for full details: . - The type/class unification (PEP 252-253) was integrated into the trunk and is not so tentative any more (the exact specification of some features is still tentative). A lot of work has done on fixing bugs and adding robustness and features (performance still has to come a long way). - Warnings about a mismatch in the Python API during extension import now use the Python warning framework (which makes it possible to write filters for these warnings). - A function's __dict__ (aka func_dict) will now always be a dictionary. It used to be possible to delete it or set it to None, but now both actions raise TypeErrors. It is still legal to set it to a dictionary object. Getting func.__dict__ before any attributes have been assigned now returns an empty dictionary instead of None. - A new command line option, -E, was added which disables the use of all environment variables, or at least those that are specifically significant to Python. Usually those have a name starting with "PYTHON". This was used to fix a problem where the tests fail if the user happens to have PYTHONHOME or PYTHONPATH pointing to an older distribution. Library ------- - New class Differ and new functions ndiff() and restore() in difflib.py. These package the algorithms used by the popular Tools/scripts/ndiff.py, for programmatic reuse. - New function xml.sax.saxutils.quoteattr(): Quote an XML attribute value using the minimal quoting required for the value; more reliable than using xml.sax.saxutils.escape() for attribute values. - Readline completion support for cmd.Cmd was added. - Calling os.tempnam() or os.tmpnam() generate RuntimeWarnings. - Added function threading.BoundedSemaphore() - Added Ka-Ping Yee's cgitb.py module. - The 'new' module now exposes the CO_xxx flags. - The gc module offers the get_referents function. New platforms ------------- C API ----- - Two new APIs PyOS_snprintf() and PyOS_vsnprintf() were added which provide a cross-platform implementations for the relatively new snprintf()/vsnprintf() C lib APIs. In contrast to the standard sprintf() and vsprintf() C lib APIs, these versions apply bounds checking on the used buffer which enhances protection against buffer overruns. - Unicode APIs now use name mangling to assure that mixing interpreters and extensions using different Unicode widths is rendered next to impossible. Trying to import an incompatible Unicode-aware extension will result in an ImportError. Unicode extensions writers must make sure to check the Unicode width compatibility in their extensions by using at least one of the mangled Unicode APIs in the extension. - Two new flags METH_NOARGS and METH_O are available in method definition tables to simplify implementation of methods with no arguments and a single untyped argument. Calling such methods is more efficient than calling corresponding METH_VARARGS methods. METH_OLDARGS is now deprecated. Windows ------- - "import module" now compiles module.pyw if it exists and nothing else relevant is found. What's New in Python 2.2a1? =========================== *Release date: 18-Jul-2001* Core ---- - TENTATIVELY, a large amount of code implementing much of what's described in PEP 252 (Making Types Look More Like Classes) and PEP 253 (Subtyping Built-in Types) was added. This will be released with Python 2.2a1. Documentation will be provided separately through http://www.python.org/2.2/. The purpose of releasing this with Python 2.2a1 is to test backwards compatibility. It is possible, though not likely, that a decision is made not to release this code as part of 2.2 final, if any serious backwards incompatibilities are found during alpha testing that cannot be repaired. - Generators were added; this is a new way to create an iterator (see below) using what looks like a simple function containing one or more 'yield' statements. See PEP 255. Since this adds a new keyword to the language, this feature must be enabled by including a future statement: "from __future__ import generators" (see PEP 236). Generators will become a standard feature in a future release (probably 2.3). Without this future statement, 'yield' remains an ordinary identifier, but a warning is issued each time it is used. (These warnings currently don't conform to the warnings framework of PEP 230; we intend to fix this in 2.2a2.) - The UTF-16 codec was modified to be more RFC compliant. It will now only remove BOM characters at the start of the string and then only if running in native mode (UTF-16-LE and -BE won't remove a leading BMO character). - Strings now have a new method .decode() to complement the already existing .encode() method. These two methods provide direct access to the corresponding decoders and encoders of the registered codecs. To enhance the usability of the .encode() method, the special casing of Unicode object return values was dropped (Unicode objects were auto-magically converted to string using the default encoding). Both methods will now return whatever the codec in charge of the requested encoding returns as object, e.g. Unicode codecs will return Unicode objects when decoding is requested ("äöü".decode("latin-1") will return u"äöü"). This enables codec writer to create codecs for various simple to use conversions. New codecs were added to demonstrate these new features (the .encode() and .decode() columns indicate the type of the returned objects): +---------+-----------+-----------+-----------------------------+ |Name | .encode() | .decode() | Description | +=========+===========+===========+=============================+ |uu | string | string | UU codec (e.g. for email) | +---------+-----------+-----------+-----------------------------+ |base64 | string | string | base64 codec | +---------+-----------+-----------+-----------------------------+ |quopri | string | string | quoted-printable codec | +---------+-----------+-----------+-----------------------------+ |zlib | string | string | zlib compression | +---------+-----------+-----------+-----------------------------+ |hex | string | string | 2-byte hex codec | +---------+-----------+-----------+-----------------------------+ |rot-13 | string | Unicode | ROT-13 Unicode charmap codec| +---------+-----------+-----------+-----------------------------+ - Some operating systems now support the concept of a default Unicode encoding for file system operations. Notably, Windows supports 'mbcs' as the default. The Macintosh will also adopt this concept in the medium term, although the default encoding for that platform will be other than 'mbcs'. On operating system that support non-ASCII filenames, it is common for functions that return filenames (such as os.listdir()) to return Python string objects pre-encoded using the default file system encoding for the platform. As this encoding is likely to be different from Python's default encoding, converting this name to a Unicode object before passing it back to the Operating System would result in a Unicode error, as Python would attempt to use its default encoding (generally ASCII) rather than the default encoding for the file system. In general, this change simply removes surprises when working with Unicode and the file system, making these operations work as you expect, increasing the transparency of Unicode objects in this context. See [????] for more details, including examples. - Float (and complex) literals in source code were evaluated to full precision only when running from a .py file; the same code loaded from a .pyc (or .pyo) file could suffer numeric differences starting at about the 12th significant decimal digit. For example, on a machine with IEEE-754 floating arithmetic, x = 9007199254740992.0 print long(x) printed 9007199254740992 if run directly from .py, but 9007199254740000 if from a compiled (.pyc or .pyo) file. This was due to marshal using str(float) instead of repr(float) when building code objects. marshal now uses repr(float) instead, which should reproduce floats to full machine precision (assuming the platform C float<->string I/O conversion functions are of good quality). This may cause floating-point results to change in some cases, and usually for the better, but may also cause numerically unstable algorithms to break. - The implementation of dicts suffers fewer collisions, which has speed benefits. However, the order in which dict entries appear in dict.keys(), dict.values() and dict.items() may differ from previous releases for a given dict. Nothing is defined about this order, so no program should rely on it. Nevertheless, it's easy to write test cases that rely on the order by accident, typically because of printing the str() or repr() of a dict to an "expected results" file. See Lib/test/test_support.py's new sortdict(dict) function for a simple way to display a dict in sorted order. - Many other small changes to dicts were made, resulting in faster operation along the most common code paths. - Dictionary objects now support the "in" operator: "x in dict" means the same as dict.has_key(x). - The update() method of dictionaries now accepts generic mapping objects. Specifically the argument object must support the .keys() and __getitem__() methods. This allows you to say, for example, {}.update(UserDict()) - Iterators were added; this is a generalized way of providing values to a for loop. See PEP 234. There's a new built-in function iter() to return an iterator. There's a new protocol to get the next value from an iterator using the next() method (in Python) or the tp_iternext slot (in C). There's a new protocol to get iterators using the __iter__() method (in Python) or the tp_iter slot (in C). Iterating (i.e. a for loop) over a dictionary generates its keys. Iterating over a file generates its lines. - The following functions were generalized to work nicely with iterator arguments:: map(), filter(), reduce(), zip() list(), tuple() (PySequence_Tuple() and PySequence_Fast() in C API) max(), min() join() method of strings extend() method of lists 'x in y' and 'x not in y' (PySequence_Contains() in C API) operator.countOf() (PySequence_Count() in C API) right-hand side of assignment statements with multiple targets, such as :: x, y, z = some_iterable_object_returning_exactly_3_values - Accessing module attributes is significantly faster (for example, random.random or os.path or yourPythonModule.yourAttribute). - Comparing dictionary objects via == and != is faster, and now works even if the keys and values don't support comparisons other than ==. - Comparing dictionaries in ways other than == and != is slower: there were insecurities in the dict comparison implementation that could cause Python to crash if the element comparison routines for the dict keys and/or values mutated the dicts. Making the code bulletproof slowed it down. - Collisions in dicts are resolved via a new approach, which can help dramatically in bad cases. For example, looking up every key in a dict d with d.keys() == [i << 16 for i in range(20000)] is approximately 500x faster now. Thanks to Christian Tismer for pointing out the cause and the nature of an effective cure (last December! better late than never). - repr() is much faster for large containers (dict, list, tuple). Library ------- - The constants ascii_letters, ascii_lowercase. and ascii_uppercase were added to the string module. These a locale-independent constants, unlike letters, lowercase, and uppercase. These are now use in appropriate locations in the standard library. - The flags used in dlopen calls can now be configured using sys.setdlopenflags and queried using sys.getdlopenflags. - Fredrik Lundh's xmlrpclib is now a standard library module. This provides full client-side XML-RPC support. In addition, Demo/xmlrpc/ contains two server frameworks (one SocketServer-based, one asyncore-based). Thanks to Eric Raymond for the documentation. - The xrange() object is simplified: it no longer supports slicing, repetition, comparisons, efficient 'in' checking, the tolist() method, or the start, stop and step attributes. See PEP 260. - A new function fnmatch.filter to filter lists of file names was added. - calendar.py uses month and day names based on the current locale. - strop is now *really* obsolete (this was announced before with 1.6), and issues DeprecationWarning when used (except for the four items that are still imported into string.py). - Cookie.py now sorts key+value pairs by key in output strings. - pprint.isrecursive(object) didn't correctly identify recursive objects. Now it does. - pprint functions now much faster for large containers (tuple, list, dict). - New 'q' and 'Q' format codes in the struct module, corresponding to C types "long long" and "unsigned long long" (on Windows, __int64). In native mode, these can be used only when the platform C compiler supports these types (when HAVE_LONG_LONG is #define'd by the Python config process), and then they inherit the sizes and alignments of the C types. In standard mode, 'q' and 'Q' are supported on all platforms, and are 8-byte integral types. - The site module installs a new built-in function 'help' that invokes pydoc.help. It must be invoked as 'help()'; when invoked as 'help', it displays a message reminding the user to use 'help()' or 'help(object)'. Tests ----- - New test_mutants.py runs dict comparisons where the key and value comparison operators mutate the dicts randomly during comparison. This rapidly causes Python to crash under earlier releases (not for the faint of heart: it can also cause Win9x to freeze or reboot!). - New test_pprint.py verifies that pprint.isrecursive() and pprint.isreadable() return sensible results. Also verifies that simple cases produce correct output. C API ----- - Removed the unused last_is_sticky argument from the internal _PyTuple_Resize(). If this affects you, you were cheating. What's New in Python 2.1 (final)? ================================= We only changed a few things since the last release candidate, all in Python library code: - A bug in the locale module was fixed that affected locales which define no grouping for numeric formatting. - A few bugs in the weakref module's implementations of weak dictionaries (WeakValueDictionary and WeakKeyDictionary) were fixed, and the test suite was updated to check for these bugs. - An old bug in the os.path.walk() function (introduced in Python 2.0!) was fixed: a non-existent file would cause an exception instead of being ignored. - Fixed a few bugs in the new symtable module found by Neil Norwitz's PyChecker. What's New in Python 2.1c2? =========================== A flurry of small changes, and one showstopper fixed in the nick of time made it necessary to release another release candidate. The list here is the *complete* list of patches (except version updates): Core - Tim discovered a nasty bug in the dictionary code, caused by PyDict_Next() calling dict_resize(), and the GC code's use of PyDict_Next() violating an assumption in dict_items(). This was fixed with considerable amounts of band-aid, but the net effect is a saner and more robust implementation. - Made a bunch of symbols static that were accidentally global. Build and Ports - The setup.py script didn't check for a new enough version of zlib (1.1.3 is needed). Now it does. - Changed "make clean" target to also remove shared libraries. - Added a more general warning about the SGI Irix optimizer to README. Library - Fix a bug in urllib.basejoin("http://host", "../file.html") which omitted the slash between host and file.html. - The mailbox module's _Mailbox class contained a completely broken and undocumented seek() method. Ripped it out. - Fixed a bunch of typos in various library modules (urllib2, smtpd, sgmllib, netrc, chunk) found by Neil Norwitz's PyChecker. - Fixed a few last-minute bugs in unittest. Extensions - Reverted the patch to the OpenSSL code in socketmodule.c to support RAND_status() and the EGD, and the subsequent patch that tried to fix it for pre-0.9.5 versions; the problem with the patch is that on some systems it issues a warning whenever socket is imported, and that's unacceptable. Tests - Fixed the pickle tests to work with "import test.test_pickle". - Tweaked test_locale.py to actually run the test Windows. - In distutils/archive_util.py, call zipfile.ZipFile() with mode "w", not "wb" (which is not a valid mode at all). - Fix pstats browser crashes. Import readline if it exists to make the user interface nicer. - Add "import thread" to the top of test modules that import the threading module (test_asynchat and test_threadedtempfile). This prevents test failures caused by a broken threading module resulting from a previously caught failed import. - Changed test_asynchat.py to set the SO_REUSEADDR option; this was needed on some platforms (e.g. Solaris 8) when the tests are run twice in succession. - Skip rather than fail test_sunaudiodev if no audio device is found. What's New in Python 2.1c1? =========================== This list was significantly updated when 2.1c2 was released; the 2.1c1 release didn't mention most changes that were actually part of 2.1c1: Legal - Copyright was assigned to the Python Software Foundation (PSF) and a PSF license (very similar to the CNRI license) was added. - The CNRI copyright notice was updated to include 2001. Core - After a public outcry, assignment to __debug__ is no longer illegal; instead, a warning is issued. It will become illegal in 2.2. - Fixed a core dump with "%#x" % 0, and changed the semantics so that "%#x" now always prepends "0x", even if the value is zero. - Fixed some nits in the bytecode compiler. - Fixed core dumps when calling certain kinds of non-functions. - Fixed various core dumps caused by reference count bugs. Build and Ports - Use INSTALL_SCRIPT to install script files. - New port: SCO Unixware 7, by Billy G. Allie. - Updated RISCOS port. - Updated BeOS port and notes. - Various other porting problems resolved. Library - The TERMIOS and SOCKET modules are now truly obsolete and unnecessary. Their symbols are incorporated in the termios and socket modules. - Fixed some 64-bit bugs in pickle, cPickle, and struct, and added better tests for pickling. - threading: make Condition.wait() robust against KeyboardInterrupt. - zipfile: add support to zipfile to support opening an archive represented by an open file rather than a file name. Fix bug where the archive was not properly closed. Fixed a bug in this bugfix where flush() was called for a read-only file. - imputil: added an uninstall() method to the ImportManager. - Canvas: fixed bugs in lower() and tkraise() methods. - SocketServer: API change (added overridable close_request() method) so that the TCP server can explicitly close the request. - pstats: Eric Raymond added a simple interactive statistics browser, invoked when the module is run as a script. - locale: fixed a problem in format(). - webbrowser: made it work when the BROWSER environment variable has a value like "/usr/bin/netscape". Made it auto-detect Konqueror for KDE 2. Fixed some other nits. - unittest: changes to allow using a different exception than AssertionError, and added a few more function aliases. Some other small changes. - urllib, urllib2: fixed redirect problems and a coupleof other nits. - asynchat: fixed a critical bug in asynchat that slipped through the 2.1b2 release. Fixed another rare bug. - Fix some unqualified except: clauses (always a bad code example). XML - pyexpat: new API get_version_string(). - Fixed some minidom bugs. Extensions - Fixed a core dump in _weakref. Removed the weakref.mapping() function (it adds nothing to the API). - Rationalized the use of header files in the readline module, to make it compile (albeit with some warnings) with the very recent readline 4.2, without breaking for earlier versions. - Hopefully fixed a buffering problem in linuxaudiodev. - Attempted a fix to make the OpenSSL support in the socket module work again with pre-0.9.5 versions of OpenSSL. Tests - Added a test case for asynchat and asyncore. - Removed coupling between tests where one test failing could break another. Tools - Ping added an interactive help browser to pydoc, fixed some nits in the rest of the pydoc code, and added some features to his inspect module. - An updated python-mode.el version 4.1 which integrates Ken Manheimer's pdbtrack.el. This makes debugging Python code via pdb much nicer in XEmacs and Emacs. When stepping through your program with pdb, in either the shell window or the *Python* window, the source file and line will be tracked by an arrow. Very cool! - IDLE: syntax warnings in interactive mode are changed into errors. - Some improvements to Tools/webchecker (ignore some more URL types, follow some more links). - Brought the Tools/compiler package up to date. What's New in Python 2.1 beta 2? ================================ (Unlisted are many fixed bugs, more documentation, etc.) Core language, builtins, and interpreter - The nested scopes work (enabled by "from __future__ import nested_scopes") is completed; in particular, the future now extends into code executed through exec, eval() and execfile(), and into the interactive interpreter. - When calling a base class method (e.g. BaseClass.__init__(self)), this is now allowed even if self is not strictly spoken a class instance (e.g. when using metaclasses or the Don Beaudry hook). - Slice objects are now comparable but not hashable; this prevents dict[:] from being accepted but meaningless. - Complex division is now calculated using less braindead algorithms. This doesn't change semantics except it's more likely to give useful results in extreme cases. Complex repr() now uses full precision like float repr(). - sgmllib.py now calls handle_decl() for simple declarations. - It is illegal to assign to the name __debug__, which is set when the interpreter starts. It is effectively a compile-time constant. - A warning will be issued if a global statement for a variable follows a use or assignment of that variable. Standard library - unittest.py, a unit testing framework by Steve Purcell (PyUNIT, inspired by JUnit), is now part of the standard library. You now have a choice of two testing frameworks: unittest requires you to write testcases as separate code, doctest gathers them from docstrings. Both approaches have their advantages and disadvantages. - A new module Tix was added, which wraps the Tix extension library for Tk. With that module, it is not necessary to statically link Tix with _tkinter, since Tix will be loaded with Tcl's "package require" command. See Demo/tix/. - tzparse.py is now obsolete. - In gzip.py, the seek() and tell() methods are removed -- they were non-functional anyway, and it's better if callers can test for their existence with hasattr(). Python/C API - PyDict_Next(): it is now safe to call PyDict_SetItem() with a key that's already in the dictionary during a PyDict_Next() iteration. This used to fail occasionally when a dictionary resize operation could be triggered that would rehash all the keys. All other modifications to the dictionary are still off-limits during a PyDict_Next() iteration! - New extended APIs related to passing compiler variables around. - New abstract APIs PyObject_IsInstance(), PyObject_IsSubclass() implement isinstance() and issubclass(). - Py_BuildValue() now has a "D" conversion to create a Python complex number from a Py_complex C value. - Extensions types which support weak references must now set the field allocated for the weak reference machinery to NULL themselves; this is done to avoid the cost of checking each object for having a weakly referencable type in PyObject_INIT(), since most types are not weakly referencable. - PyFrame_FastToLocals() and PyFrame_LocalsToFast() copy bindings for free variables and cell variables to and from the frame's f_locals. - Variants of several functions defined in pythonrun.h have been added to support the nested_scopes future statement. The variants all end in Flags and take an extra argument, a PyCompilerFlags *; examples: PyRun_AnyFileExFlags(), PyRun_InteractiveLoopFlags(). These variants may be removed in Python 2.2, when nested scopes are mandatory. Distutils - the sdist command now writes a PKG-INFO file, as described in PEP 241, into the release tree. - several enhancements to the bdist_wininst command from Thomas Heller (an uninstaller, more customization of the installer's display) - from Jack Jansen: added Mac-specific code to generate a dialog for users to specify the command-line (because providing a command-line with MacPython is awkward). Jack also made various fixes for the Mac and the Metrowerks compiler. - added 'platforms' and 'keywords' to the set of metadata that can be specified for a distribution. - applied patches from Jason Tishler to make the compiler class work with Cygwin. What's New in Python 2.1 beta 1? ================================ Core language, builtins, and interpreter - Following an outcry from the community about the amount of code broken by the nested scopes feature introduced in 2.1a2, we decided to make this feature optional, and to wait until Python 2.2 (or at least 6 months) to make it standard. The option can be enabled on a per-module basis by adding "from __future__ import nested_scopes" at the beginning of a module (before any other statements, but after comments and an optional docstring). See PEP 236 (Back to the __future__) for a description of the __future__ statement. PEP 227 (Statically Nested Scopes) has been updated to reflect this change, and to clarify the semantics in a number of endcases. - The nested scopes code, when enabled, has been hardened, and most bugs and memory leaks in it have been fixed. - Compile-time warnings are now generated for a number of conditions that will break or change in meaning when nested scopes are enabled: - Using "from...import *" or "exec" without in-clause in a function scope that also defines a lambda or nested function with one or more free (non-local) variables. The presence of the import* or bare exec makes it impossible for the compiler to determine the exact set of local variables in the outer scope, which makes it impossible to determine the bindings for free variables in the inner scope. To avoid the warning about import *, change it into an import of explicitly name object, or move the import* statement to the global scope; to avoid the warning about bare exec, use exec...in... (a good idea anyway -- there's a possibility that bare exec will be deprecated in the future). - Use of a global variable in a nested scope with the same name as a local variable in a surrounding scope. This will change in meaning with nested scopes: the name in the inner scope will reference the variable in the outer scope rather than the global of the same name. To avoid the warning, either rename the outer variable, or use a global statement in the inner function. - An optional object allocator has been included. This allocator is optimized for Python objects and should be faster and use less memory than the standard system allocator. It is not enabled by default because of possible thread safety problems. The allocator is only protected by the Python interpreter lock and it is possible that some extension modules require a thread safe allocator. The object allocator can be enabled by providing the "--with-pymalloc" option to configure. Standard library - pyexpat now detects the expat version if expat.h defines it. A number of additional handlers are provided, which are only available since expat 1.95. In addition, the methods SetParamEntityParsing and GetInputContext of Parser objects are available with 1.95.x only. Parser objects now provide the ordered_attributes and specified_attributes attributes. A new module expat.model was added, which offers a number of additional constants if 1.95.x is used. - xml.dom offers the new functions registerDOMImplementation and getDOMImplementation. - xml.dom.minidom offers a toprettyxml method. A number of DOM conformance issues have been resolved. In particular, Element now has an hasAttributes method, and the handling of namespaces was improved. - Ka-Ping Yee contributed two new modules: inspect.py, a module for getting information about live Python code, and pydoc.py, a module for interactively converting docstrings to HTML or text. Tools/scripts/pydoc, which is now automatically installed into /bin, uses pydoc.py to display documentation; try running "pydoc -h" for instructions. "pydoc -g" pops up a small GUI that lets you browse the module docstrings using a web browser. - New library module difflib.py, primarily packaging the SequenceMatcher class at the heart of the popular ndiff.py file-comparison tool. - doctest.py (a framework for verifying Python code examples in docstrings) is now part of the std library. Windows changes - A new entry in the Start menu, "Module Docs", runs "pydoc -g" -- a small GUI that lets you browse the module docstrings using your default web browser. - Import is now case-sensitive. PEP 235 (Import on Case-Insensitive Platforms) is implemented. See http://python.sourceforge.net/peps/pep-0235.html for full details, especially the "Current Lower-Left Semantics" section. The new Windows import rules are simpler than before: A. If the PYTHONCASEOK environment variable exists, same as before: silently accept the first case-insensitive match of any kind; raise ImportError if none found. B. Else search sys.path for the first case-sensitive match; raise ImportError if none found. The same rules have been implemented on other platforms with case- insensitive but case-preserving filesystems too (including Cygwin, and several flavors of Macintosh operating systems). - winsound module: Under Win9x, winsound.Beep() now attempts to simulate what it's supposed to do (and does do under NT and 2000) via direct port manipulation. It's unknown whether this will work on all systems, but it does work on my Win98SE systems now and was known to be useless on all Win9x systems before. - Build: Subproject _test (effectively) renamed to _testcapi. New platforms - 2.1 should compile and run out of the box under MacOS X, even using HFS+. Thanks to Steven Majewski! - 2.1 should compile and run out of the box on Cygwin. Thanks to Jason Tishler! - 2.1 contains new files and patches for RISCOS, thanks to Dietmar Schwertberger! See RISCOS/README for more information -- it seems that because of the bizarre filename conventions on RISCOS, no port to that platform is easy. What's New in Python 2.1 alpha 2? ================================= Core language, builtins, and interpreter - Scopes nest. If a name is used in a function or class, but is not local, the definition in the nearest enclosing function scope will be used. One consequence of this change is that lambda statements could reference variables in the namespaces where the lambda is defined. In some unusual cases, this change will break code. In all previous version of Python, names were resolved in exactly three namespaces -- the local namespace, the global namespace, and the builtin namespace. According to this old definition, if a function A is defined within a function B, the names bound in B are not visible in A. The new rules make names bound in B visible in A, unless A contains a name binding that hides the binding in B. Section 4.1 of the reference manual describes the new scoping rules in detail. The test script in Lib/test/test_scope.py demonstrates some of the effects of the change. The new rules will cause existing code to break if it defines nested functions where an outer function has local variables with the same name as globals or builtins used by the inner function. Example: def munge(str): def helper(x): return str(x) if type(str) != type(''): str = helper(str) return str.strip() Under the old rules, the name str in helper() is bound to the builtin function str(). Under the new rules, it will be bound to the argument named str and an error will occur when helper() is called. - The compiler will report a SyntaxError if "from ... import *" occurs in a function or class scope. The language reference has documented that this case is illegal, but the compiler never checked for it. The recent introduction of nested scope makes the meaning of this form of name binding ambiguous. In a future release, the compiler may allow this form when there is no possibility of ambiguity. - repr(string) is easier to read, now using hex escapes instead of octal, and using \t, \n and \r instead of \011, \012 and \015 (respectively): >>> "\texample \r\n" + chr(0) + chr(255) '\texample \r\n\x00\xff' # in 2.1 '\011example \015\012\000\377' # in 2.0 - Functions are now compared and hashed by identity, not by value, since the func_code attribute is writable. - Weak references (PEP 205) have been added. This involves a few changes in the core, an extension module (_weakref), and a Python module (weakref). The weakref module is the public interface. It includes support for "explicit" weak references, proxy objects, and mappings with weakly held values. - A 'continue' statement can now appear in a try block within the body of a loop. It is still not possible to use continue in a finally clause. Standard library - mailbox.py now has a new class, PortableUnixMailbox which is identical to UnixMailbox but uses a more portable scheme for determining From_ separators. Also, the constructors for all the classes in this module have a new optional `factory' argument, which is a callable used when new message classes must be instantiated by the next() method. - random.py is now self-contained, and offers all the functionality of the now-deprecated whrandom.py. See the docs for details. random.py also supports new functions getstate() and setstate(), for saving and restoring the internal state of the generator; and jumpahead(n), for quickly forcing the internal state to be the same as if n calls to random() had been made. The latter is particularly useful for multi- threaded programs, creating one instance of the random.Random() class for each thread, then using .jumpahead() to force each instance to use a non-overlapping segment of the full period. - random.py's seed() function is new. For bit-for-bit compatibility with prior releases, use the whseed function instead. The new seed function addresses two problems: (1) The old function couldn't produce more than about 2**24 distinct internal states; the new one about 2**45 (the best that can be done in the Wichmann-Hill generator). (2) The old function sometimes produced identical internal states when passed distinct integers, and there was no simple way to predict when that would happen; the new one guarantees to produce distinct internal states for all arguments in [0, 27814431486576L). - The socket module now supports raw packets on Linux. The socket family is AF_PACKET. - test_capi.py is a start at running tests of the Python C API. The tests are implemented by the new Modules/_testmodule.c. - A new extension module, _symtable, provides provisional access to the internal symbol table used by the Python compiler. A higher-level interface will be added on top of _symtable in a future release. - Removed the obsolete soundex module. - xml.dom.minidom now uses the standard DOM exceptions. Node supports the isSameNode method; NamedNodeMap the get method. - xml.sax.expatreader supports the lexical handler property; it generates comment, startCDATA, and endCDATA events. Windows changes - Build procedure: the zlib project is built in a different way that ensures the zlib header files used can no longer get out of synch with the zlib binary used. See PCbuild\readme.txt for details. Your old zlib-related directories can be deleted; you'll need to download fresh source for zlib and unpack it into a new directory. - Build: New subproject _test for the benefit of test_capi.py (see above). - Build: New subproject _symtable, for new DLL _symtable.pyd (a nascent interface to some Python compiler internals). - Build: Subproject ucnhash is gone, since the code was folded into the unicodedata subproject. What's New in Python 2.1 alpha 1? ================================= Core language, builtins, and interpreter - There is a new Unicode companion to the PyObject_Str() API called PyObject_Unicode(). It behaves in the same way as the former, but assures that the returned value is an Unicode object (applying the usual coercion if necessary). - The comparison operators support "rich comparison overloading" (PEP 207). C extension types can provide a rich comparison function in the new tp_richcompare slot in the type object. The cmp() function and the C function PyObject_Compare() first try the new rich comparison operators before trying the old 3-way comparison. There is also a new C API PyObject_RichCompare() (which also falls back on the old 3-way comparison, but does not constrain the outcome of the rich comparison to a Boolean result). The rich comparison function takes two objects (at least one of which is guaranteed to have the type that provided the function) and an integer indicating the opcode, which can be Py_LT, Py_LE, Py_EQ, Py_NE, Py_GT, Py_GE (for <, <=, ==, !=, >, >=), and returns a Python object, which may be NotImplemented (in which case the tp_compare slot function is used as a fallback, if defined). Classes can overload individual comparison operators by defining one or more of the methods__lt__, __le__, __eq__, __ne__, __gt__, __ge__. There are no explicit "reflected argument" versions of these; instead, __lt__ and __gt__ are each other's reflection, likewise for__le__ and __ge__; __eq__ and __ne__ are their own reflection (similar at the C level). No other implications are made; in particular, Python does not assume that == is the Boolean inverse of !=, or that < is the Boolean inverse of >=. This makes it possible to define types with partial orderings. Classes or types that want to implement (in)equality tests but not the ordering operators (i.e. unordered types) should implement == and !=, and raise an error for the ordering operators. It is possible to define types whose rich comparison results are not Boolean; e.g. a matrix type might want to return a matrix of bits for A < B, giving elementwise comparisons. Such types should ensure that any interpretation of their value in a Boolean context raises an exception, e.g. by defining __nonzero__ (or the tp_nonzero slot at the C level) to always raise an exception. - Complex numbers use rich comparisons to define == and != but raise an exception for <, <=, > and >=. Unfortunately, this also means that cmp() of two complex numbers raises an exception when the two numbers differ. Since it is not mathematically meaningful to compare complex numbers except for equality, I hope that this doesn't break too much code. - The outcome of comparing non-numeric objects of different types is not defined by the language, other than that it's arbitrary but consistent (see the Reference Manual). An implementation detail changed in 2.1a1 such that None now compares less than any other object. Code relying on this new behavior (like code that relied on the previous behavior) does so at its own risk. - Functions and methods now support getting and setting arbitrarily named attributes (PEP 232). Functions have a new __dict__ (a.k.a. func_dict) which hold the function attributes. Methods get and set attributes on their underlying im_func. It is a TypeError to set an attribute on a bound method. - The xrange() object implementation has been improved so that xrange(sys.maxint) can be used on 64-bit platforms. There's still a limitation that in this case len(xrange(sys.maxint)) can't be calculated, but the common idiom "for i in xrange(sys.maxint)" will work fine as long as the index i doesn't actually reach 2**31. (Python uses regular ints for sequence and string indices; fixing that is much more work.) - Two changes to from...import: 1) "from M import X" now works even if (after loading module M) sys.modules['M'] is not a real module; it's basically a getattr() operation with AttributeError exceptions changed into ImportError. 2) "from M import *" now looks for M.__all__ to decide which names to import; if M.__all__ doesn't exist, it uses M.__dict__.keys() but filters out names starting with '_' as before. Whether or not __all__ exists, there's no restriction on the type of M. - File objects have a new method, xreadlines(). This is the fastest way to iterate over all lines in a file: for line in file.xreadlines(): ...do something to line... See the xreadlines module (mentioned below) for how to do this for other file-like objects. - Even if you don't use file.xreadlines(), you may expect a speedup on line-by-line input. The file.readline() method has been optimized quite a bit in platform-specific ways: on systems (like Linux) that support flockfile(), getc_unlocked(), and funlockfile(), those are used by default. On systems (like Windows) without getc_unlocked(), a complicated (but still thread-safe) method using fgets() is used by default. You can force use of the fgets() method by #define'ing USE_FGETS_IN_GETLINE at build time (it may be faster than getc_unlocked()). You can force fgets() not to be used by #define'ing DONT_USE_FGETS_IN_GETLINE (this is the first thing to try if std test test_bufio.py fails -- and let us know if it does!). - In addition, the fileinput module, while still slower than the other methods on most platforms, has been sped up too, by using file.readlines(sizehint). - Support for run-time warnings has been added, including a new command line option (-W) to specify the disposition of warnings. See the description of the warnings module below. - Extensive changes have been made to the coercion code. This mostly affects extension modules (which can now implement mixed-type numerical operators without having to use coercion), but occasionally, in boundary cases the coercion semantics have changed subtly. Since this was a terrible gray area of the language, this is considered an improvement. Also note that __rcmp__ is no longer supported -- instead of calling __rcmp__, __cmp__ is called with reflected arguments. - In connection with the coercion changes, a new built-in singleton object, NotImplemented is defined. This can be returned for operations that wish to indicate they are not implemented for a particular combination of arguments. From C, this is Py_NotImplemented. - The interpreter accepts now bytecode files on the command line even if they do not have a .pyc or .pyo extension. On Linux, after executing import imp,sys,string magic = string.join(["\\x%.2x" % ord(c) for c in imp.get_magic()],"") reg = ':pyc:M::%s::%s:' % (magic, sys.executable) open("/proc/sys/fs/binfmt_misc/register","wb").write(reg) any byte code file can be used as an executable (i.e. as an argument to execve(2)). - %[xXo] formats of negative Python longs now produce a sign character. In 1.6 and earlier, they never produced a sign, and raised an error if the value of the long was too large to fit in a Python int. In 2.0, they produced a sign if and only if too large to fit in an int. This was inconsistent across platforms (because the size of an int varies across platforms), and inconsistent with hex() and oct(). Example: >>> "%x" % -0x42L '-42' # in 2.1 'ffffffbe' # in 2.0 and before, on 32-bit machines >>> hex(-0x42L) '-0x42L' # in all versions of Python The behavior of %d formats for negative Python longs remains the same as in 2.0 (although in 1.6 and before, they raised an error if the long didn't fit in a Python int). %u formats don't make sense for Python longs, but are allowed and treated the same as %d in 2.1. In 2.0, a negative long formatted via %u produced a sign if and only if too large to fit in an int. In 1.6 and earlier, a negative long formatted via %u raised an error if it was too big to fit in an int. - Dictionary objects have an odd new method, popitem(). This removes an arbitrary item from the dictionary and returns it (in the form of a (key, value) pair). This can be useful for algorithms that use a dictionary as a bag of "to do" items and repeatedly need to pick one item. Such algorithms normally end up running in quadratic time; using popitem() they can usually be made to run in linear time. Standard library - In the time module, the time argument to the functions strftime, localtime, gmtime, asctime and ctime is now optional, defaulting to the current time (in the local timezone). - The ftplib module now defaults to passive mode, which is deemed a more useful default given that clients are often inside firewalls these days. Note that this could break if ftplib is used to connect to a *server* that is inside a firewall, from outside; this is expected to be a very rare situation. To fix that, you can call ftp.set_pasv(0). - The module site now treats .pth files not only for path configuration, but also supports extensions to the initialization code: Lines starting with import are executed. - There's a new module, warnings, which implements a mechanism for issuing and filtering warnings. There are some new built-in exceptions that serve as warning categories, and a new command line option, -W, to control warnings (e.g. -Wi ignores all warnings, -We turns warnings into errors). warnings.warn(message[, category]) issues a warning message; this can also be called from C as PyErr_Warn(category, message). - A new module xreadlines was added. This exports a single factory function, xreadlines(). The intention is that this code is the absolutely fastest way to iterate over all lines in an open file(-like) object: import xreadlines for line in xreadlines.xreadlines(file): ...do something to line... This is equivalent to the previous the speed record holder using file.readlines(sizehint). Note that if file is a real file object (as opposed to a file-like object), this is equivalent: for line in file.xreadlines(): ...do something to line... - The bisect module has new functions bisect_left, insort_left, bisect_right and insort_right. The old names bisect and insort are now aliases for bisect_right and insort_right. XXX_right and XXX_left methods differ in what happens when the new element compares equal to one or more elements already in the list: the XXX_left methods insert to the left, the XXX_right methods to the right. Code that doesn't care where equal elements end up should continue to use the old, short names ("bisect" and "insort"). - The new curses.panel module wraps the panel library that forms part of SYSV curses and ncurses. Contributed by Thomas Gellekum. - The SocketServer module now sets the allow_reuse_address flag by default in the TCPServer class. - A new function, sys._getframe(), returns the stack frame pointer of the caller. This is intended only as a building block for higher-level mechanisms such as string interpolation. - The pyexpat module supports a number of new handlers, which are available only in expat 1.2. If invocation of a callback fails, it will report an additional frame in the traceback. Parser objects participate now in garbage collection. If expat reports an unknown encoding, pyexpat will try to use a Python codec; that works only for single-byte charsets. The parser type objects is exposed as XMLParserObject. - xml.dom now offers standard definitions for symbolic node type and exception code constants, and a hierarchy of DOM exceptions. minidom was adjusted to use them. - The conformance of xml.dom.minidom to the DOM specification was improved. It detects a number of additional error cases; the previous/next relationship works even when the tree is modified; Node supports the normalize() method; NamedNodeMap, DocumentType and DOMImplementation classes were added; Element supports the hasAttribute and hasAttributeNS methods; and Text supports the splitText method. Build issues - For Unix (and Unix-compatible) builds, configuration and building of extension modules is now greatly automated. Rather than having to edit the Modules/Setup file to indicate which modules should be built and where their include files and libraries are, a distutils-based setup.py script now takes care of building most extension modules. All extension modules built this way are built as shared libraries. Only a few modules that must be linked statically are still listed in the Setup file; you won't need to edit their configuration. - Python should now build out of the box on Cygwin. If it doesn't, mail to Jason Tishler (jlt63 at users.sourceforge.net). - Python now always uses its own (renamed) implementation of getopt() -- there's too much variation among C library getopt() implementations. - C++ compilers are better supported; the CXX macro is always set to a C++ compiler if one is found. Windows changes - select module: By default under Windows, a select() call can specify no more than 64 sockets. Python now boosts this Microsoft default to 512. If you need even more than that, see the MS docs (you'll need to #define FD_SETSIZE and recompile Python from source). - Support for Windows 3.1, DOS and OS/2 is gone. The Lib/dos-8x3 subdirectory is no more! What's New in Python 2.0? ========================= Below is a list of all relevant changes since release 1.6. Older changes are in the file HISTORY. If you are making the jump directly from Python 1.5.2 to 2.0, make sure to read the section for 1.6 in the HISTORY file! Many important changes listed there. Alternatively, a good overview of the changes between 1.5.2 and 2.0 is the document "What's New in Python 2.0" by Kuchling and Moshe Zadka: http://www.amk.ca/python/2.0/. --Guido van Rossum (home page: http://www.pythonlabs.com/~guido/) ====================================================================== What's new in 2.0 (since release candidate 1)? ============================================== Standard library - The copy_reg module was modified to clarify its intended use: to register pickle support for extension types, not for classes. pickle() will raise a TypeError if it is passed a class. - Fixed a bug in gettext's "normalize and expand" code that prevented it from finding an existing .mo file. - Restored support for HTTP/0.9 servers in httplib. - The math module was changed to stop raising OverflowError in case of underflow, and return 0 instead in underflow cases. Whether Python used to raise OverflowError in case of underflow was platform- dependent (it did when the platform math library set errno to ERANGE on underflow). - Fixed a bug in StringIO that occurred when the file position was not at the end of the file and write() was called with enough data to extend past the end of the file. - Fixed a bug that caused Tkinter error messages to get lost on Windows. The bug was fixed by replacing direct use of interp->result with Tcl_GetStringResult(interp). - Fixed bug in urllib2 that caused it to fail when it received an HTTP redirect response. - Several changes were made to distutils: Some debugging code was removed from util. Fixed the installer used when an external zip program (like WinZip) is not found; the source code for this installer is in Misc/distutils. check_lib() was modified to behave more like AC_CHECK_LIB by add other_libraries() as a parameter. The test for whether installed modules are on sys.path was changed to use both normcase() and normpath(). - Several minor bugs were fixed in the xml package (the minidom, pulldom, expatreader, and saxutils modules). - The regression test driver (regrtest.py) behavior when invoked with -l changed: It now reports a count of objects that are recognized as garbage but not freed by the garbage collector. - The regression test for the math module was changed to test exceptional behavior when the test is run in verbose mode. Python cannot yet guarantee consistent exception behavior across platforms, so the exception part of test_math is run only in verbose mode, and may fail on your platform. Internals - PyOS_CheckStack() has been disabled on Win64, where it caused test_sre to fail. Build issues - Changed compiler flags, so that gcc is always invoked with -Wall and -Wstrict-prototypes. Users compiling Python with GCC should see exactly one warning, except if they have passed configure the --with-pydebug flag. The expected warning is for getopt() in Modules/main.c. This warning will be fixed for Python 2.1. - Fixed configure to add -threads argument during linking on OSF1. Tools and other miscellany - The compiler in Tools/compiler was updated to support the new language features introduced in 2.0: extended print statement, list comprehensions, and augmented assignments. The new compiler should also be backwards compatible with Python 1.5.2; the compiler will always generate code for the version of the interpreter it runs under. What's new in 2.0 release candidate 1 (since beta 2)? ===================================================== What is release candidate 1? We believe that release candidate 1 will fix all known bugs that we intend to fix for the 2.0 final release. This release should be a bit more stable than the previous betas. We would like to see even more widespread testing before the final release, so we are producing this release candidate. The final release will be exactly the same unless any show-stopping (or brown bag) bugs are found by testers of the release candidate. All the changes since the last beta release are bug fixes or changes to support building Python for specific platforms. Core language, builtins, and interpreter - A bug that caused crashes when __coerce__ was used with augmented assignment, e.g. +=, was fixed. - Raise ZeroDivisionError when raising zero to a negative number, e.g. 0.0 ** -2.0. Note that math.pow is unrelated to the builtin power operator and the result of math.pow(0.0, -2.0) will vary by platform. On Linux, it raises a ValueError. - A bug in Unicode string interpolation was fixed that occasionally caused errors with formats including "%%". For example, the following expression "%% %s" % u"abc" no longer raises a TypeError. - Compilation of deeply nested expressions raises MemoryError instead of SyntaxError, e.g. eval("[" * 50 + "]" * 50). - In 2.0b2 on Windows, the interpreter wrote .pyc files in text mode, rendering them useless. They are now written in binary mode again. Standard library - Keyword arguments are now accepted for most pattern and match object methods in SRE, the standard regular expression engine. - In SRE, fixed error with negative lookahead and lookbehind that manifested itself as a runtime error in patterns like "(? is now included by Python.h (if it exists). INT_MAX and LONG_MAX will always be defined, even if is not available. - PyFloat_FromString takes a second argument, pend, that was effectively useless. It is now officially useless but preserved for backwards compatibility. If the pend argument is not NULL, *pend is set to NULL. - PyObject_GetAttr() and PyObject_SetAttr() now accept Unicode objects for the attribute name. See note on getattr() above. - A few bug fixes to argument processing for Unicode. PyArg_ParseTupleAndKeywords() now accepts "es#" and "es". PyArg_Parse() special cases "s#" for Unicode objects; it returns a pointer to the default encoded string data instead of to the raw UTF-16. - Py_BuildValue accepts B format (for bgen-generated code). Internals - On Unix, fix code for finding Python installation directory so that it works when argv[0] is a relative path. - Added a true unicode_internal_encode() function and fixed the unicode_internal_decode function() to support Unicode objects directly rather than by generating a copy of the object. - Several of the internal Unicode tables are much smaller now, and the source code should be much friendlier to weaker compilers. - In the garbage collector: Fixed bug in collection of tuples. Fixed bug that caused some instances to be removed from the container set while they were still live. Fixed parsing in gc.set_debug() for platforms where sizeof(long) > sizeof(int). - Fixed refcount problem in instance deallocation that only occurred when Py_REF_DEBUG was defined and Py_TRACE_REFS was not. - On Windows, getpythonregpath is now protected against null data in registry key. - On Unix, create .pyc/.pyo files with O_EXCL flag to avoid a race condition. Build and platform-specific issues - Better support of GNU Pth via --with-pth configure option. - Python/C API now properly exposed to dynamically-loaded extension modules on Reliant UNIX. - Changes for the benefit of SunOS 4.1.4 (really!). mmapmodule.c: Don't define MS_SYNC to be zero when it is undefined. Added missing prototypes in posixmodule.c. - Improved support for HP-UX build. Threads should now be correctly configured (on HP-UX 10.20 and 11.00). - Fix largefile support on older NetBSD systems and OpenBSD by adding define for TELL64. Tools and other miscellany - ftpmirror: Call to main() is wrapped in if __name__ == "__main__". - freeze: The modulefinder now works with 2.0 opcodes. - IDLE: Move hackery of sys.argv until after the Tk instance has been created, which allows the application-specific Tkinter initialization to be executed if present; also pass an explicit className parameter to the Tk() constructor. What's new in 2.0 beta 1? ========================= Source Incompatibilities ------------------------ None. Note that 1.6 introduced several incompatibilities with 1.5.2, such as single-argument append(), connect() and bind(), and changes to str(long) and repr(float). Binary Incompatibilities ------------------------ - Third party extensions built for Python 1.5.x or 1.6 cannot be used with Python 2.0; these extensions will have to be rebuilt for Python 2.0. - On Windows, attempting to import a third party extension built for Python 1.5.x or 1.6 results in an immediate crash; there's not much we can do about this. Check your PYTHONPATH environment variable! - Python bytecode files (*.pyc and *.pyo) are not compatible between releases. Overview of Changes Since 1.6 ----------------------------- There are many new modules (including brand new XML support through the xml package, and i18n support through the gettext module); a list of all new modules is included below. Lots of bugs have been fixed. The process for making major new changes to the language has changed since Python 1.6. Enhancements must now be documented by a Python Enhancement Proposal (PEP) before they can be accepted. There are several important syntax enhancements, described in more detail below: - Augmented assignment, e.g. x += 1 - List comprehensions, e.g. [x**2 for x in range(10)] - Extended import statement, e.g. import Module as Name - Extended print statement, e.g. print >> file, "Hello" Other important changes: - Optional collection of cyclical garbage Python Enhancement Proposal (PEP) --------------------------------- PEP stands for Python Enhancement Proposal. A PEP is a design document providing information to the Python community, or describing a new feature for Python. The PEP should provide a concise technical specification of the feature and a rationale for the feature. We intend PEPs to be the primary mechanisms for proposing new features, for collecting community input on an issue, and for documenting the design decisions that have gone into Python. The PEP author is responsible for building consensus within the community and documenting dissenting opinions. The PEPs are available at http://python.sourceforge.net/peps/. Augmented Assignment -------------------- This must have been the most-requested feature of the past years! Eleven new assignment operators were added: += -= *= /= %= **= <<= >>= &= ^= |= For example, A += B is similar to A = A + B except that A is evaluated only once (relevant when A is something like dict[index].attr). However, if A is a mutable object, A may be modified in place. Thus, if A is a number or a string, A += B has the same effect as A = A+B (except A is only evaluated once); but if a is a list, A += B has the same effect as A.extend(B)! Classes and built-in object types can override the new operators in order to implement the in-place behavior; the not-in-place behavior is used automatically as a fallback when an object doesn't implement the in-place behavior. For classes, the method name is derived from the method name for the corresponding not-in-place operator by inserting an 'i' in front of the name, e.g. __iadd__ implements in-place __add__. Augmented assignment was implemented by Thomas Wouters. List Comprehensions ------------------- This is a flexible new notation for lists whose elements are computed from another list (or lists). The simplest form is: [ for in ] For example, [i**2 for i in range(4)] yields the list [0, 1, 4, 9]. This is more efficient than a for loop with a list.append() call. You can also add a condition: [ for in if ] For example, [w for w in words if w == w.lower()] would yield the list of words that contain no uppercase characters. This is more efficient than a for loop with an if statement and a list.append() call. You can also have nested for loops and more than one 'if' clause. For example, here's a function that flattens a sequence of sequences:: def flatten(seq): return [x for subseq in seq for x in subseq] flatten([[0], [1,2,3], [4,5], [6,7,8,9], []]) This prints [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] List comprehensions originated as a patch set from Greg Ewing; Skip Montanaro and Thomas Wouters also contributed. Described by PEP 202. Extended Import Statement ------------------------- Many people have asked for a way to import a module under a different name. This can be accomplished like this: import foo bar = foo del foo but this common idiom gets old quickly. A simple extension of the import statement now allows this to be written as follows: import foo as bar There's also a variant for 'from ... import': from foo import bar as spam This also works with packages; e.g. you can write this: import test.regrtest as regrtest Note that 'as' is not a new keyword -- it is recognized only in this context (this is only possible because the syntax for the import statement doesn't involve expressions). Implemented by Thomas Wouters. Described by PEP 221. Extended Print Statement ------------------------ Easily the most controversial new feature, this extension to the print statement adds an option to make the output go to a different file than the default sys.stdout. For example, to write an error message to sys.stderr, you can now write: print >> sys.stderr, "Error: bad dog!" As a special feature, if the expression used to indicate the file evaluates to None, the current value of sys.stdout is used. Thus: print >> None, "Hello world" is equivalent to print "Hello world" Design and implementation by Barry Warsaw. Described by PEP 214. Optional Collection of Cyclical Garbage --------------------------------------- Python is now equipped with a garbage collector that can hunt down cyclical references between Python objects. It's no replacement for reference counting; in fact, it depends on the reference counts being correct, and decides that a set of objects belong to a cycle if all their reference counts can be accounted for from their references to each other. This devious scheme was first proposed by Eric Tiedemann, and brought to implementation by Neil Schemenauer. There's a module "gc" that lets you control some parameters of the garbage collection. There's also an option to the configure script that lets you enable or disable the garbage collection. In 2.0b1, it's on by default, so that we (hopefully) can collect decent user experience with this new feature. There are some questions about its performance. If it proves to be too much of a problem, we'll turn it off by default in the final 2.0 release. Smaller Changes --------------- A new function zip() was added. zip(seq1, seq2, ...) is equivalent to map(None, seq1, seq2, ...) when the sequences have the same length; i.e. zip([1,2,3], [10,20,30]) returns [(1,10), (2,20), (3,30)]. When the lists are not all the same length, the shortest list wins: zip([1,2,3], [10,20]) returns [(1,10), (2,20)]. See PEP 201. sys.version_info is a tuple (major, minor, micro, level, serial). Dictionaries have an odd new method, setdefault(key, default). dict.setdefault(key, default) returns dict[key] if it exists; if not, it sets dict[key] to default and returns that value. Thus: dict.setdefault(key, []).append(item) does the same work as this common idiom: if not dict.has_key(key): dict[key] = [] dict[key].append(item) There are two new variants of SyntaxError that are raised for indentation-related errors: IndentationError and TabError. Changed \x to consume exactly two hex digits; see PEP 223. Added \U escape that consumes exactly eight hex digits. The limits on the size of expressions and file in Python source code have been raised from 2**16 to 2**32. Previous versions of Python were limited because the maximum argument size the Python VM accepted was 2**16. This limited the size of object constructor expressions, e.g. [1,2,3] or {'a':1, 'b':2}, and the size of source files. This limit was raised thanks to a patch by Charles Waldman that effectively fixes the problem. It is now much more likely that you will be limited by available memory than by an arbitrary limit in Python. The interpreter's maximum recursion depth can be modified by Python programs using sys.getrecursionlimit and sys.setrecursionlimit. This limit is the maximum number of recursive calls that can be made by Python code. The limit exists to prevent infinite recursion from overflowing the C stack and causing a core dump. The default value is 1000. The maximum safe value for a particular platform can be found by running Misc/find_recursionlimit.py. New Modules and Packages ------------------------ atexit - for registering functions to be called when Python exits. imputil - Greg Stein's alternative API for writing custom import hooks. pyexpat - an interface to the Expat XML parser, contributed by Paul Prescod. xml - a new package with XML support code organized (so far) in three subpackages: xml.dom, xml.sax, and xml.parsers. Describing these would fill a volume. There's a special feature whereby a user-installed package named _xmlplus overrides the standard xmlpackage; this is intended to give the XML SIG a hook to distribute backwards-compatible updates to the standard xml package. webbrowser - a platform-independent API to launch a web browser. Changed Modules --------------- array -- new methods for array objects: count, extend, index, pop, and remove binascii -- new functions b2a_hex and a2b_hex that convert between binary data and its hex representation calendar -- Many new functions that support features including control over which day of the week is the first day, returning strings instead of printing them. Also new symbolic constants for days of week, e.g. MONDAY, ..., SUNDAY. cgi -- FieldStorage objects have a getvalue method that works like a dictionary's get method and returns the value attribute of the object. ConfigParser -- The parser object has new methods has_option, remove_section, remove_option, set, and write. They allow the module to be used for writing config files as well as reading them. ftplib -- ntransfercmd(), transfercmd(), and retrbinary() all now optionally support the RFC 959 REST command. gzip -- readline and readlines now accept optional size arguments httplib -- New interfaces and support for HTTP/1.1 by Greg Stein. See the module doc strings for details. locale -- implement getdefaultlocale for Win32 and Macintosh marshal -- no longer dumps core when marshaling deeply nested or recursive data structures os -- new functions isatty, seteuid, setegid, setreuid, setregid os/popen2 -- popen2/popen3/popen4 support under Windows. popen2/popen3 support under Unix. os/pty -- support for openpty and forkpty os.path -- fix semantics of os.path.commonprefix smtplib -- support for sending very long messages socket -- new function getfqdn() readline -- new functions to read, write and truncate history files. The readline section of the library reference manual contains an example. select -- add interface to poll system call shutil -- new copyfileobj function SimpleHTTPServer, CGIHTTPServer -- Fix problems with buffering in the HTTP server. Tkinter -- optimization of function flatten urllib -- scans environment variables for proxy configuration, e.g. http_proxy. whichdb -- recognizes dumbdbm format Obsolete Modules ---------------- None. However note that 1.6 made a whole slew of modules obsolete: stdwin, soundex, cml, cmpcache, dircache, dump, find, grep, packmail, poly, zmod, strop, util, whatsound. Changed, New, Obsolete Tools ---------------------------- None. C-level Changes --------------- Several cleanup jobs were carried out throughout the source code. All C code was converted to ANSI C; we got rid of all uses of the Py_PROTO() macro, which makes the header files a lot more readable. Most of the portability hacks were moved to a new header file, pyport.h; several other new header files were added and some old header files were removed, in an attempt to create a more rational set of header files. (Few of these ever need to be included explicitly; they are all included by Python.h.) Trent Mick ensured portability to 64-bit platforms, under both Linux and Win64, especially for the new Intel Itanium processor. Mick also added large file support for Linux64 and Win64. The C APIs to return an object's size have been update to consistently use the form PyXXX_Size, e.g. PySequence_Size and PyDict_Size. In previous versions, the abstract interfaces used PyXXX_Length and the concrete interfaces used PyXXX_Size. The old names, e.g. PyObject_Length, are still available for backwards compatibility at the API level, but are deprecated. The PyOS_CheckStack function has been implemented on Windows by Fredrik Lundh. It prevents Python from failing with a stack overflow on Windows. The GC changes resulted in creation of two new slots on object, tp_traverse and tp_clear. The augmented assignment changes result in the creation of a new slot for each in-place operator. The GC API creates new requirements for container types implemented in C extension modules. See Include/objimpl.h for details. PyErr_Format has been updated to automatically calculate the size of the buffer needed to hold the formatted result string. This change prevents crashes caused by programmer error. New C API calls: PyObject_AsFileDescriptor, PyErr_WriteUnraisable. PyRun_AnyFileEx, PyRun_SimpleFileEx, PyRun_FileEx -- New functions that are the same as their non-Ex counterparts except they take an extra flag argument that tells them to close the file when done. XXX There were other API changes that should be fleshed out here. Windows Changes --------------- New popen2/popen3/peopen4 in os module (see Changed Modules above). os.popen is much more usable on Windows 95 and 98. See Microsoft Knowledge Base article Q150956. The Win9x workaround described there is implemented by the new w9xpopen.exe helper in the root of your Python installation. Note that Python uses this internally; it is not a standalone program. Administrator privileges are no longer required to install Python on Windows NT or Windows 2000. If you have administrator privileges, Python's registry info will be written under HKEY_LOCAL_MACHINE. Otherwise the installer backs off to writing Python's registry info under HKEY_CURRENT_USER. The latter is sufficient for all "normal" uses of Python, but will prevent some advanced uses from working (for example, running a Python script as an NT service, or possibly from CGI). [This was new in 1.6] The installer no longer runs a separate Tcl/Tk installer; instead, it installs the needed Tcl/Tk files directly in the Python directory. If you already have a Tcl/Tk installation, this wastes some disk space (about 4 Megs) but avoids problems with conflicting Tcl/Tk installations, and makes it much easier for Python to ensure that Tcl/Tk can find all its files. [This was new in 1.6] The Windows installer now installs by default in \Python20\ on the default volume, instead of \Program Files\Python-2.0\. Updates to the changes between 1.5.2 and 1.6 -------------------------------------------- The 1.6 NEWS file can't be changed after the release is done, so here is some late-breaking news: New APIs in locale.py: normalize(), getdefaultlocale(), resetlocale(), and changes to getlocale() and setlocale(). The new module is now enabled per default. It is not true that the encodings codecs cannot be used for normal strings: the string.encode() (which is also present on 8-bit strings !) allows using them for 8-bit strings too, e.g. to convert files from cp1252 (Windows) to latin-1 or vice-versa. Japanese codecs are available from Tamito KAJIYAMA: http://pseudo.grad.sccs.chukyo-u.ac.jp/~kajiyama/python/ ====================================================================== ======================================= ==> Release 1.6 (September 5, 2000) <== ======================================= What's new in release 1.6? ========================== Below is a list of all relevant changes since release 1.5.2. Source Incompatibilities ------------------------ Several small incompatible library changes may trip you up: - The append() method for lists can no longer be invoked with more than one argument. This used to append a single tuple made out of all arguments, but was undocumented. To append a tuple, use e.g. l.append((a, b, c)). - The connect(), connect_ex() and bind() methods for sockets require exactly one argument. Previously, you could call s.connect(host, port), but this was undocumented. You must now write s.connect((host, port)). - The str() and repr() functions are now different more often. For long integers, str() no longer appends a 'L'. Thus, str(1L) == '1', which used to be '1L'; repr(1L) is unchanged and still returns '1L'. For floats, repr() now gives 17 digits of precision, to ensure no precision is lost (on all current hardware). - The -X option is gone. Built-in exceptions are now always classes. Many more library modules also have been converted to class-based exceptions. Binary Incompatibilities ------------------------ - Third party extensions built for Python 1.5.x cannot be used with Python 1.6; these extensions will have to be rebuilt for Python 1.6. - On Windows, attempting to import a third party extension built for Python 1.5.x results in an immediate crash; there's not much we can do about this. Check your PYTHONPATH environment variable! Overview of Changes since 1.5.2 ------------------------------- For this overview, I have borrowed from the document "What's New in Python 2.0" by Andrew Kuchling and Moshe Zadka: http://www.amk.ca/python/2.0/ . There are lots of new modules and lots of bugs have been fixed. A list of all new modules is included below. Probably the most pervasive change is the addition of Unicode support. We've added a new fundamental datatype, the Unicode string, a new build-in function unicode(), an numerous C APIs to deal with Unicode and encodings. See the file Misc/unicode.txt for details, or http://starship.python.net/crew/lemburg/unicode-proposal.txt. Two other big changes, related to the Unicode support, are the addition of string methods and (yet another) new regular expression engine. - String methods mean that you can now say s.lower() etc. instead of importing the string module and saying string.lower(s) etc. One peculiarity is that the equivalent of string.join(sequence, delimiter) is delimiter.join(sequence). Use " ".join(sequence) for the effect of string.join(sequence); to make this more readable, try space=" " first. Note that the maxsplit argument defaults in split() and replace() have changed from 0 to -1. - The new regular expression engine, SRE by Fredrik Lundh, is fully backwards compatible with the old engine, and is in fact invoked using the same interface (the "re" module). You can explicitly invoke the old engine by import pre, or the SRE engine by importing sre. SRE is faster than pre, and supports Unicode (which was the main reason to put effort in yet another new regular expression engine -- this is at least the fourth!). Other Changes ------------- Other changes that won't break code but are nice to know about: Deleting objects is now safe even for deeply nested data structures. Long/int unifications: long integers can be used in seek() calls, as slice indexes. String formatting (s % args) has a new formatting option, '%r', which acts like '%s' but inserts repr(arg) instead of str(arg). (Not yet in alpha 1.) Greg Ward's "distutils" package is included: this will make installing, building and distributing third party packages much simpler. There's now special syntax that you can use instead of the apply() function. f(*args, **kwds) is equivalent to apply(f, args, kwds). You can also use variations f(a1, a2, *args, **kwds) and you can leave one or the other out: f(*args), f(**kwds). The built-ins int() and long() take an optional second argument to indicate the conversion base -- of course only if the first argument is a string. This makes string.atoi() and string.atol() obsolete. (string.atof() was already obsolete). When a local variable is known to the compiler but undefined when used, a new exception UnboundLocalError is raised. This is a class derived from NameError so code catching NameError should still work. The purpose is to provide better diagnostics in the following example: x = 1 def f(): print x x = x+1 This used to raise a NameError on the print statement, which confused even experienced Python programmers (especially if there are several hundreds of lines of code between the reference and the assignment to x :-). You can now override the 'in' operator by defining a __contains__ method. Note that it has its arguments backwards: x in a causes a.__contains__(x) to be called. That's why the name isn't __in__. The exception AttributeError will have a more friendly error message, e.g.: 'Spam' instance has no attribute 'eggs'. This may break code that expects the message to be exactly the attribute name. New Modules in 1.6 ------------------ UserString - base class for deriving from the string type. distutils - tools for distributing Python modules. robotparser - parse a robots.txt file, for writing web spiders. (Moved from Tools/webchecker/.) linuxaudiodev - audio for Linux. mmap - treat a file as a memory buffer. (Windows and Unix.) sre - regular expressions (fast, supports unicode). Currently, this code is very rough. Eventually, the re module will be reimplemented using sre (without changes to the re API). filecmp - supersedes the old cmp.py and dircmp.py modules. tabnanny - check Python sources for tab-width dependance. (Moved from Tools/scripts/.) urllib2 - new and improved but incompatible version of urllib (still experimental). zipfile - read and write zip archives. codecs - support for Unicode encoders/decoders. unicodedata - provides access to the Unicode 3.0 database. _winreg - Windows registry access. encodings - package which provides a large set of standard codecs -- currently only for the new Unicode support. It has a drop-in extension mechanism which allows you to add new codecs by simply copying them into the encodings package directory. Asian codec support will probably be made available as separate distribution package built upon this technique and the new distutils package. Changed Modules --------------- readline, ConfigParser, cgi, calendar, posix, readline, xmllib, aifc, chunk, wave, random, shelve, nntplib - minor enhancements. socket, httplib, urllib - optional OpenSSL support (Unix only). _tkinter - support for 8.0 up to 8.3. Support for versions older than 8.0 has been dropped. string - most of this module is deprecated now that strings have methods. This no longer uses the built-in strop module, but takes advantage of the new string methods to provide transparent support for both Unicode and ordinary strings. Changes on Windows ------------------ The installer no longer runs a separate Tcl/Tk installer; instead, it installs the needed Tcl/Tk files directly in the Python directory. If you already have a Tcl/Tk installation, this wastes some disk space (about 4 Megs) but avoids problems with conflincting Tcl/Tk installations, and makes it much easier for Python to ensure that Tcl/Tk can find all its files. Note: the alpha installers don't include the documentation. The Windows installer now installs by default in \Python16\ on the default volume, instead of \Program Files\Python-1.6\. Changed Tools ------------- IDLE - complete overhaul. See the IDLE home page for more information. (Python 1.6 alpha 1 will come with IDLE 0.6.) Tools/i18n/pygettext.py - Python equivalent of xgettext(1). A message text extraction tool used for internationalizing applications written in Python. Obsolete Modules ---------------- stdwin and everything that uses it. (Get Python 1.5.2 if you need it. :-) soundex. (Skip Montanaro has a version in Python but it won't be included in the Python release.) cmp, cmpcache, dircmp. (Replaced by filecmp.) dump. (Use pickle.) find. (Easily coded using os.walk().) grep. (Not very useful as a library module.) packmail. (No longer has any use.) poly, zmod. (These were poor examples at best.) strop. (No longer needed by the string module.) util. (This functionality was long ago built in elsewhere). whatsound. (Use sndhdr.) Detailed Changes from 1.6b1 to 1.6 ---------------------------------- - Slight changes to the CNRI license. A copyright notice has been added; the requirement to indicate the nature of modifications now applies when making a derivative work available "to others" instead of just "to the public"; the version and date are updated. The new license has a new handle. - Added the Tools/compiler package. This is a project led by Jeremy Hylton to write the Python bytecode generator in Python. - The function math.rint() is removed. - In Python.h, "#define _GNU_SOURCE 1" was added. - Version 0.9.1 of Greg Ward's distutils is included (instead of version 0.9). - A new version of SRE is included. It is more stable, and more compatible with the old RE module. Non-matching ranges are indicated by -1, not None. (The documentation said None, but the PRE implementation used -1; changing to None would break existing code.) - The winreg module has been renamed to _winreg. (There are plans for a higher-level API called winreg, but this has not yet materialized in a form that is acceptable to the experts.) - The _locale module is enabled by default. - Fixed the configuration line for the _curses module. - A few crashes have been fixed, notably .writelines() with a list containing non-string objects would crash, and there were situations where a lost SyntaxError could dump core. - The .extend() method now accepts an arbitrary sequence argument. - If __str__() or __repr__() returns a Unicode object, this is converted to an 8-bit string. - Unicode string comparisons is no longer aware of UTF-16 encoding peculiarities; it's a straight 16-bit compare. - The Windows installer now installs the LICENSE file and no longer registers the Python DLL version in the registry (this is no longer needed). It now uses Tcl/Tk 8.3.2. - A few portability problems have been fixed, in particular a compilation error involving socklen_t. - The PC configuration is slightly friendlier to non-Microsoft compilers. ====================================================================== ====================================== ==> Release 1.5.2 (April 13, 1999) <== ====================================== From 1.5.2c1 to 1.5.2 (final) ============================= Tue Apr 13 15:44:49 1999 Guido van Rossum * PCbuild/python15.wse: Bump version to 1.5.2 (final) * PCbuild/python15.dsp: Added shamodule.c * PC/config.c: Added sha module! * README, Include/patchlevel.h: Prepare for final release. * Misc/ACKS: More (Cameron Laird is honorary; the others are 1.5.2c1 testers). * Python/thread_solaris.h: While I can't really test this thoroughly, Pat Knight and the Solaris man pages suggest that the proper thing to do is to add THR_NEW_LWP to the flags on thr_create(), and that there really isn't a downside, so I'll do that. * Misc/ACKS: Bunch of new names who helped iron out the last wrinkles of 1.5.2. * PC/python_nt.rc: Bump the myusterious M$ version number from 1,5,2,1 to 1,5,2,3. (I can't even display this on NT, maybe Win/98 can?) * Lib/pstats.py: Fix mysterious references to jprofile that were in the source since its creation. I'm assuming these were once valid references to "Jim Roskind's profile"... * Lib/Attic/threading_api.py: Removed; since long subsumed in Doc/lib/libthreading.tex * Modules/socketmodule.c: Put back __osf__ support for gethostbyname_r(); the real bug was that it was being used even without threads. This of course might be an all-platform problem so now we only use the _r variant when we are using threads. Mon Apr 12 22:51:20 1999 Guido van Rossum * Modules/cPickle.c: Fix accidentally reversed NULL test in load_mark(). Suggested by Tamito Kajiyama. (This caused a bug only on platforms where malloc(0) returns NULL.) * README: Add note about popen2 problem on Linux noticed by Pablo Bleyer. * README: Add note about -D_REENTRANT for HP-UX 10.20. * Modules/Makefile.pre.in: 'clean' target should remove hassignal. * PC/Attic/vc40.mak, PC/readme.txt: Remove all VC++ info (except VC 1.5) from readme.txt; remove the VC++ 4.0 project file; remove the unused _tkinter extern defs. * README: Clarify PC build instructions (point to PCbuild). * Modules/zlibmodule.c: Cast added by Jack Jansen (for Mac port). * Lib/plat-sunos5/CDIO.py, Lib/plat-linux2/CDROM.py: Forgot to add this file. CDROM device parameters. * Lib/gzip.py: Two different changes. 1. Jack Jansen reports that on the Mac, the time may be negative, and solves this by adding a write32u() function that writes an unsigned long. 2. On 64-bit platforms the CRC comparison fails; I've fixed this by casting both values to be compared to "unsigned long" i.e. modulo 0x100000000L. Sat Apr 10 18:42:02 1999 Guido van Rossum * PC/Attic/_tkinter.def: No longer needed. * Misc/ACKS: Correct missed character in Andrew Dalke's name. * README: Add DEC Ultrix notes (from Donn Cave's email). * configure: The usual * configure.in: Quote a bunch of shell variables used in test, related to long-long. * Objects/fileobject.c, Modules/shamodule.c, Modules/regexpr.c: casts for picky compilers. * Modules/socketmodule.c: 3-arg gethostbyname_r doesn't really work on OSF/1. * PC/vc15_w31/_.c, PC/vc15_lib/_.c, Tools/pynche/__init__.py: Avoid totally empty files. Fri Apr 9 14:56:35 1999 Guido van Rossum * Tools/scripts/fixps.py: Use re instead of regex. Don't rewrite the file in place. (Reported by Andy Dustman.) * Lib/netrc.py, Lib/shlex.py: Get rid of #! line Thu Apr 8 23:13:37 1999 Guido van Rossum * PCbuild/python15.wse: Use the Tcl 8.0.5 installer. Add a variable %_TCL_% that makes it easier to switch to a different version. ====================================================================== From 1.5.2b2 to 1.5.2c1 ======================= Thu Apr 8 23:13:37 1999 Guido van Rossum * PCbuild/python15.wse: Release 1.5.2c1. Add IDLE and Uninstall to program group. Don't distribute zlib.dll. Tweak some comments. * PCbuild/zlib.dsp: Now using static zlib 1.1.3 * Lib/dos-8x3/userdict.py, Lib/dos-8x3/userlist.py, Lib/dos-8x3/test_zli.py, Lib/dos-8x3/test_use.py, Lib/dos-8x3/test_pop.py, Lib/dos-8x3/test_pic.py, Lib/dos-8x3/test_ntp.py, Lib/dos-8x3/test_gzi.py, Lib/dos-8x3/test_fcn.py, Lib/dos-8x3/test_cpi.py, Lib/dos-8x3/test_bsd.py, Lib/dos-8x3/posixfil.py, Lib/dos-8x3/mimetype.py, Lib/dos-8x3/nturl2pa.py, Lib/dos-8x3/compilea.py, Lib/dos-8x3/exceptio.py, Lib/dos-8x3/basehttp.py: The usual * Include/patchlevel.h: Release 1.5.2c1 * README: Release 1.5.2c1. * Misc/NEWS: News for the 1.5.2c1 release. * Lib/test/test_strftime.py: On Windows, we suddenly find, strftime() may return "" for an unsupported format string. (I guess this is because the logic for deciding whether to reallocate the buffer or not has been improved.) This caused the test code to crash on result[0]. Fix this by assuming an empty result also means the format is not supported. * Demo/tkinter/matt/window-creation-w-location.py: This demo imported some private code from Matt. Make it cripple along. * Lib/lib-tk/Tkinter.py: Delete an accidentally checked-in feature that actually broke more than was worth it: when deleting a canvas item, it would try to automatically delete the bindings for that item. Since there's nothing that says you can't reuse the tag and still have the bindings, this is not correct. Also, it broke at least one demo (Demo/tkinter/matt/rubber-band-box-demo-1.py). * Python/thread_wince.h: Win/CE thread support by Mark Hammond. Wed Apr 7 20:23:17 1999 Guido van Rossum * Modules/zlibmodule.c: Patch by Andrew Kuchling to unflush() (flush() for deflating). Without this, if inflate() returned Z_BUF_ERROR asking for more output space, we would report the error; now, we increase the buffer size and try again, just as for Z_OK. * Lib/test/test_gzip.py: Use binary mode for all gzip files we open. * Tools/idle/ChangeLog: New change log. * Tools/idle/README.txt, Tools/idle/NEWS.txt: New version. * Python/pythonrun.c: Alas, get rid of the Win specific hack to ask the user to press Return before exiting when an error happened. This didn't work right when Python is invoked from a daemon. * Tools/idle/idlever.py: Version bump awaiting impending new release. (Not much has changed :-( ) * Lib/lib-tk/Tkinter.py: lower, tkraise/lift hide Misc.lower, Misc.tkraise/lift, so the preferred name for them is tag_lower, tag_raise (similar to tag_bind, and similar to the Text widget); unfortunately can't delete the old ones yet (maybe in 1.6) * Python/thread.c, Python/strtod.c, Python/mystrtoul.c, Python/import.c, Python/ceval.c: Changes by Mark Hammond for Windows CE. Mostly of the form #ifdef DONT_HAVE_header_H ... #endif around #include . * Python/bltinmodule.c: Remove unused variable from complex_from_string() code. * Include/patchlevel.h: Add the possibility of a gamma release (release candidate). Add '+' to string version number to indicate we're beyond b2 now. * Modules/posixmodule.c: Add extern decl for fsync() for SunOS 4.x. * Lib/smtplib.py: Changes by Per Cederquist and The Dragon. Per writes: """ The application where Signum Support uses smtplib needs to be able to report good error messages to the user when sending email fails. To help in diagnosing problems it is useful to be able to report the entire message sent by the server, not only the SMTP error code of the offending command. A lot of the functions in sendmail.py unfortunately discards the message, leaving only the code. The enclosed patch fixes that problem. The enclosed patch also introduces a base class for exceptions that include an SMTP error code and error message, and make the code and message available on separate attributes, so that surrounding code can deal with them in whatever way it sees fit. I've also added some documentation to the exception classes. The constructor will now raise an exception if it cannot connect to the SMTP server. The data() method will raise an SMTPDataError if it doesn't receive the expected 354 code in the middle of the exchange. According to section 5.2.10 of RFC 1123 a smtp client must accept "any text, including no text at all" after the error code. If the response of a HELO command contains no text self.helo_resp will be set to the empty string (""). The patch fixes the test in the sendmail() method so that helo_resp is tested against None; if it has the empty string as value the sendmail() method would invoke the helo() method again. The code no longer accepts a -1 reply from the ehlo() method in sendmail(). [Text about removing SMTPRecipientsRefused deleted --GvR] """ and also: """ smtplib.py appends an extra blank line to the outgoing mail if the `msg' argument to the sendmail method already contains a trailing newline. This patch should fix the problem. """ The Dragon writes: """ Mostly I just re-added the SMTPRecipientsRefused exception (the exeption object now has the appropriate info in it ) [Per had removed this in his patch --GvR] and tweaked the behavior of the sendmail method whence it throws the newly added SMTPHeloException (it was closing the connection, which it shouldn't. whatever catches the exception should do that. ) I pondered the change of the return values to tuples all around, and after some thinking I decided that regularizing the return values was too much of the Right Thing (tm) to not do. My one concern is that code expecting an integer & getting a tuple may fail silently. (i.e. if it's doing : x.somemethod() >= 400: expecting an integer, the expression will always be true if it gets a tuple instead. ) However, most smtplib code I've seen only really uses the sendmail() method, so this wouldn't bother it. Usually code I've seen that calls the other methods usually only calls helo() and ehlo() for doing ESMTP, a feature which was not in the smtplib included with 1.5.1, and thus I would think not much code uses it yet. """ Tue Apr 6 19:38:18 1999 Guido van Rossum * Lib/test/test_ntpath.py: Fix the tests now that splitdrive() no longer treats UNC paths special. (Some tests converted to splitunc() tests.) * Lib/ntpath.py: Withdraw the UNC support from splitdrive(). Instead, a new function splitunc() parses UNC paths. The contributor of the UNC parsing in splitdrive() doesn't like it, but I haven't heard a good reason to keep it, and it causes some problems. (I think there's a philosophical problem -- to me, the split*() functions are purely syntactical, and the fact that \\foo is not a valid path doesn't mean that it shouldn't be considered an absolute path.) Also (quite separately, but strangely related to the philosophical issue above) fix abspath() so that if win32api exists, it doesn't fail when the path doesn't actually exist -- if GetFullPathName() fails, fall back on the old strategy (join with getcwd() if neccessary, and then use normpath()). * configure.in, configure, config.h.in, acconfig.h: For BeOS PowerPC. Chris Herborth. Mon Apr 5 21:54:14 1999 Guido van Rossum * Modules/timemodule.c: Jonathan Giddy notes, and Chris Lawrence agrees, that some comments on #else/#endif are wrong, and that #if HAVE_TM_ZONE should be #ifdef. * Misc/ACKS: Bunch of new contributors, including 9 who contributed to the Docs, reported by Fred. Mon Apr 5 18:37:59 1999 Fred Drake * Lib/gzip.py: Oops, missed mode parameter to open(). * Lib/gzip.py: Made the default mode 'rb' instead of 'r', for better cross-platform support. (Based on comment on the documentation by Bernhard Reiter ). Fri Apr 2 22:18:25 1999 Guido van Rossum * Tools/scripts/dutree.py: For reasons I dare not explain, this script should always execute main() when imported (in other words, it is not usable as a module). Thu Apr 1 15:32:30 1999 Guido van Rossum * Lib/test/test_cpickle.py: Jonathan Giddy write: In test_cpickle.py, the module os got imported, but the line to remove the temp file has gone missing. Tue Mar 30 20:17:31 1999 Guido van Rossum * Lib/BaseHTTPServer.py: Per Cederqvist writes: If you send something like "PUT / HTTP/1.0" to something derived from BaseHTTPServer that doesn't define do_PUT, you will get a response that begins like this: HTTP/1.0 501 Unsupported method ('do_PUT') Server: SimpleHTTP/0.3 Python/1.5 Date: Tue, 30 Mar 1999 18:53:53 GMT The server should complain about 'PUT' instead of 'do_PUT'. This patch should fix the problem. Mon Mar 29 20:33:21 1999 Guido van Rossum * Lib/smtplib.py: Patch by Per Cederqvist, who writes: """ - It needlessly used the makefile() method for each response that is read from the SMTP server. - If the remote SMTP server closes the connection unexpectedly the code raised an IndexError. It now raises an SMTPServerDisconnected exception instead. - The code now checks that all lines in a multiline response actually contains an error code. """ The Dragon approves. Mon Mar 29 20:25:40 1999 Fred Drake * Lib/compileall.py: When run as a script, report failures in the exit code as well. Patch largely based on changes by Andrew Dalke, as discussed in the distutils-sig. Mon Mar 29 20:23:41 1999 Guido van Rossum * Lib/urllib.py: Hack so that if a 302 or 301 redirect contains a relative URL, the right thing "just happens" (basejoin() with old URL). * Modules/cPickle.c: Protection against picling to/from closed (real) file. The problem was reported by Moshe Zadka. * Lib/test/test_cpickle.py: Test protection against picling to/from closed (real) file. * Modules/timemodule.c: Chris Lawrence writes: """ The GNU folks, in their infinite wisdom, have decided not to implement altzone in libc6; this would not be horrible, except that timezone (which is implemented) includes the current DST setting (i.e. timezone for Central is 18000 in summer and 21600 in winter). So Python's timezone and altzone variables aren't set correctly during DST. Here's a patch relative to 1.5.2b2 that (a) makes timezone and altzone show the "right" thing on Linux (by using the tm_gmtoff stuff available in BSD, which is how the GLIBC manual claims things should be done) and (b) should cope with the southern hemisphere. In pursuit of (b), I also took the liberty of renaming the "summer" and "winter" variables to "july" and "jan". This patch should also make certain time calculations on Linux actually work right (like the tz-aware functions in the rfc822 module). (It's hard to find DST that's currently being used in the southern hemisphere; I tested using Africa/Windhoek.) """ * Lib/test/output/test_gzip: Jonathan Giddy discovered this file was missing. * Modules/shamodule.c: Avoid warnings from AIX compiler. Reported by Vladimir (AIX is my middlename) Marangozov, patch coded by Greg Stein. * Tools/idle/ScriptBinding.py, Tools/idle/PyShell.py: At Tim Peters' recommendation, add a dummy flush() method to PseudoFile. Sun Mar 28 17:55:32 1999 Guido van Rossum * Tools/scripts/ndiff.py: Tim Peters writes: I should have waited overnight . Nothing wrong with the one I sent, but I couldn't resist going on to add new -r1 / -r2 cmdline options for recreating the original files from ndiff's output. That's attached, if you're game! Us Windows guys don't usually have a sed sitting around . Sat Mar 27 13:34:01 1999 Guido van Rossum * Tools/scripts/ndiff.py: Tim Peters writes: Attached is a cleaned-up version of ndiff (added useful module docstring, now echo'ed in case of cmd line mistake); added -q option to suppress initial file identification lines; + other minor cleanups, & a slightly faster match engine. Fri Mar 26 22:36:00 1999 Fred Drake * Tools/scripts/dutree.py: During display, if EPIPE is raised, it's probably because a pager was killed. Discard the error in that case, but propogate it otherwise. Fri Mar 26 16:20:45 1999 Guido van Rossum * Lib/test/output/test_userlist, Lib/test/test_userlist.py: Test suite for UserList. * Lib/UserList.py: Use isinstance() where appropriate. Reformatted with 4-space indent. Fri Mar 26 16:11:40 1999 Barry Warsaw * Tools/pynche/PyncheWidget.py: Helpwin.__init__(): The text widget should get focus. * Tools/pynche/pyColorChooser.py: Removed unnecessary import `from PyncheWidget import PyncheWidget' Fri Mar 26 15:32:05 1999 Guido van Rossum * Lib/test/output/test_userdict, Lib/test/test_userdict.py: Test suite for UserDict * Lib/UserDict.py: Improved a bunch of things. The constructor now takes an optional dictionary. Use isinstance() where appropriate. Thu Mar 25 22:38:49 1999 Guido van Rossum * Lib/test/output/test_pickle, Lib/test/output/test_cpickle, Lib/test/test_pickle.py, Lib/test/test_cpickle.py: Basic regr tests for pickle/cPickle * Lib/pickle.py: Don't use "exec" in find_class(). It's slow, unnecessary, and (as AMK points out) it doesn't work in JPython Applets. Thu Mar 25 21:50:27 1999 Andrew Kuchling * Lib/test/test_gzip.py: Added a simple test suite for gzip. It simply opens a temp file, writes a chunk of compressed data, closes it, writes another chunk, and reads the contents back to verify that they are the same. * Lib/gzip.py: Based on a suggestion from bruce@hams.com, make a trivial change to allow using the 'a' flag as a mode for opening a GzipFile. gzip files, surprisingly enough, can be concatenated and then decompressed; the effect is to concatenate the two chunks of data. If we support it on writing, it should also be supported on reading. This *wasn't* trivial, and required rearranging the code in the reading path, particularly the _read() method. Raise IOError instead of RuntimeError in two cases, 'Not a gzipped file' and 'Unknown compression method' Thu Mar 25 21:25:01 1999 Guido van Rossum * Lib/test/test_b1.py: Add tests for float() and complex() with string args (Nick/Stephanie Lockwood). Thu Mar 25 21:21:08 1999 Andrew Kuchling * Modules/zlibmodule.c: Add an .unused_data attribute to decompressor objects. If .unused_data is not an empty string, this means that you have arrived at the end of the stream of compressed data, and the contents of .unused_data are whatever follows the compressed stream. Thu Mar 25 21:16:07 1999 Guido van Rossum * Python/bltinmodule.c: Patch by Nick and Stephanie Lockwood to implement complex() with a string argument. This closes TODO item 2.19. Wed Mar 24 19:09:00 1999 Guido van Rossum * Tools/webchecker/wcnew.py: Added Samuel Bayer's new webchecker. Unfortunately his code breaks wcgui.py in a way that's not easy to fix. I expect that this is a temporary situation -- eventually Sam's changes will be merged back in. (The changes add a -t option to specify exceptions to the -x option, and explicit checking for #foo style fragment ids.) * Objects/dictobject.c: Vladimir Marangozov contributed updated comments. * Objects/bufferobject.c: Folded long lines. * Lib/test/output/test_sha, Lib/test/test_sha.py: Added Jeremy's test code for the sha module. * Modules/shamodule.c, Modules/Setup.in: Added Greg Stein and Andrew Kuchling's sha module. Fix comments about zlib version and URL. * Lib/test/test_bsddb.py: Remove the temp file when we're done. * Include/pythread.h: Conform to standard boilerplate. * configure.in, configure, BeOS/linkmodule, BeOS/ar-fake: Chris Herborth: the new compiler in R4.1 needs some new options to work... * Modules/socketmodule.c: Implement two suggestions by Jonathan Giddy: (1) in AIX, clear the data struct before calling gethostby{name,addr}_r(); (2) ignore the 3/5/6 args determinations made by the configure script and switch on platform identifiers instead: AIX, OSF have 3 args Sun, SGI have 5 args Linux has 6 args On all other platforms, undef HAVE_GETHOSTBYNAME_R altogether. * Modules/socketmodule.c: Vladimir Marangozov implements the AIX 3-arg gethostbyname_r code. * Lib/mailbox.py: Add readlines() to _Subfile class. Not clear who would need it, but Chris Lawrence sent me a broken version; this one is a tad simpler and more conforming to the standard. Tue Mar 23 23:05:34 1999 Jeremy Hylton * Lib/gzip.py: use struct instead of bit-manipulate in Python Tue Mar 23 19:00:55 1999 Guido van Rossum * Modules/Makefile.pre.in: Add $(EXE) to various occurrences of python so it will work on Cygwin with egcs (after setting EXE=.exe). Patch by Norman Vine. * configure, configure.in: Ack! It never defined HAVE_GETHOSTBYNAME_R so that code was never tested! Mon Mar 22 22:25:39 1999 Guido van Rossum * Include/thread.h: Adding thread.h -- unused but for b/w compatibility. As requested by Bill Janssen. * configure.in, configure: Add code to test for all sorts of gethostbyname_r variants, donated by David Arnold. * config.h.in, acconfig.h: Add symbols for gethostbyname_r variants (sigh). * Modules/socketmodule.c: Clean up pass for the previous patches. - Use HAVE_GETHOSTBYNAME_R_6_ARG instead of testing for Linux and glibc2. - If gethostbyname takes 3 args, undefine HAVE_GETHOSTBYNAME_R -- don't know what code should be used. - New symbol USE_GETHOSTBYNAME_LOCK defined iff the lock should be used. - Modify the gethostbyaddr() code to also hold on to the lock until after it is safe to release, overlapping with the Python lock. (Note: I think that it could in theory be possible that Python code executed while gethostbyname_lock is held could attempt to reacquire the lock -- e.g. in a signal handler or destructor. I will simply say "don't do that then.") * Modules/socketmodule.c: Jonathan Giddy writes: Here's a patch to fix the race condition, which wasn't fixed by Rob's patch. It holds the gethostbyname lock until the results are copied out, which means that this lock and the Python global lock are held at the same time. This shouldn't be a problem as long as the gethostbyname lock is always acquired when the global lock is not held. Mon Mar 22 19:25:30 1999 Andrew Kuchling * Modules/zlibmodule.c: Fixed the flush() method of compression objects; the test for the end of loop was incorrect, and failed when the flushmode != Z_FINISH. Logic cleaned up and commented. * Lib/test/test_zlib.py: Added simple test for the flush() method of compression objects, trying the different flush values Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FULL_FLUSH. Mon Mar 22 15:28:08 1999 Guido van Rossum * Lib/shlex.py: Bug reported by Tobias Thelen: missing "self." in assignment target. Fri Mar 19 21:50:11 1999 Guido van Rossum * Modules/arraymodule.c: Use an unsigned cast to avoid a warning in VC++. * Lib/dospath.py, Lib/ntpath.py: New code for split() by Tim Peters, behaves more like posixpath.split(). * Objects/floatobject.c: Fix a problem with Vladimir's PyFloat_Fini code: clear the free list; if a block cannot be freed, add its free items back to the free list. This is necessary to avoid leaking when Python is reinitialized later. * Objects/intobject.c: Fix a problem with Vladimir's PyInt_Fini code: clear the free list; if a block cannot be freed, add its free items back to the free list, and add its valid ints back to the small_ints array if they are in range. This is necessary to avoid leaking when Python is reinitialized later. * Lib/types.py: Added BufferType, the type returned by the new builtin buffer(). Greg Stein. * Python/bltinmodule.c: New builtin buffer() creates a derived read-only buffer from any object that supports the buffer interface (e.g. strings, arrays). * Objects/bufferobject.c: Added check for negative offset for PyBuffer_FromObject and check for negative size for PyBuffer_FromMemory. Greg Stein. Thu Mar 18 15:10:44 1999 Guido van Rossum * Lib/urlparse.py: Sjoerd Mullender writes: If a filename on Windows starts with \\, it is converted to a URL which starts with ////. If this URL is passed to urlparse.urlparse you get a path that starts with // (and an empty netloc). If you pass the result back to urlparse.urlunparse, you get a URL that starts with //, which is parsed differently by urlparse.urlparse. The fix is to add the (empty) netloc with accompanying slashes if the path in urlunparse starts with //. Do this for all schemes that use a netloc. * Lib/nturl2path.py: Sjoerd Mullender writes: Pathnames of files on other hosts in the same domain (\\host\path\to\file) are not translated correctly to URLs and back. The URL should be something like file:////host/path/to/file. Note that a combination of drive letter and remote host is not possible. Wed Mar 17 22:30:10 1999 Guido van Rossum * Lib/urlparse.py: Delete non-standard-conforming code in urljoin() that would use the netloc from the base url as the default netloc for the resulting url even if the schemes differ. Once upon a time, when the web was wild, this was a valuable hack because some people had a URL referencing an ftp server colocated with an http server without having the host in the ftp URL (so they could replicate it or change the hostname easily). More recently, after the file: scheme got added back to the list of schemes that accept a netloc, it turns out that this caused weirdness when joining an http: URL with a file: URL -- the resulting file: URL would always inherit the host from the http: URL because the file: scheme supports a netloc but in practice never has one. There are two reasons to get rid of the old, once-valuable hack, instead of removing the file: scheme from the uses_netloc list. One, the RFC says that file: uses the netloc syntax, and does not endorse the old hack. Two, neither netscape 4.5 nor IE 4.0 support the old hack. * Include/ceval.h, Include/abstract.h: Add DLL level b/w compat for PySequence_In and PyEval_CallObject Tue Mar 16 21:54:50 1999 Guido van Rossum * Lib/lib-tk/Tkinter.py: Bug reported by Jim Robinson: An attempt to execute grid_slaves with arguments (0,0) results in *all* of the slaves being returned, not just the slave associated with row 0, column 0. This is because the test for arguments in the method does not test to see if row (and column) does not equal None, but rather just whether is evaluates to non-false. A value of 0 fails this test. Tue Mar 16 14:17:48 1999 Fred Drake * Modules/cmathmodule.c: Docstring fix: acosh() returns the hyperbolic arccosine, not the hyperbolic cosine. Problem report via David Ascher by one of his students. Mon Mar 15 21:40:59 1999 Guido van Rossum * configure.in: Should test for gethost*by*name_r, not for gethostname_r (which doesn't exist and doesn't make sense). * Modules/socketmodule.c: Patch by Rob Riggs for Linux -- glibc2 has a different argument converntion for gethostbyname_r() etc. than Solaris! * Python/thread_pthread.h: Rob Riggs wrote: """ Spec says that on success pthread_create returns 0. It does not say that an error code will be < 0. Linux glibc2 pthread_create() returns ENOMEM (12) when one exceed process limits. (It looks like it should return EAGAIN, but that's another story.) For reference, see: http://www.opengroup.org/onlinepubs/7908799/xsh/pthread_create.html """ [I have a feeling that similar bugs were fixed before; perhaps someone could check that all error checks no check for != 0?] * Tools/bgen/bgen/bgenObjectDefinition.py: New mixin class that defines cmp and hash that use the ob_itself pointer. This allows (when using the mixin) different Python objects pointing to the same C object and behaving well as dictionary keys. Or so sez Jack Jansen... * Lib/urllib.py: Yet another patch by Sjoerd Mullender: Don't convert URLs to URLs using pathname2url. Fri Mar 12 22:15:43 1999 Guido van Rossum * Lib/cmd.py: Patch by Michael Scharf. He writes: The module cmd requires for each do_xxx command a help_xxx function. I think this is a little old fashioned. Here is a patch: use the docstring as help if no help_xxx function can be found. [I'm tempted to rip out all the help_* functions from pdb, but I'll resist it. Any takers? --Guido] * Tools/freeze/freeze.py: Bug submitted by Wayne Knowles, who writes: Under Windows, python freeze.py -o hello hello.py creates all the correct files in the hello subdirectory, but the Makefile has the directory prefix in it for frozen_extensions.c nmake fails because it tries to locate hello/frozen_extensions.c (His fix adds a call to os.path.basename() in the appropriate place.) * Objects/floatobject.c, Objects/intobject.c: Vladimir has restructured his code somewhat so that the blocks are now represented by an explicit structure. (There are still too many casts in the code, but that may be unavoidable.) Also added code so that with -vv it is very chatty about what it does. * Demo/zlib/zlibdemo.py, Demo/zlib/minigzip.py: Change #! line to modern usage; also chmod +x * Demo/pdist/rrcs, Demo/pdist/rcvs, Demo/pdist/rcsbump: Change #! line to modern usage * Lib/nturl2path.py, Lib/urllib.py: From: Sjoerd Mullender The filename to URL conversion didn't properly quote special characters. The URL to filename didn't properly unquote special chatacters. * Objects/floatobject.c: OK, try again. Vladimir gave me a fix for the alignment bus error, so here's his patch again. This time it works (at least on Solaris, Linux and Irix). Thu Mar 11 23:21:23 1999 Guido van Rossum * Tools/idle/PathBrowser.py: Don't crash when sys.path contains an empty string. * Tools/idle/PathBrowser.py: - Don't crash in the case where a superclass is a string instead of a pyclbr.Class object; this can happen when the superclass is unrecognizable (to pyclbr), e.g. when module renaming is used. - Show a watch cursor when calling pyclbr (since it may take a while recursively parsing imported modules!). Thu Mar 11 16:04:04 1999 Fred Drake * Lib/mimetypes.py: Added .rdf and .xsl as application/xml types. (.rdf is for the Resource Description Framework, a metadata encoding, and .xsl is for the Extensible Stylesheet Language.) Thu Mar 11 13:26:23 1999 Guido van Rossum * Lib/test/output/test_popen2, Lib/test/test_popen2.py: Test for popen2 module, by Chris Tismer. * Objects/floatobject.c: Alas, Vladimir's patch caused a bus error (probably double alignment?), and I didn't test it. Withdrawing it for now. Wed Mar 10 22:55:47 1999 Guido van Rossum * Objects/floatobject.c: Patch by Vladimir Marangoz to allow freeing of the allocated blocks of floats on finalization. * Objects/intobject.c: Patch by Vladimir Marangoz to allow freeing of the allocated blocks of integers on finalization. * Tools/idle/EditorWindow.py, Tools/idle/Bindings.py: Add PathBrowser to File module * Tools/idle/PathBrowser.py: "Path browser" - 4 scrolled lists displaying: directories on sys.path modules in selected directory classes in selected module methods of selected class Sinlge clicking in a directory, module or class item updates the next column with info about the selected item. Double clicking in a module, class or method item opens the file (and selects the clicked item if it is a class or method). I guess eventually I should be using a tree widget for this, but the ones I've seen don't work well enough, so for now I use the old Smalltalk or NeXT style multi-column hierarchical browser. * Tools/idle/MultiScrolledLists.py: New utility: multiple scrolled lists in parallel * Tools/idle/ScrolledList.py: - White background. - Display "(None)" (or text of your choosing) when empty. - Don't set the focus. Tue Mar 9 19:31:21 1999 Guido van Rossum * Lib/urllib.py: open_http also had the 'data is None' test backwards. don't call with the extra argument if data is None. * Demo/embed/demo.c: Call Py_SetProgramName() instead of redefining getprogramname(), reflecting changes in the runtime around 1.5 or earlier. * Python/ceval.c: Always test for an error return (usually NULL or -1) without setting an exception. * Modules/timemodule.c: Patch by Chris Herborth for BeOS code. He writes: I had an off-by-1000 error in floatsleep(), and the problem with time.clock() is that it's not implemented properly on QNX... ANSI says it's supposed to return _CPU_ time used by the process, but on QNX it returns the amount of real time used... so I was confused. * Tools/bgen/bgen/macsupport.py: Small change by Jack Jansen. Test for self.returntype behaving like OSErr rather than being it. Thu Feb 25 16:14:58 1999 Jeremy Hylton * Lib/urllib.py: http_error had the 'data is None' test backwards. don't call with the extra argument if data is None. * Lib/urllib.py: change indentation from 8 spaces to 4 spaces * Lib/urllib.py: pleasing the tabnanny Thu Feb 25 14:26:02 1999 Fred Drake * Lib/colorsys.py: Oops, one more "x, y, z" to convert... * Lib/colorsys.py: Adjusted comment at the top to be less confusing, following Fredrik Lundh's example. Converted comment to docstring. Wed Feb 24 18:49:15 1999 Fred Drake * Lib/toaiff.py: Use sndhdr instead of the obsolete whatsound module. Wed Feb 24 18:42:38 1999 Jeremy Hylton * Lib/urllib.py: When performing a POST request, i.e. when the second argument to urlopen is used to specify form data, make sure the second argument is threaded through all of the http_error_NNN calls. This allows error handlers like the redirect and authorization handlers to properly re-start the connection. Wed Feb 24 16:25:17 1999 Guido van Rossum * Lib/mhlib.py: Patch by Lars Wirzenius: o the initial comment is wrong: creating messages is already implemented o Message.getbodytext: if the mail or it's part contains an empty content-transfer-encoding header, the code used to break; the change below treats an empty encoding value the same as the other types that do not need decoding o SubMessage.getbodytext was missing the decode argument; the change below adds it; I also made it unconditionally return the raw text if decoding was not desired, because my own routines needed that (and it was easier than rewriting my own routines ;-) Wed Feb 24 00:35:43 1999 Barry Warsaw * Python/bltinmodule.c (initerrors): Make sure that the exception tuples ("base-classes" when string-based exceptions are used) reflect the real class hierarchy, i.e. that SystemExit derives from Exception not StandardError. * Lib/exceptions.py: Document the correct class hierarchy for SystemExit. It is not an error and so it derives from Exception and not SystemError. The docstring was incorrect but the implementation was fine. Tue Feb 23 23:07:51 1999 Guido van Rossum * Lib/shutil.py: Add import sys, needed by reference to sys.exc_info() in rmtree(). Discovered by Mitch Chapman. * config.h.in: Now that we don't have AC_CHECK_LIB(m, pow), the HAVE_LIBM symbol disappears. It wasn't used anywhere anyway... * Modules/arraymodule.c: Carefully check for overflow when allocating the memory for fromfile -- someone tried to pass in sys.maxint and got bitten by the bogus calculations. * configure.in: Get rid of AC_CHECK_LIB(m, pow) since this is taken care of later with LIBM (from --with-libm=...); this actually broke the customizability offered by the latter option. Thanks go to Clay Spence for reporting this. * Lib/test/test_dl.py: 1. Print the error message (carefully) when a dl.open() fails in verbose mode. 2. When no test case worked, raise ImportError instead of failing. * Python/bltinmodule.c: Patch by Tim Peters to improve the range checks for range() and xrange(), especially for platforms where int and long are different sizes (so sys.maxint isn't actually the theoretical limit for the length of a list, but the largest C int is -- sys.maxint is the largest Python int, which is actually a C long). * Makefile.in: 1. Augment the DG/UX rule so it doesn't break the BeOS build. 2. Add $(EXE) to various occurrences of python so it will work on Cygwin with egcs (after setting EXE=.exe). These patches by Norman Vine. * Lib/posixfile.py: According to Jeffrey Honig, bsd/os 2.0 - 4.0 should be added to the list (of bsd variants that have a different lock structure). * Lib/test/test_fcntl.py: According to Jeffrey Honig, bsd/os 4.0 should be added to the list. * Modules/timemodule.c: Patch by Tadayoshi Funaba (with some changes) to be smarter about guessing what happened when strftime() returns 0. Is it buffer overflow or was the result simply 0 bytes long? (This happens for an empty format string, or when the format string is a single %Z and the timezone is unknown.) if the buffer is at least 256 times as long as the format, assume the latter. Mon Feb 22 19:01:42 1999 Guido van Rossum * Lib/urllib.py: As Des Barry points out, we need to call pathname2url(file) in two calls to addinfourl() in open_file(). * Modules/Setup.in: Document *static* -- in two places! * Modules/timemodule.c: We don't support leap seconds, so the seconds field of a time 9-tuple should be in the range [0-59]. Noted by Tadayoshi Funaba. * Modules/stropmodule.c: In atoi(), don't use isxdigit() to test whether the last character converted was a "digit" -- use isalnum(). This test is there only to guard against "+" or "-" being interpreted as a valid int literal. Reported by Takahiro Nakayama. * Lib/os.py: As Finn Bock points out, _P_WAIT etc. don't have a leading underscore so they don't need to be treated specially here. Mon Feb 22 15:38:58 1999 Fred Drake * Misc/NEWS: Typo: "apparentlt" --> "apparently" Mon Feb 22 15:38:46 1999 Guido van Rossum * Lib/urlparse.py: Steve Clift pointed out that 'file' allows a netloc. * Modules/posixmodule.c: The docstring for ttyname(..) claims a second "mode" argument. The actual code does not allow such an argument. (Finn Bock.) * Lib/lib-old/poly.py: Dang. Even though this is obsolete code, somebody found a bug, and I fix it. Oh well. Thu Feb 18 20:51:50 1999 Fred Drake * Lib/pyclbr.py: Bow to font-lock at the end of the docstring, since it throws stuff off. Make sure the path paramter to readmodule() is a list before adding it with sys.path, or the addition could fail. ====================================================================== From 1.5.2b1 to 1.5.2b2 ======================= General ------- - Many memory leaks fixed. - Many small bugs fixed. - Command line option -OO (or -O -O) suppresses inclusion of doc strings in resulting bytecode. Windows-specific changes ------------------------ - New built-in module winsound provides an interface to the Win32 PlaySound() call. - Re-enable the audioop module in the config.c file. - On Windows, support spawnv() and associated P_* symbols. - Fixed the conversion of times() return values on Windows. - Removed freeze from the installer -- it doesn't work without the source tree. (See FAQ 8.11.) - On Windows 95/98, the Tkinter module now is smart enough to find Tcl/Tk even when the PATH environment variable hasn't been set -- when the import of _tkinter fails, it searches in a standard locations, patches os.environ["PATH"], and tries again. When it still fails, a clearer error message is produced. This should avoid most installation problems with Tkinter use (e.g. in IDLE). - The -i option doesn't make any calls to set[v]buf() for stdin -- this apparently screwed up _kbhit() and the _tkinter main loop. - The ntpath module (and hence, os.path on Windows) now parses out UNC paths (e.g. \\host\mountpoint\dir\file) as "drive letters", so that splitdrive() will \\host\mountpoint as the drive and \dir\file as the path. ** EXPERIMENTAL ** - Added a hack to the exit code so that if (1) the exit status is nonzero and (2) we think we have our own DOS box (i.e. we're not started from a command line shell), we print a message and wait for the user to hit a key before the DOS box is closed. - Updated the installer to WISE 5.0g. Added a dialog warning about the imminent Tcl installation. Added a dialog to specify the program group name in the start menu. Upgraded the Tcl installer to Tcl 8.0.4. Changes to intrinsics --------------------- - The repr() or str() of a module object now shows the __file__ attribute (i.e., the file which it was loaded), or the string "(built-in)" if there is no __file__ attribute. - The range() function now avoids overflow during its calculations (if at all possible). - New info string sys.hexversion, which is an integer encoding the version in hexadecimal. In other words, hex(sys.hexversion) == 0x010502b2 for Python 1.5.2b2. New or improved ports --------------------- - Support for Nextstep descendants (future Mac systems). - Improved BeOS support. - Support dynamic loading of shared libraries on NetBSD platforms that use ELF (i.e., MIPS and Alpha systems). Configuration/build changes --------------------------- - The Lib/test directory is no longer included in the default module search path (sys.path) -- "test" has been a package ever since 1.5. - Now using autoconf 2.13. New library modules ------------------- - New library modules asyncore and asynchat: these form Sam Rushing's famous asynchronous socket library. Sam has gracefully allowed me to incorporate these in the standard Python library. - New module statvfs contains indexing constants for [f]statvfs() return tuple. Changes to the library ---------------------- - The wave module (platform-independent support for Windows sound files) has been fixed to actually make it work. - The sunau module (platform-independent support for Sun/NeXT sound files) has been fixed to work across platforms. Also, a weird encoding bug in the header of the audio test data file has been corrected. - Fix a bug in the urllib module that occasionally tripped up webchecker and other ftp retrieves. - ConfigParser's get() method now accepts an optional keyword argument (vars) that is substituted on top of the defaults that were setup in __init__. You can now also have recusive references in your configuration file. - Some improvements to the Queue module, including a put_nowait() module and an optional "block" second argument, to get() and put(), defaulting to 1. - The updated xmllib module is once again compatible with the version present in Python 1.5.1 (this was accidentally broken in 1.5.2b1). - The bdb module (base class for the debugger) now supports canonicalizing pathnames used in breakpoints. The derived class must override the new canonical() method for this to work. Also changed clear_break() to the backwards compatible old signature, and added clear_bpbynumber() for the new functionality. - In sgmllib (and hence htmllib), recognize attributes even if they don't have space in front of them. I.e. '' will now have two attributes recognized. - In the debugger (pdb), change clear syntax to support three alternatives: clear; clear file:line; clear bpno bpno ... - The os.path module now pretends to be a submodule within the os "package", so you can do things like "from os.path import exists". - The standard exceptions now have doc strings. - In the smtplib module, exceptions are now classes. Also avoid inserting a non-standard space after "TO" in rcpt() command. - The rfc822 module's getaddrlist() method now uses all occurrences of the specified header instead of just the first. Some other bugfixes too (to handle more weird addresses found in a very large test set, and to avoid crashes on certain invalid dates), and a small test module has been added. - Fixed bug in urlparse in the common-case code for HTTP URLs; it would lose the query, fragment, and/or parameter information. - The sndhdr module no longer supports whatraw() -- it depended on a rare extenral program. - The UserList module/class now supports the extend() method, like real list objects. - The uu module now deals better with trailing garbage generated by some broke uuencoders. - The telnet module now has an my_interact() method which uses threads instead of select. The interact() method uses this by default on Windows (where the single-threaded version doesn't work). - Add a class to mailbox.py for dealing with qmail directory mailboxes. The test code was extended to notice these being used as well. Changes to extension modules ---------------------------- - Support for the [f]statvfs() system call, where it exists. - Fixed some bugs in cPickle where bad input could cause it to dump core. - Fixed cStringIO to make the writelines() function actually work. - Added strop.expandtabs() so string.expandtabs() is now much faster. - Added fsync() and fdatasync(), if they appear to exist. - Support for "long files" (64-bit seek pointers). - Fixed a bug in the zlib module's flush() function. - Added access() system call. It returns 1 if access granted, 0 if not. - The curses module implements an optional nlines argument to w.scroll(). (It then calls wscrl(win, nlines) instead of scoll(win).) Changes to tools ---------------- - Some changes to IDLE; see Tools/idle/NEWS.txt. - Latest version of Misc/python-mode.el included. Changes to Tkinter ------------------ - Avoid tracebacks when an image is deleted after its root has been destroyed. Changes to the Python/C API --------------------------- - When parentheses are used in a PyArg_Parse[Tuple]() call, any sequence is now accepted, instead of requiring a tuple. This is in line with the general trend towards accepting arbitrary sequences. - Added PyModule_GetFilename(). - In PyNumber_Power(), remove unneeded and even harmful test for float to the negative power (which is already and better done in floatobject.c). - New version identification symbols; read patchlevel.h for info. The version numbers are now exported by Python.h. - Rolled back the API version change -- it's back to 1007! - The frozenmain.c function calls PyInitFrozenExtensions(). - Added 'N' format character to Py_BuildValue -- like 'O' but doesn't INCREF. ====================================================================== From 1.5.2a2 to 1.5.2b1 ======================= Changes to intrinsics --------------------- - New extension NotImplementedError, derived from RuntimeError. Not used, but recommended use is for "abstract" methods to raise this. - The parser will now spit out a warning or error when -t or -tt is used for parser input coming from a string, too. - The code generator now inserts extra SET_LINENO opcodes when compiling multi-line argument lists. - When comparing bound methods, use identity test on the objects, not equality test. New or improved ports --------------------- - Chris Herborth has redone his BeOS port; it now works on PowerPC (R3/R4) and x86 (R4 only). Threads work too in this port. Renaming -------- - Thanks to Chris Herborth, the thread primitives now have proper Py* names in the source code (they already had those for the linker, through some smart macros; but the source still had the old, un-Py names). Configuration/build changes --------------------------- - Improved support for FreeBSD/3. - Check for pthread_detach instead of pthread_create in libc. - The makesetup script now searches EXECINCLUDEPY before INCLUDEPY. - Misc/Makefile.pre.in now also looks at Setup.thread and Setup.local. Otherwise modules such as thread didn't get incorporated in extensions. New library modules ------------------- - shlex.py by Eric Raymond provides a lexical analyzer class for simple shell-like syntaxes. - netrc.py by Eric Raymond provides a parser for .netrc files. (The undocumented Netrc class in ftplib.py is now obsolete.) - codeop.py is a new module that contains the compile_command() function that was previously in code.py. This is so that JPython can provide its own version of this function, while still sharing the higher-level classes in code.py. - turtle.py is a new module for simple turtle graphics. I'm still working on it; let me know if you use this to teach Python to children or other novices without prior programming experience. Obsoleted library modules ------------------------- - poly.py and zmod.py have been moved to Lib/lib-old to emphasize their status of obsoleteness. They don't do a particularly good job and don't seem particularly relevant to the Python core. New tools --------- - I've added IDLE: my Integrated DeveLopment Environment for Python. Requires Tcl/Tk (and Tkinter). Works on Windows and Unix (and should work on Macintosh, but I haven't been able to test it there; it does depend on new features in 1.5.2 and perhaps even new features in 1.5.2b1, especially the new code module). This is very much a work in progress. I'd like to hear how people like it compared to PTUI (or any other IDE they are familiar with). - New tools by Barry Warsaw: = audiopy: controls the Solaris Audio device = pynche: The PYthonically Natural Color and Hue Editor = world: Print mappings between country names and DNS country codes New demos --------- - Demo/scripts/beer.py prints the lyrics to an arithmetic drinking song. - Demo/tkinter/guido/optionmenu.py shows how to do an option menu in Tkinter. (By Fredrik Lundh -- not by me!) Changes to the library ---------------------- - compileall.py now avoids recompiling .py files that haven't changed; it adds a -f option to force recompilation. - New version of xmllib.py by Sjoerd Mullender (0.2 with latest patches). - nntplib.py: statparse() no longer lowercases the message-id. - types.py: use type(__stdin__) for FileType. - urllib.py: fix translations for filenames with "funny" characters. Patch by Sjoerd Mullender. Note that if you subclass one of the URLopener classes, and you have copied code from the old urllib.py, your subclass may stop working. A long-term solution is to provide more methods so that you don't have to copy code. - cgi.py: In read_multi, allow a subclass to override the class we instantiate when we create a recursive instance, by setting the class variable 'FieldStorageClass' to the desired class. By default, this is set to None, in which case we use self.__class__ (as before). Also, a patch by Jim Fulton to pass additional arguments to recursive calls to the FieldStorage constructor from its read_multi method. - UserList.py: In __getslice__, use self.__class__ instead of UserList. - In SimpleHTTPServer.py, the server specified in test() should be BaseHTTPServer.HTTPServer, in case the request handler should want to reference the two attributes added by BaseHTTPServer.server_bind. (By Jeff Rush, for Bobo). Also open the file in binary mode, so serving images from a Windows box might actually work. - In CGIHTTPServer.py, the list of acceptable formats is -split- on spaces but -joined- on commas, resulting in double commas in the joined text. (By Jeff Rush.) - SocketServer.py, patch by Jeff Bauer: a minor change to declare two new threaded versions of Unix Server classes, using the ThreadingMixIn class: ThreadingUnixStreamServer, ThreadingUnixDatagramServer. - bdb.py: fix bomb on deleting a temporary breakpoint: there's no method do_delete(); do_clear() was meant. By Greg Ward. - getopt.py: accept a non-list sequence for the long options (request by Jack Jansen). Because it might be a common mistake to pass a single string, this situation is treated separately. Also added docstrings (copied from the library manual) and removed the (now redundant) module comments. - tempfile.py: improvements to avoid security leaks. - code.py: moved compile_command() to new module codeop.py. - pickle.py: support pickle format 1.3 (binary float added). By Jim Fulton. Also get rid of the undocumented obsolete Pickler dump_special method. - uu.py: Move 'import sys' to top of module, as noted by Tim Peters. - imaplib.py: fix problem with some versions of IMAP4 servers that choose to mix the case in their CAPABILITIES response. - cmp.py: use (f1, f2) as cache key instead of f1 + ' ' + f2. Noted by Fredrik Lundh. Changes to extension modules ---------------------------- - More doc strings for several modules were contributed by Chris Petrilli: math, cmath, fcntl. - Fixed a bug in zlibmodule.c that could cause core dumps on decompression of rarely occurring input. - cPickle.c: new version from Jim Fulton, with Open Source copyright notice. Also, initialize self->safe_constructors early on to prevent crash in early dealloc. - cStringIO.c: new version from Jim Fulton, with Open Source copyright notice. Also fixed a core dump in cStringIO.c when doing seeks. - mpzmodule.c: fix signed character usage in mpz.mpz(stringobjecty). - readline.c: Bernard Herzog pointed out that rl_parse_and_bind modifies its argument string (bad function!), so we make a temporary copy. - sunaudiodev.c: Barry Warsaw added more smarts to get the device and control pseudo-device, per audio(7I). Changes to tools ---------------- - New, improved version of Barry Warsaw's Misc/python-mode.el (editing support for Emacs). - tabnanny.py: added a -q ('quiet') option to tabnanny, which causes only the names of offending files to be printed. - freeze: when printing missing modules, also print the module they were imported from. - untabify.py: patch by Detlef Lannert to implement -t option (set tab size). Changes to Tkinter ------------------ - grid_bbox(): support new Tk API: grid bbox ?column row? ?column2 row2? - _tkinter.c: RajGopal Srinivasan noted that the latest code (1.5.2a2) doesn't work when running in a non-threaded environment. He added some #ifdefs that fix this. Changes to the Python/C API --------------------------- - Bumped API version number to 1008 -- enough things have changed! - There's a new macro, PyThreadState_GET(), which does the same work as PyThreadState_Get() without the overhead of a function call (it also avoids the error check). The two top calling locations of PyThreadState_Get() have been changed to use this macro. - All symbols intended for export from a DLL or shared library are now marked as such (with the DL_IMPORT() macro) in the header file that declares them. This was needed for the BeOS port, and should also make some other ports easier. The PC port no longer needs the file with exported symbols (PC/python_nt.def). There's also a DL_EXPORT macro which is only used for init methods in extension modules, and for Py_Main(). Invisible changes to internals ------------------------------ - Fixed a bug in new_buffersize() in fileobject.c which could return a buffer size that was way too large. - Use PySys_WriteStderr instead of fprintf in most places. - dictobject.c: remove dead code discovered by Vladimir Marangozov. - tupleobject.c: make tuples less hungry -- an extra item was allocated but never used. Tip by Vladimir Marangozov. - mymath.h: Metrowerks PRO4 finally fixes the hypot snafu. (Jack Jansen) - import.c: Jim Fulton fixes a reference count bug in PyEval_GetGlobals. - glmodule.c: check in the changed version after running the stubber again -- this solves the conflict with curses over the 'clear' entry point much nicer. (Jack Jansen had checked in the changes to cstubs eons ago, but I never regenrated glmodule.c :-( ) - frameobject.c: fix reference count bug in PyFrame_New. Vladimir Marangozov. - stropmodule.c: add a missing DECREF in an error exit. Submitted by Jonathan Giddy. ====================================================================== From 1.5.2a1 to 1.5.2a2 ======================= General ------- - It is now a syntax error to have a function argument without a default following one with a default. - __file__ is now set to the .py file if it was parsed (it used to always be the .pyc/.pyo file). - Don't exit with a fatal error during initialization when there's a problem with the exceptions.py module. - New environment variable PYTHONOPTIMIZE can be used to set -O. - New version of python-mode.el for Emacs. Miscellaneous fixed bugs ------------------------ - No longer print the (confusing) error message about stack underflow while compiling. - Some threading and locking bugs fixed. - When errno is zero, report "Error", not "Success". Documentation ------------- - Documentation will be released separately. - Doc strings added to array and md5 modules by Chris Petrilli. Ports and build procedure ------------------------- - Stop installing when a move or copy fails. - New version of the OS/2 port code by Jeff Rush. - The makesetup script handles absolute filenames better. - The 'new' module is now enabled by default in the Setup file. - I *think* I've solved the problem with the Linux build blowing up sometimes due to a conflict between sigcheck/intrcheck and signalmodule. Built-in functions ------------------ - The second argument to apply() can now be any sequence, not just a tuple. Built-in types -------------- - Lists have a new method: L1.extend(L2) is equivalent to the common idiom L1[len(L1):] = L2. - Better error messages when a sequence is indexed with a non-integer. - Bettter error message when calling a non-callable object (include the type in the message). Python services --------------- - New version of cPickle.c fixes some bugs. - pickle.py: improved instantiation error handling. - code.py: reworked quite a bit. New base class InteractiveInterpreter and derived class InteractiveConsole. Fixed several problems in compile_command(). - py_compile.py: print error message and continue on syntax errors. Also fixed an old bug with the fstat code (it was never used). - pyclbr.py: support submodules of packages. String Services --------------- - StringIO.py: raise the right exception (ValueError) for attempted I/O on closed StringIO objects. - re.py: fixed a bug in subn(), which caused .groups() to fail inside the replacement function called by sub(). - The struct module has a new format 'P': void * in native mode. Generic OS Services ------------------- - Module time: Y2K robustness. 2-digit year acceptance depends on value of time.accept2dyear, initialized from env var PYTHONY2K, default 0. Years 00-68 mean 2000-2068, while 69-99 mean 1969-1999 (POSIX or X/Open recommendation). - os.path: normpath(".//x") should return "x", not "/x". - getpass.py: fall back on default_getpass() when sys.stdin.fileno() doesn't work. - tempfile.py: regenerate the template after a fork() call. Optional OS Services -------------------- - In the signal module, disable restarting interrupted system calls when we have siginterrupt(). Debugger -------- - No longer set __args__; this feature is no longer supported and can affect the debugged code. - cmd.py, pdb.py and bdb.py have been overhauled by Richard Wolff, who added aliases and some other useful new features, e.g. much better breakpoint support: temporary breakpoint, disabled breakpoints, breakpoints with ignore counts, and conditions; breakpoints can be set on a file before it is loaded. Profiler -------- - Changes so that JPython can use it. Also fix the calibration code so it actually works again . Internet Protocols and Support ------------------------------ - imaplib.py: new version from Piers Lauder. - smtplib.py: change sendmail() method to accept a single string or a list or strings as the destination (commom newbie mistake). - poplib.py: LIST with a msg argument fixed. - urlparse.py: some optimizations for common case (http). - urllib.py: support content-length in info() for ftp protocol; support for a progress meter through a third argument to urlretrieve(); commented out gopher test (the test site is dead). Internet Data handling ---------------------- - sgmllib.py: support tags with - or . in their name. - mimetypes.py: guess_type() understands 'data' URLs. Restricted Execution -------------------- - The classes rexec.RModuleLoader and rexec.RModuleImporter no longer exist. Tkinter ------- - When reporting an exception, store its info in sys.last_*. Also, write all of it to stderr. - Added NS, EW, and NSEW constants, for grid's sticky option. - Fixed last-minute bug in 1.5.2a1 release: need to include "mytime.h". - Make bind variants without a sequence return a tuple of sequences (formerly it returned a string, which wasn't very convenient). - Add image commands to the Text widget (these are new in Tk 8.0). - Added new listbox and canvas methods: {xview,yview}_{scroll,moveto}.) - Improved the thread code (but you still can't call update() from another thread on Windows). - Fixed unnecessary references to _default_root in the new dialog modules. - Miscellaneous problems fixed. Windows General --------------- - Call LoadLibraryEx(..., ..., LOAD_WITH_ALTERED_SEARCH_PATH) to search for dependent dlls in the directory containing the .pyd. - In debugging mode, call DebugBreak() in Py_FatalError(). Windows Installer ----------------- - Install zlib.dll in the DLLs directory instead of in the win32 system directory, to avoid conflicts with other applications that have their own zlib.dll. Test Suite ---------- - test_long.py: new test for long integers, by Tim Peters. - regrtest.py: improved so it can be used for other test suites as well. - test_strftime.py: use re to compare test results, to support legal variants (e.g. on Linux). Tools and Demos --------------- - Four new scripts in Tools/scripts: crlf.py and lfcr.py (to remove/add Windows style '\r\n' line endings), untabify.py (to remove tabs), and rgrep.yp (reverse grep). - Improvements to Tools/freeze/. Each Python module is now written to its own C file. This prevents some compilers or assemblers from blowing up on large frozen programs, and saves recompilation time if only a few modules are changed. Other changes too, e.g. new command line options -x and -i. - Much improved (and smaller!) version of Tools/scripts/mailerdaemon.py. Python/C API ------------ - New mechanism to support extensions of the type object while remaining backward compatible with extensions compiled for previous versions of Python 1.5. A flags field indicates presence of certain fields. - Addition to the buffer API to differentiate access to bytes and 8-bit characters (in anticipation of Unicode characters). - New argument parsing format t# ("text") to indicate 8-bit characters; s# simply means 8-bit bytes, for backwards compatibility. - New object type, bufferobject.c is an example and can be used to create buffers from memory. - Some support for 64-bit longs, including some MS platforms. - Many calls to fprintf(stderr, ...) have been replaced with calls to PySys_WriteStderr(...). - The calling context for PyOS_Readline() has changed: it must now be called with the interpreter lock held! It releases the lock around the call to the function pointed to by PyOS_ReadlineFunctionPointer (default PyOS_StdioReadline()). - New APIs PyLong_FromVoidPtr() and PyLong_AsVoidPtr(). - Renamed header file "thread.h" to "pythread.h". - The code string of code objects may now be anything that supports the buffer API. ====================================================================== From 1.5.1 to 1.5.2a1 ===================== General ------- - When searching for the library, a landmark that is a compiled module (string.pyc or string.pyo) is also accepted. - When following symbolic links to the python executable, use a loop so that a symlink to a symlink can work. - Added a hack so that when you type 'quit' or 'exit' at the interpreter, you get a friendly explanation of how to press Ctrl-D (or Ctrl-Z) to exit. - New and improved Misc/python-mode.el (Python mode for Emacs). - Revert a new feature in Unix dynamic loading: for one or two revisions, modules were loaded using the RTLD_GLOBAL flag. It turned out to be a bad idea. Miscellaneous fixed bugs ------------------------ - All patches on the patch page have been integrated. (But much more has been done!) - Several memory leaks plugged (e.g. the one for classes with a __getattr__ method). - Removed the only use of calloc(). This triggered an obscure bug on multiprocessor Sparc Solaris 2.6. - Fix a peculiar bug that would allow "import sys.time" to succeed (believing the built-in time module to be a part of the sys package). - Fix a bug in the overflow checking when converting a Python long to a C long (failed to convert -2147483648L, and some other cases). Documentation ------------- - Doc strings have been added to many extension modules: __builtin__, errno, select, signal, socket, sys, thread, time. Also to methods of list objects (try [].append.__doc__). A doc string on a type will now automatically be propagated to an instance if the instance has methods that are accessed in the usual way. - The documentation has been expanded and the formatting improved. (Remember that the documentation is now unbundled and has its own release cycle though; see http://www.python.org/doc/.) - Added Misc/Porting -- a mini-FAQ on porting to a new platform. Ports and build procedure ------------------------- - The BeOS port is now integrated. Courtesy Chris Herborth. - Symbol files for FreeBSD 2.x and 3.x have been contributed (Lib/plat-freebsd[23]/*). - Support HPUX 10.20 DCE threads. - Finally fixed the configure script so that (on SGI) if -OPT:Olimit=0 works, it won't also use -Olimit 1500 (which gives a warning for every file). Also support the SGI_ABI environment variable better. - The makesetup script now understands absolute pathnames ending in .o in the module -- it assumes it's a file for which we have no source. - Other miscellaneous improvements to the configure script and Makefiles. - The test suite now uses a different sound sample. Built-in functions ------------------ - Better checks for invalid input to int(), long(), string.atoi(), string.atol(). (Formerly, a sign without digits would be accepted as a legal ways to spell zero.) - Changes to map() and filter() to use the length of a sequence only as a hint -- if an IndexError happens earlier, take that. (Formerly, this was considered an error.) - Experimental feature in getattr(): a third argument can specify a default (instead of raising AttributeError). - Implement round() slightly different, so that for negative ndigits no additional errors happen in the last step. - The open() function now adds the filename to the exception when it fails. Built-in exceptions ------------------- - New standard exceptions EnvironmentError and PosixError. EnvironmentError is the base class for IOError and PosixError; PosixError is the same as os.error. All this so that either exception class can be instantiated with a third argument indicating a filename. The built-in function open() and most os/posix functions that take a filename argument now use this. Built-in types -------------- - List objects now have an experimental pop() method; l.pop() returns and removes the last item; l.pop(i) returns and removes the item at i. Also, the sort() method is faster again. Sorting is now also safer: it is impossible for the sorting function to modify the list while the sort is going on (which could cause core dumps). - Changes to comparisons: numbers are now smaller than any other type. This is done to prevent the circularity where [] < 0L < 1 < [] is true. As a side effect, cmp(None, 0) is now positive instead of negative. This *shouldn't* affect any working code, but I've found that the change caused several "sleeping" bugs to become active, so beware! - Instance methods may now have other callable objects than just Python functions as their im_func. Use new.instancemethod() or write your own C code to create them; new.instancemethod() may be called with None for the instance to create an unbound method. - Assignment to __name__, __dict__ or __bases__ of a class object is now allowed (with stringent type checks); also allow assignment to __getattr__ etc. The cached values for __getattr__ etc. are recomputed after such assignments (but not for derived classes :-( ). - Allow assignment to some attributes of function objects: func_code, func_defaults and func_doc / __doc__. (With type checks except for __doc__ / func_doc .) Python services --------------- - New tests (in Lib/test): reperf.py (regular expression benchmark), sortperf.py (list sorting benchmark), test_MimeWriter.py (test case for the MimeWriter module). - Generalized test/regrtest.py so that it is useful for testing other packages. - The ihooks.py module now understands package imports. - In code.py, add a class that subsumes Fredrik Lundh's PythonInterpreter class. The interact() function now uses this. - In rlcompleter.py, in completer(), return None instead of raising an IndexError when there are no more completions left. - Fixed the marshal module to test for certain common kinds of invalid input. (It's still not foolproof!) - In the operator module, add an alias (now the preferred name) "contains" for "sequenceincludes". String Services --------------- - In the string and strop modules, in the replace() function, treat an empty pattern as an error (since it's not clear what was meant!). - Some speedups to re.py, especially the string substitution and split functions. Also added new function/method findall(), to find all occurrences of a given substring. - In cStringIO, add better argument type checking and support the readonly 'closed' attribute (like regular files). - In the struct module, unsigned 1-2 byte sized formats no longer result in long integer values. Miscellaneous services ---------------------- - In whrandom.py, added new method and function randrange(), same as choice(range(start, stop, step)) but faster. This addresses the problem that randint() was accidentally defined as taking an inclusive range. Also, randint(a, b) is now redefined as randrange(a, b+1), adding extra range and type checking to its arguments! - Add some semi-thread-safety to random.gauss() (it used to be able to crash when invoked from separate threads; now the worst it can do is give a duplicate result occasionally). - Some restructuring and generalization done to cmd.py. - Major upgrade to ConfigParser.py; converted to using 're', added new exceptions, support underscore in section header and option name. No longer add 'name' option to every section; instead, add '__name__'. - In getpass.py, don't use raw_input() to ask for the password -- we don't want it to show up in the readline history! Also don't catch interrupts (the try-finally already does all necessary cleanup). Generic OS Services ------------------- - New functions in os.py: makedirs(), removedirs(), renames(). New variable: linesep (the line separator as found in binary files, i.e. '\n' on Unix, '\r\n' on DOS/Windows, '\r' on Mac. Do *not* use this with files opened in (default) text mode; the line separator used will always be '\n'! - Changes to the 'os.path' submodule of os.py: added getsize(), getmtime(), getatime() -- these fetch the most popular items from the stat return tuple. - In the time module, add strptime(), if it exists. (This parses a time according to a format -- the inverse of strftime().) Also, remove the call to mktime() from strftime() -- it messed up the formatting of some non-local times. - In the socket module, added a new function gethostbyname_ex(). Also, don't use #ifdef to test for some symbols that are enums on some platforms (and should exist everywhere). Optional OS Services -------------------- - Some fixes to gzip.py. In particular, the readlines() method now returns the lines *with* trailing newline characters, like readlines() of regular file objects. Also, it didn't work together with cPickle; fixed that. - In whichdb.py, support byte-swapped dbhash (bsddb) files. - In anydbm.py, look at the type of an existing database to determine which module to use to open it. (The anydbm.error exception is now a tuple.) Unix Services ------------- - In the termios module, in tcsetattr(), initialize the structure vy calling tcgetattr(). - Added some of the "wait status inspection" macros as functions to the posix module (and thus to the os module): WEXITSTATUS(), WIFEXITED(), WIFSIGNALED(), WIFSTOPPED(), WSTOPSIG(), WTERMSIG(). - In the syslog module, make the default facility more intuitive (matching the docs). Debugger -------- - In pdb.py, support for setting breaks on files/modules that haven't been loaded yet. Internet Protocols and Support ------------------------------ - Changes in urllib.py; sped up unquote() and quote(). Fixed an obscure bug in quote_plus(). Added urlencode(dict) -- convenience function for sending a POST request with urlopen(). Use the getpass module to ask for a password. Rewrote the (test) main program so that when used as a script, it can retrieve one or more URLs to stdout. Use -t to run the self-test. Made the proxy code work again. - In cgi.py, treat "HEAD" the same as "GET", so that CGI scripts don't fail when someone asks for their HEAD. Also, for POST, set the default content-type to application/x-www-form-urlencoded. Also, in FieldStorage.__init__(), when method='GET', always get the query string from environ['QUERY_STRING'] or sys.argv[1] -- ignore an explicitly passed in fp. - The smtplib.py module now supports ESMTP and has improved standard compliance, for picky servers. - Improved imaplib.py. - Fixed UDP support in SocketServer.py (it never worked). - Fixed a small bug in CGIHTTPServer.py. Internet Data handling ---------------------- - In rfc822.py, add a new class AddressList. Also support a new overridable method, isheader(). Also add a get() method similar to dictionaries (and make getheader() an alias for it). Also, be smarter about seekable (test whether fp.tell() works) and test for presence of unread() method before trying seeks. - In sgmllib.py, restore the call to report_unbalanced() that was lost long ago. Also some other improvements: handle , allow . and - in entity names, and allow \r\n as line separator. - Some restructuring and generalization done to multifile.py; support a 'seekable' flag. Restricted Execution -------------------- - Improvements to rexec.py: package support; support a (minimal) sys.exc_info(). Also made the (test) main program a bit fancier (you can now use it to run arbitrary Python scripts in restricted mode). Tkinter ------- - On Unix, Tkinter can now safely be used from a multi-threaded application. (Formerly, no threads would make progress while Tkinter's mainloop() was active, because it didn't release the Python interpreter lock.) Unfortunately, on Windows, threads other than the main thread should not call update() or update_idletasks() because this will deadlock the application. - An interactive interpreter that uses readline and Tkinter no longer uses up all available CPU time. - Even if readline is not used, Tk windows created in an interactive interpreter now get continuously updated. (This even works in Windows as long as you don't hit a key.) - New demos in Demo/tkinter/guido/: brownian.py, redemo.py, switch.py. - No longer register Tcl_finalize() as a low-level exit handler. It may call back into Python, and that's a bad idea. - Allow binding of Tcl commands (given as a string). - Some minor speedups; replace explicitly coded getint() with int() in most places. - In FileDialog.py, remember the directory of the selected file, if given. - Change the names of all methods in the Wm class: they are now wm_title(), etc. The old names (title() etc.) are still defined as aliases. - Add a new method of interpreter objects, interpaddr(). This returns the address of the Tcl interpreter object, as an integer. Not very useful for the Python programmer, but this can be called by another C extension that needs to make calls into the Tcl/Tk C API and needs to get the address of the Tcl interpreter object. A simple cast of the return value to (Tcl_Interp *) will do the trick. Windows General --------------- - Don't insist on proper case for module source files if the filename is all uppercase (e.g. FOO.PY now matches foo; but FOO.py still doesn't). This should address problems with this feature on oldfashioned filesystems (Novell servers?). Windows Library --------------- - os.environ is now all uppercase, but accesses are case insensitive, and the putenv() calls made as a side effect of changing os.environ are case preserving. - Removed samefile(), sameopenfile(), samestat() from os.path (aka ntpath.py) -- these cannot be made to work reliably (at least I wouldn't know how). - Fixed os.pipe() so that it returns file descriptors acceptable to os.read() and os.write() (like it does on Unix), rather than Windows file handles. - Added a table of WSA error codes to socket.py. - In the select module, put the (huge) file descriptor arrays on the heap. - The getpass module now raises KeyboardInterrupt when it sees ^C. - In mailbox.py, fix tell/seek when using files opened in text mode. - In rfc822.py, fix tell/seek when using files opened in text mode. - In the msvcrt extension module, release the interpreter lock for calls that may block: _locking(), _getch(), _getche(). Also fix a bogus error return when open_osfhandle() doesn't have the right argument list. Windows Installer ----------------- - The registry key used is now "1.5" instead of "1.5.x" -- so future versions of 1.5 and Mark Hammond's win32all installer don't need to be resynchronized. Windows Tools ------------- - Several improvements to freeze specifically for Windows. Windows Build Procedure ----------------------- - The VC++ project files and the WISE installer have been moved to the PCbuild subdirectory, so they are distributed in the same subdirectory where they must be used. This avoids confusion. - New project files for Windows 3.1 port by Jim Ahlstrom. - Got rid of the obsolete subdirectory PC/setup_nt/. - The projects now use distinct filenames for the .exe, .dll, .lib and .pyd files built in debug mode (by appending "_d" to the base name, before the extension). This makes it easier to switch between the two and get the right versions. There's a pragma in config.h that directs the linker to include the appropriate .lib file (so python15.lib no longer needs to be explicit in your project). - The installer now installs more files (e.g. config.h). The idea is that you shouldn't need the source distribution if you want build your own extensions in C or C++. Tools and Demos --------------- - New script nm2def.py by Marc-Andre Lemburg, to construct PC/python_nt.def automatically (some hand editing still required). - New tool ndiff.py: Tim Peters' text diffing tool. - Various and sundry improvements to the freeze script. - The script texi2html.py (which was part of the Doc tree but is no longer used there) has been moved to the Tools/scripts subdirectory. - Some generalizations in the webchecker code. There's now a primnitive gui for websucker.py: wsgui.py. (In Tools/webchecker/.) - The ftpmirror.py script now handles symbolic links properly, and also files with multiple spaces in their names. - The 1.5.1 tabnanny.py suffers an assert error if fed a script whose last line is both indented and lacks a newline. This is now fixed. Python/C API ------------ - Added missing prototypes for PyEval_CallFunction() and PyEval_CallMethod(). - New macro PyList_SET_ITEM(). - New macros to access object members for PyFunction, PyCFunction objects. - New APIs PyImport_AppendInittab() an PyImport_ExtendInittab() to dynamically add one or many entries to the table of built-in modules. - New macro Py_InitModule3(name, methods, doc) which calls Py_InitModule4() with appropriate arguments. (The -4 variant requires you to pass an obscure version number constant which is always the same.) - New APIs PySys_WriteStdout() and PySys_WriteStderr() to write to sys.stdout or sys.stderr using a printf-like interface. (Used in _tkinter.c, for example.) - New APIs for conversion between Python longs and C 'long long' if your compiler supports it. - PySequence_In() is now called PySequence_Contains(). (PySequence_In() is still supported for b/w compatibility; it is declared obsolete because its argument order is confusing.) - PyDict_GetItem() and PyDict_GetItemString() are changed so that they *never* raise an exception -- (even if the hash() fails, simply clear the error). This was necessary because there is lots of code out there that already assumes this. - Changes to PySequence_Tuple() and PySequence_List() to use the length of a sequence only as a hint -- if an IndexError happens earlier, take that. (Formerly, this was considered an error.) - Reformatted abstract.c to give it a more familiar "look" and fixed many error checking bugs. - Add NULL pointer checks to all calls of a C function through a type object and extensions (e.g. nb_add). - The code that initializes sys.path now calls Py_GetPythonHome() instead of getenv("PYTHONHOME"). This, together with the new API Py_SetPythonHome(), makes it easier for embedding applications to change the notion of Python's "home" directory (where the libraries etc. are sought). - Fixed a very old bug in the parsing of "O?" format specifiers. ====================================================================== ======================================== ==> Release 1.5.1 (October 31, 1998) <== ======================================== From 1.5 to 1.5.1 ================= General ------- - The documentation is now unbundled. It has also been extensively modified (mostly to implement a new and more uniform formatting style). We figure that most people will prefer to download one of the preformatted documentation sets (HTML, PostScript or PDF) and that only a minority have a need for the LaTeX or FrameMaker sources. Of course, the unbundled documentation sources still released -- just not in the same archive file, and perhaps not on the same date. - All bugs noted on the errors page (and many unnoted) are fixed. All new bugs take their places. - No longer a core dump when attempting to print (or repr(), or str()) a list or dictionary that contains an instance of itself; instead, the recursive entry is printed as [...] or {...}. See Py_ReprEnter() and Py_ReprLeave() below. Comparisons of such objects still go beserk, since this requires a different kind of fix; fortunately, this is a less common scenario in practice. Syntax change ------------- - The raise statement can now be used without arguments, to re-raise a previously set exception. This should be used after catching an exception with an except clause only, either in the except clause or later in the same function. Import and module handling -------------------------- - The implementation of import has changed to use a mutex (when threading is supported). This means that when two threads simultaneously import the same module, the import statements are serialized. Recursive imports are not affected. - Rewrote the finalization code almost completely, to be much more careful with the order in which modules are destroyed. Destructors will now generally be able to reference built-in names such as None without trouble. - Case-insensitive platforms such as Mac and Windows require the case of a module's filename to match the case of the module name as specified in the import statement (see below). - The code for figuring out the default path now distinguishes between files, modules, executable files, and directories. When expecting a module, we also look for the .pyc or .pyo file. Parser/tokenizer changes ------------------------ - The tokenizer can now warn you when your source code mixes tabs and spaces for indentation in a manner that depends on how much a tab is worth in spaces. Use "python -t" or "python -v" to enable this option. Use "python -tt" to turn the warnings into errors. (See also tabnanny.py and tabpolice.py below.) - Return unsigned characters from tok_nextc(), so '\377' isn't mistaken for an EOF character. - Fixed two pernicious bugs in the tokenizer that only affected AIX. One was actually a general bug that was triggered by AIX's smaller I/O buffer size. The other was a bug in the AIX optimizer's loop unrolling code; swapping two statements made the problem go away. Tools, demos and miscellaneous files ------------------------------------ - There's a new version of Misc/python-mode.el (the Emacs mode for Python) which is much smarter about guessing the indentation style used in a particular file. Lots of other cool features too! - There are two new tools in Tools/scripts: tabnanny.py and tabpolice.py, implementing two different ways of checking whether a file uses indentation in a way that is sensitive to the interpretation of a tab. The preferred module is tabnanny.py (by Tim Peters). - Some new demo programs: Demo/tkinter/guido/paint.py -- Dave Mitchell Demo/sockets/unixserver.py -- Piet van Oostrum - Much better freeze support. The freeze script can now freeze hierarchical module names (with a corresponding change to import.c), and has a few extra options (e.g. to suppress freezing specific modules). It also does much more on Windows NT. - Version 1.0 of the faq wizard is included (only very small changes since version 0.9.0). - New feature for the ftpmirror script: when removing local files (i.e., only when -r is used), do a recursive delete. Configuring and building Python ------------------------------- - Get rid of the check for -linet -- recent Sequent Dynix systems don't need this any more and apparently it screws up their configuration. - Some changes because gcc on SGI doesn't support '-all'. - Changed the build rules to use $(LIBRARY) instead of -L.. -lpython$(VERSION) since the latter trips up the SunOS 4.1.x linker (sigh). - Fix the bug where the '# dgux is broken' comment in the Makefile tripped over Make on some platforms. - Changes for AIX: install the python.exp file; properly use $(srcdir); the makexp_aix script now removes C++ entries of the form Class::method. - Deleted some Makefile targets only used by the (long obsolete) gMakefile hacks. Extension modules ----------------- - Performance and threading improvements to the socket and bsddb modules, by Christopher Lindblad of Infoseek. - Added operator.__not__ and operator.not_. - In the thread module, when a thread exits due to an unhandled exception, don't store the exception information in sys.last_*; it prevents proper calling of destructors of local variables. - Fixed a number of small bugs in the cPickle module. - Changed find() and rfind() in the strop module so that find("x","",2) returns -1, matching the implementation in string.py. - In the time module, be more careful with the result of ctime(), and test for HAVE_MKTIME before usinmg mktime(). - Doc strings contributed by Mitch Chapman to the termios, pwd, gdbm modules. - Added the LOG_SYSLOG constant to the syslog module, if defined. Standard library modules ------------------------ - All standard library modules have been converted to an indentation style using either only tabs or only spaces -- never a mixture -- if they weren't already consistent according to tabnanny. This means that the new -t option (see above) won't complain about standard library modules. - New standard library modules: threading -- GvR and the thread-sig Java style thread objects -- USE THIS!!! getpass -- Piers Lauder simple utilities to prompt for a password and to retrieve the current username imaplib -- Piers Lauder interface for the IMAP4 protocol poplib -- David Ascher, Piers Lauder interface for the POP3 protocol smtplib -- Dragon De Monsyne interface for the SMTP protocol - Some obsolete modules moved to a separate directory (Lib/lib-old) which is *not* in the default module search path: Para addpack codehack fmt lockfile newdir ni rand tb - New version of the PCRE code (Perl Compatible Regular Expressions -- the re module and the supporting pcre extension) by Andrew Kuchling. Incompatible new feature in re.sub(): the handling of escapes in the replacement string has changed. - Interface change in the copy module: a __deepcopy__ method is now called with the memo dictionary as an argument. - Feature change in the tokenize module: differentiate between NEWLINE token (an official newline) and NL token (a newline that the grammar ignores). - Several bugfixes to the urllib module. It is now truly thread-safe, and several bugs and a portability problem have been fixed. New features, all due to Sjoerd Mullender: When creating a temporary file, it gives it an appropriate suffix. Support the "data:" URL scheme. The open() method uses the tempcache. - New version of the xmllib module (this time with a test suite!) by Sjoerd Mullender. - Added debugging code to the telnetlib module, to be able to trace the actual traffic. - In the rfc822 module, added support for deleting a header (still no support for adding headers, though). Also fixed a bug where an illegal address would cause a crash in getrouteaddr(), fixed a sign reversal in mktime_tz(), and use the local timezone by default (the latter two due to Bill van Melle). - The normpath() function in the dospath and ntpath modules no longer does case normalization -- for that, use the separate function normcase() (which always existed); normcase() has been sped up and fixed (it was the cause of a crash in Mark Hammond's installer in certain locales). - New command supported by the ftplib module: rmd(); also fixed some minor bugs. - The profile module now uses a different timer function by default -- time.clock() is generally better than os.times(). This makes it work better on Windows NT, too. - The tempfile module now recovers when os.getcwd() raises an exception. - Fixed some bugs in the random module; gauss() was subtly wrong, and vonmisesvariate() should return a full circle. Courtesy Mike Miller, Lambert Meertens (gauss()), and Magnus Kessler (vonmisesvariate()). - Better default seed in the whrandom module, courtesy Andrew Kuchling. - Fix slow close() in shelve module. - The Unix mailbox class in the mailbox module is now more robust when a line begins with the string "From " but is definitely not the start of a new message. The pattern used can be changed by overriding a method or class variable. - Added a rmtree() function to the copy module. - Fixed several typos in the pickle module. Also fixed problems when unpickling in restricted execution environments. - Added docstrings and fixed a typo in the py_compile and compileall modules. At Mark Hammond's repeated request, py_compile now append a newline to the source if it needs one. Both modules support an extra parameter to specify the purported source filename (to be used in error messages). - Some performance tweaks by Jeremy Hylton to the gzip module. - Fixed a bug in the merge order of dictionaries in the ConfigParser module. Courtesy Barry Warsaw. - In the multifile module, support the optional second parameter to seek() when possible. - Several fixes to the gopherlib module by Lars Marius Garshol. Also, urlparse now correctly handles Gopher URLs with query strings. - Fixed a tiny bug in format_exception() in the traceback module. Also rewrite tb_lineno() to be compatible with JPython (and not disturb the current exception!); by Jim Hugunin. - The httplib module is more robust when servers send a short response -- courtesy Tim O'Malley. Tkinter and friends ------------------- - Various typos and bugs fixed. - New module Tkdnd implements a drag-and-drop protocol (within one application only). - The event_*() widget methods have been restructured slightly -- they no longer use the default root. - The interfaces for the bind*() and unbind() widget methods have been redesigned; the bind*() methods now return the name of the Tcl command created for the callback, and this can be passed as a optional argument to unbind() in order to delete the command (normally, such commands are automatically unbound when the widget is destroyed, but for some applications this isn't enough). - Variable objects now have trace methods to interface to Tcl's variable tracing facilities. - Image objects now have an optional keyword argument, 'master', to specify a widget (tree) to which they belong. The image_names() and image_types() calls are now also widget methods. - There's a new global call, Tkinter.NoDefaultRoot(), which disables all use of the default root by the Tkinter library. This is useful to debug applications that are in the process of being converted from relying on the default root to explicit specification of the root widget. - The 'exit' command is deleted from the Tcl interpreter, since it provided a loophole by which one could (accidentally) exit the Python interpreter without invoking any cleanup code. - Tcl_Finalize() is now registered as a Python low-level exit handle, so Tcl will be finalized when Python exits. The Python/C API ---------------- - New function PyThreadState_GetDict() returns a per-thread dictionary intended for storing thread-local global variables. - New functions Py_ReprEnter() and Py_ReprLeave() use the per-thread dictionary to allow recursive container types to detect recursion in their repr(), str() and print implementations. - New function PyObject_Not(x) calculates (not x) according to Python's standard rules (basically, it negates the outcome PyObject_IsTrue(x). - New function _PyModule_Clear(), which clears a module's dictionary carefully without removing the __builtins__ entry. This is implied when a module object is deallocated (this used to clear the dictionary completely). - New function PyImport_ExecCodeModuleEx(), which extends PyImport_ExecCodeModule() by adding an extra parameter to pass it the true file. - New functions Py_GetPythonHome() and Py_SetPythonHome(), intended to allow embedded applications to force a different value for PYTHONHOME. - New global flag Py_FrozenFlag is set when this is a "frozen" Python binary; it suppresses warnings about not being able to find the standard library directories. - New global flag Py_TabcheckFlag is incremented by the -t option and causes the tokenizer to issue warnings or errors about inconsistent mixing of tabs and spaces for indentation. Miscellaneous minor changes and bug fixes ----------------------------------------- - Improved the error message when an attribute of an attribute-less object is requested -- include the name of the attribute and the type of the object in the message. - Sped up int(), long(), float() a bit. - Fixed a bug in list.sort() that would occasionally dump core. - Fixed a bug in PyNumber_Power() that caused numeric arrays to fail when taken tothe real power. - Fixed a number of bugs in the file reading code, at least one of which could cause a core dump on NT, and one of which would occasionally cause file.read() to return less than the full contents of the file. - Performance hack by Vladimir Marangozov for stack frame creation. - Make sure setvbuf() isn't used unless HAVE_SETVBUF is defined. Windows 95/NT ------------- - The .lib files are now part of the distribution; they are collected in the subdirectory "libs" of the installation directory. - The extension modules (.pyd files) are now collected in a separate subdirectory of the installation directory named "DLLs". - The case of a module's filename must now match the case of the module name as specified in the import statement. This is an experimental feature -- if it turns out to break in too many situations, it will be removed (or disabled by default) in the future. It can be disabled on a per-case basis by setting the environment variable PYTHONCASEOK (to any value). ====================================================================== ===================================== ==> Release 1.5 (January 3, 1998) <== ===================================== From 1.5b2 to 1.5 ================= - Newly documentated module: BaseHTTPServer.py, thanks to Greg Stein. - Added doc strings to string.py, stropmodule.c, structmodule.c, thanks to Charles Waldman. - Many nits fixed in the manuals, thanks to Fred Drake and many others (especially Rob Hooft and Andrew Kuchling). The HTML version now uses HTML markup instead of inline GIF images for tables; only two images are left (for obsure bits of math). The index of the HTML version has also been much improved. Finally, it is once again possible to generate an Emacs info file from the library manual (but I don't commit to supporting this in future versions). - New module: telnetlib.py (a simple telnet client library). - New tool: Tools/versioncheck/, by Jack Jansen. - Ported zlibmodule.c and bsddbmodule.c to NT; The project file for MS DevStudio 5.0 now includes new subprojects to build the zlib and bsddb extension modules. - Many small changes again to Tkinter.py -- mostly bugfixes and adding missing routines. Thanks to Greg McFarlane for reporting a bunch of problems and proofreading my fixes. - The re module and its documentation are up to date with the latest version released to the string-sig (Dec. 22). - Stop test_grp.py from failing when the /etc/group file is empty (yes, this happens!). - Fix bug in integer conversion (mystrtoul.c) that caused 4294967296==0 to be true! - The VC++ 4.2 project file should be complete again. - In tempfile.py, use a better template on NT, and add a new optional argument "suffix" with default "" to specify a specific extension for the temporary filename (needed sometimes on NT but perhaps also handy elsewhere). - Fixed some bugs in the FAQ wizard, and converted it to use re instead of regex. - Fixed a mysteriously undetected error in dlmodule.c (it was using a totally bogus routine name to raise an exception). - Fixed bug in import.c which wasn't using the new "dos-8x3" name yet. - Hopefully harmless changes to the build process to support shared libraries on DG/UX. This adds a target to create libpython$(VERSION).so; however this target is *only* for DG/UX. - Fixed a bug in the new format string error checking in getargs.c. - A simple fix for infinite recursion when printing __builtins__: reset '_' to None before printing and set it to the printed variable *after* printing (and only when printing is successful). - Fixed lib-tk/SimpleDialog.py to keep the dialog visible even if the parent window is not (Skip Montanaro). - Fixed the two most annoying problems with ftp URLs in urllib.urlopen(); an empty file now correctly raises an error, and it is no longer required to explicitly close the returned "file" object before opening another ftp URL to the same host and directory. ====================================================================== From 1.5b1 to 1.5b2 =================== - Fixed a bug in cPickle.c that caused it to crash right away because the version string had a different format. - Changes in pickle.py and cPickle.c: when unpickling an instance of a class that doesn't define the __getinitargs__() method, the __init__() constructor is no longer called. This makes a much larger group of classes picklable by default, but may occasionally change semantics. To force calling __init__() on unpickling, define a __getinitargs__() method. Other changes too, in particular cPickle now handles classes defined in packages correctly. The same change applies to copying instances with copy.py. The cPickle.c changes and some pickle.py changes are courtesy Jim Fulton. - Locale support in he "re" (Perl regular expressions) module. Use the flag re.L (or re.LOCALE) to enable locale-specific matching rules for \w and \b. The in-line syntax for this flag is (?L). - The built-in function isinstance(x, y) now also succeeds when y is a type object and type(x) is y. - repr() and str() of class and instance objects now reflect the package/module in which the class is defined. - Module "ni" has been removed. (If you really need it, it's been renamed to "ni1". Let me know if this causes any problems for you. Package authors are encouraged to write __init__.py files that support both ni and 1.5 package support, so the same version can be used with Python 1.4 as well as 1.5.) - The thread module is now automatically included when threads are configured. (You must remove it from your existing Setup file, since it is now in its own Setup.thread file.) - New command line option "-x" to skip the first line of the script; handy to make executable scripts on non-Unix platforms. - In importdl.c, add the RTLD_GLOBAL to the dlopen() flags. I haven't checked how this affects things, but it should make symbols in one shared library available to the next one. - The Windows installer now installs in the "Program Files" folder on the proper volume by default. - The Windows configuration adds a new main program, "pythonw", and registers a new extension, ".pyw" that invokes this. This is a pstandard Python interpreter that does not pop up a console window; handy for pure Tkinter applications. All output to the original stdout and stderr is lost; reading from the original stdin yields EOF. Also, both python.exe and pythonw.exe now have a pretty icon (a green snake in a box, courtesy Mark Hammond). - Lots of improvements to emacs-mode.el again. See Barry's web page: http://www.python.org/ftp/emacs/pmdetails.html. - Lots of improvements and additions to the library reference manual; many by Fred Drake. - Doc strings for the following modules: rfc822.py, posixpath.py, ntpath.py, httplib.py. Thanks to Mitch Chapman and Charles Waldman. - Some more regression testing. - An optional 4th (maxsplit) argument to strop.replace(). - Fixed handling of maxsplit in string.splitfields(). - Tweaked os.environ so it can be pickled and copied. - The portability problems caused by indented preprocessor commands and C++ style comments should be gone now. - In random.py, added Pareto and Weibull distributions. - The crypt module is now disabled in Modules/Setup.in by default; it is rarely needed and causes errors on some systems where users often don't know how to deal with those. - Some improvements to the _tkinter build line suggested by Case Roole. - A full suite of platform specific files for NetBSD 1.x, submitted by Anders Andersen. - New Solaris specific header STROPTS.py. - Moved a confusing occurrence of *shared* from the comments in Modules/Setup.in (people would enable this one instead of the real one, and get disappointing results). - Changed the default mode for directories to be group-writable when the installation process creates them. - Check for pthread support in "-l_r" for FreeBSD/NetBSD, and support shared libraries for both. - Support FreeBSD and NetBSD in posixfile.py. - Support for the "event" command, new in Tk 4.2. By Case Roole. - Add Tix_SafeInit() support to tkappinit.c. - Various bugs fixed in "re.py" and "pcre.c". - Fixed a bug (broken use of the syntax table) in the old "regexpr.c". - In frozenmain.c, stdin is made unbuffered too when PYTHONUNBUFFERED is set. - Provide default blocksize for retrbinary in ftplib.py (Skip Montanaro). - In NT, pick the username up from different places in user.py (Jeff Bauer). - Patch to urlparse.urljoin() for ".." and "..#1", Marc Lemburg. - Many small improvements to Jeff Rush' OS/2 support. - ospath.py is gone; it's been obsolete for so many years now... - The reference manual is now set up to prepare better HTML (still using webmaker, alas). - Add special handling to /Tools/freeze for Python modules that are imported implicitly by the Python runtime: 'site' and 'exceptions'. - Tools/faqwiz 0.8.3 -- add an option to suppress URL processing inside
, by "Scott".

- Added ConfigParser.py, a generic parser for sectioned configuration
files.

- In _localemodule.c, LC_MESSAGES is not always defined; put it
between #ifdefs.

- Typo in resource.c: RUSAGE_CHILDERN -> RUSAGE_CHILDREN.

- Demo/scripts/newslist.py: Fix the way the version number is gotten
out of the RCS revision.

- PyArg_Parse[Tuple] now explicitly check for bad characters at the
end of the format string.

- Revamped PC/example_nt to support VC++ 5.x.

- .sort() now uses a modified quicksort by Raymund Galvin,
after studying the GNU libg++ quicksort.  This should be much faster
if there are lots of duplicates, and otherwise at least as good.

- Added "uue" as an alias for "uuencode" to mimetools.py.  (Hm, the
uudecode bug where it complaints about trailing garbage is still there 
:-( ).

- pickle.py requires integers in text mode to be in decimal notation
(it used to accept octal and hex, even though it would only generate
decimal numbers).

- In string.atof(), don't fail when the "re" module is unavailable.
Plug the ensueing security leak by supplying an empty __builtins__
directory to eval().

- A bunch of small fixes and improvements to Tkinter.py.

- Fixed a buffer overrun in PC/getpathp.c.


======================================================================


From 1.5a4 to 1.5b1
===================

- The Windows NT/95 installer now includes full HTML of all manuals.
It also has a checkbox that lets you decide whether to install the
interpreter and library.  The WISE installer script for the installer
is included in the source tree as PC/python15.wse, and so are the
icons used for Python files.  The config.c file for the Windows build
is now complete with the pcre module.

- sys.ps1 and sys.ps2 can now arbitrary objects; their str() is
evaluated for the prompt.

- The reference manual is brought up to date (more or less -- it still
needs work, e.g. in the area of package import).

- The icons used by latex2html are now included in the Doc
subdirectory (mostly so that tarring up the HTML files can be fully
automated).  A simple index.html is also added to Doc (it only works
after you have successfully run latex2html).

- For all you would-be proselytizers out there: a new version of
Misc/BLURB describes Python more concisely, and Misc/comparisons
compares Python to several other languages.  Misc/BLURB.WINDOWS
contains a blurb specifically aimed at Windows programmers (by Mark
Hammond).

- A new version of the Python mode for Emacs is included as
Misc/python-mode.el.  There are too many new features to list here.
See http://www.python.org/ftp/emacs/pmdetails.html for more info.

- New module fileinput makes iterating over the lines of a list of
files easier.  (This still needs some more thinking to make it more
extensible.)

- There's full OS/2 support, courtesy Jeff Rush.  To build the OS/2
version, see PC/readme.txt and PC/os2vacpp.  This is for IBM's Visual
Age C++ compiler.  I expect that Jeff will also provide a binary
release for this platform.

- On Linux, the configure script now uses '-Xlinker -export-dynamic'
instead of '-rdynamic' to link the main program so that it exports its
symbols to shared libraries it loads dynamically.  I hope this doesn't
break on older Linux versions; it is needed for mklinux and appears to
work on Linux 2.0.30.

- Some Tkinter resstructuring: the geometry methods that apply to a
master are now properly usable on toplevel master widgets.  There's a
new (internal) widget class, BaseWidget.  New, longer "official" names
for the geometry manager methods have been added,
e.g. "grid_columnconfigure()" instead of "columnconfigure()".  The old
shorter names still work, and where there's ambiguity, pack wins over
place wins over grid.  Also, the bind_class method now returns its
value.

- New, RFC-822 conformant parsing of email addresses and address lists
in the rfc822 module, courtesy Ben Escoto.

- New, revamped tkappinit.c with support for popular packages (PIL,
TIX, BLT, TOGL).  For the last three, you need to execute the Tcl
command "load {} Tix" (or Blt, or Togl) to gain access to them.
The Modules/Setup line for the _tkinter module has been rewritten
using the cool line-breaking feature of most Bourne shells.

- New socket method connect_ex() returns the error code from connect()
instead of raising an exception on errors; this makes the logic
required for asynchronous connects simpler and more efficient.

- New "locale" module with (still experimental) interface to the
standard C library locale interface, courtesy Martin von Loewis.  This
does not repeat my mistake in 1.5a4 of always calling
setlocale(LC_ALL, "").  In fact, we've pretty much decided that
Python's standard numerical formatting operations should always use
the conventions for the C locale; the locale module contains utility
functions to format numbers according to the user specified locale.
(All this is accomplished by an explicit call to setlocale(LC_NUMERIC,
"C") after locale-changing calls.)  See the library manual. (Alas, the
promised changes to the "re" module for locale support have not been
materialized yet.  If you care, volunteer!)

- Memory leak plugged in Py_BuildValue when building a dictionary.

- Shared modules can now live inside packages (hierarchical module
namespaces).  No changes to the shared module itself are needed.

- Improved policy for __builtins__: this is a module in __main__ and a
dictionary everywhere else.

- Python no longer catches SIGHUP and SIGTERM by default.  This was
impossible to get right in the light of thread contexts.  If you want
your program to clean up when a signal happens, use the signal module
to set up your own signal handler.

- New Python/C API PyNumber_CoerceEx() does not return an exception
when no coercion is possible.  This is used to fix a problem where
comparing incompatible numbers for equality would raise an exception
rather than return false as in Python 1.4 -- it once again will return
false.

- The errno module is changed again -- the table of error messages
(errorstr) is removed.  Instead, you can use os.strerror().  This
removes redundance and a potential locale dependency.

- New module xmllib, to parse XML files.  By Sjoerd Mullender.

- New C API PyOS_AfterFork() is called after fork() in posixmodule.c.
It resets the signal module's notion of what the current process ID
and thread are, so that signal handlers will work after (and across)
calls to os.fork().

- Fixed most occurrences of fatal errors due to missing thread state.

- For vgrind (a flexible source pretty printer) fans, there's a simple
Python definition in Misc/vgrindefs, courtesy Neale Pickett.

- Fixed memory leak in exec statement.

- The test.pystone module has a new function, pystones(loops=LOOPS),
which returns a (benchtime, stones) tuple.  The main() function now
calls this and prints the report.

- Package directories now *require* the presence of an __init__.py (or
__init__.pyc) file before they are considered as packages.  This is
done to prevent accidental subdirectories with common names from
overriding modules with the same name.

- Fixed some strange exceptions in __del__ methods in library modules
(e.g. urllib).  This happens because the builtin names are already
deleted by the time __del__ is called.  The solution (a hack, but it
works) is to set some instance variables to 0 instead of None.

- The table of built-in module initializers is replaced by a pointer
variable.  This makes it possible to switch to a different table at
run time, e.g. when a collection of modules is loaded from a shared
library.  (No example code of how to do this is given, but it is
possible.)  The table is still there of course, its name prefixed with
an underscore and used to initialize the pointer.

- The warning about a thread still having a frame now only happens in
verbose mode.

- Change the signal finialization so that it also resets the signal
handlers.  After this has been called, our signal handlers are no
longer active!

- New version of tokenize.py (by Ka-Ping Yee) recognizes raw string
literals.  There's now also a test fort this module.

- The copy module now also uses __dict__.update(state) instead of
going through individual attribute assignments, for class instances
without a __setstate__ method.

- New module reconvert translates old-style (regex module) regular
expressions to new-style (re module, Perl-style) regular expressions.

- Most modules that used to use the regex module now use the re
module.  The grep module has a new pgrep() function which uses
Perl-style regular expressions.

- The (very old, backwards compatibility) regexp.py module has been
deleted.

- Restricted execution (rexec): added the pcre module (support for the
re module) to the list of trusted extension modules.

- New version of Jim Fulton's CObject object type, adds
PyCObject_FromVoidPtrAndDesc() and PyCObject_GetDesc() APIs.

- Some patches to Lee Busby's fpectl mods that accidentally didn't
make it into 1.5a4.

- In the string module, add an optional 4th argument to count(),
matching find() etc.

- Patch for the nntplib module by Charles Waldman to add optional user
and password arguments to NNTP.__init__(), for nntp servers that need
them.

- The str() function for class objects now returns
"modulename.classname" instead of returning the same as repr().

- The parsing of \xXX escapes no longer relies on sscanf().

- The "sharedmodules" subdirectory of the installation is renamed to
"lib-dynload".  (You may have to edit your Modules/Setup file to fix
this in an existing installation!)

- Fixed Don Beaudry's mess-up with the OPT test in the configure
script.  Certain SGI platforms will still issue a warning for each
compile; there's not much I can do about this since the compiler's
exit status doesn't indicate that I was using an obsolete option.

- Fixed Barry's mess-up with {}.get(), and added test cases for it.

- Shared libraries didn't quite work under AIX because of the change
in status of the GNU readline interface.  Fix due to by Vladimir
Marangozov.


======================================================================


From 1.5a3 to 1.5a4
===================

- faqwiz.py: version 0.8; Recognize https:// as URL; ...
feature; better install instructions; removed faqmain.py (which was an
older version).

- nntplib.py: Fixed some bugs reported by Lars Wirzenius (to Debian)
about the treatment of lines starting with '.'.  Added a minimal test
function.

- struct module: ignore most whitespace in format strings.

- urllib.py: close the socket and temp file in URLopener.retrieve() so
that multiple retrievals using the same connection work.

- All standard exceptions are now classes by default; use -X to make
them strings (for backward compatibility only).

- There's a new standard exception hierarchy, defined in the standard
library module exceptions.py (which you never need to import
explicitly).  See
http://grail.cnri.reston.va.us/python/essays/stdexceptions.html for
more info.

- Three new C API functions:

  - int PyErr_GivenExceptionMatches(obj1, obj2)

    Returns 1 if obj1 and obj2 are the same object, or if obj1 is an
    instance of type obj2, or of a class derived from obj2

  - int PyErr_ExceptionMatches(obj)

    Higher level wrapper around PyErr_GivenExceptionMatches() which uses
    PyErr_Occurred() as obj1.  This will be the more commonly called
    function.

  - void PyErr_NormalizeException(typeptr, valptr, tbptr)

    Normalizes exceptions, and places the normalized values in the
    arguments.  If type is not a class, this does nothing.  If type is a
    class, then it makes sure that value is an instance of the class by:

    1. if instance is of the type, or a class derived from type, it does
       nothing.

    2. otherwise it instantiates the class, using the value as an
       argument.  If value is None, it uses an empty arg tuple, and if
       the value is a tuple, it uses just that.

- Another new C API function: PyErr_NewException() creates a new
exception class derived from Exception; when -X is given, it creates a
new string exception.

- core interpreter: remove the distinction between tuple and list
unpacking; allow an arbitrary sequence on the right hand side of any
unpack instruction.  (UNPACK_LIST and UNPACK_TUPLE now do the same
thing, which should really be called UNPACK_SEQUENCE.)

- classes: Allow assignments to an instance's __dict__ or __class__,
so you can change ivars (including shared ivars -- shock horror) and
change classes dynamically.  Also make the check on read-only
attributes of classes less draconic -- only the specials names
__dict__, __bases__, __name__ and __{get,set,del}attr__ can't be
assigned.

- Two new built-in functions: issubclass() and isinstance().  Both
take classes as their second arguments.  The former takes a class as
the first argument and returns true iff first is second, or is a
subclass of second.  The latter takes any object as the first argument
and returns true iff first is an instance of the second, or any
subclass of second.

- configure: Added configuration tests for presence of alarm(),
pause(), and getpwent().

- Doc/Makefile: changed latex2html targets.

- classes: Reverse the search order for the Don Beaudry hook so that
the first class with an applicable hook wins.  Makes more sense.

- Changed the checks made in Py_Initialize() and Py_Finalize().  It is
now legal to call these more than once.  The first call to
Py_Initialize() initializes, the first call to Py_Finalize()
finalizes.  There's also a new API, Py_IsInitalized() which checks
whether we are already initialized (in case you want to leave things
as they were).

- Completely disable the declarations for malloc(), realloc() and
free().  Any 90's C compiler has these in header files, and the tests
to decide whether to suppress the declarations kept failing on some
platforms.

- *Before* (instead of after) signalmodule.o is added, remove both
intrcheck.o and sigcheck.o.  This should get rid of warnings in ar or
ld on various systems.

- Added reop to PC/config.c

- configure: Decided to use -Aa -D_HPUX_SOURCE on HP-UX platforms.
Removed outdated HP-UX comments from README.  Added Cray T3E comments.

- Various renames of statically defined functions that had name
conflicts on some systems, e.g. strndup (GNU libc), join (Cray),
roundup (sys/types.h).

- urllib.py: Interpret three slashes in file: URL as local file (for
Netscape on Windows/Mac).

- copy.py: Make sure the objects returned by __getinitargs__() are
kept alive (in the memo) to avoid a certain kind of nasty crash.  (Not
easily reproducable because it requires a later call to
__getinitargs__() to return a tuple that happens to be allocated at
the same address.)

- Added definition of AR to toplevel Makefile.  Renamed @buildno temp
file to buildno1.

- Moved Include/assert.h to Parser/assert.h, which seems to be the
only place where it's needed.

- Tweaked the dictionary lookup code again for some more speed
(Vladimir Marangozov).

- NT build: Changed the way python15.lib is included in the other
projects.  Per Mark Hammond's suggestion, add it to the extra libs in
Settings instead of to the project's source files.

- regrtest.py: Change default verbosity so that there are only three
levels left: -q, default and -v.  In default mode, the name of each
test is now printed.  -v is the same as the old -vv.  -q is more quiet
than the old default mode.

- Removed the old FAQ from the distribution.  You now have to get it
from the web!

- Removed the PC/make_nt.in file from the distribution; it is no
longer needed.

- Changed the build sequence so that shared modules are built last.
This fixes things for AIX and doesn't hurt elsewhere.

- Improved test for GNU MP v1 in mpzmodule.c

- fileobject.c: ftell() on Linux discards all buffered data; changed
read() code to use lseek() instead to get the same effect

- configure.in, configure, importdl.c: NeXT sharedlib fixes

- tupleobject.c: PyTuple_SetItem asserts refcnt==1

- resource.c: Different strategy regarding whether to declare
getrusage() and getpagesize() -- #ifdef doesn't work, Linux has
conflicting decls in its headers.  Choice: only declare the return
type, not the argument prototype, and not on Linux.

- importdl.c, configure*: set sharedlib extensions properly for NeXT

- configure*, Makefile.in, Modules/Makefile.pre.in: AIX shared libraries
fixed; moved addition of PURIFY to LINKCC to configure

- reopmodule.c, regexmodule.c, regexpr.c, zlibmodule.c: needed casts
added to shup up various compilers.

- _tkinter.c: removed buggy mac #ifndef

- Doc: various Mac documentation changes, added docs for 'ic' module

- PC/make_nt.in: deleted

- test_time.py, test_strftime.py: tweaks to catch %Z (which may return
"")

- test_rotor.py: print b -> print `b`

- Tkinter.py: (tagOrId) -> (tagOrId,)

- Tkinter.py: the Tk class now also has a configure() method and
friends (they have been moved to the Misc class to accomplish this).

- dict.get(key[, default]) returns dict[key] if it exists, or default
if it doesn't.  The default defaults to None.  This is quicker for
some applications than using either has_key() or try:...except
KeyError:....

- Tools/webchecker/: some small changes to webchecker.py; added
websucker.py (a simple web site mirroring script).

- Dictionary objects now have a get() method (also in UserDict.py).
dict.get(key, default) returns dict[key] if it exists and default
otherwise; default defaults to None.

- Tools/scripts/logmerge.py: print the author, too.

- Changes to import: support for "import a.b.c" is now built in.  See
http://grail.cnri.reston.va.us/python/essays/packages.html
for more info.  Most important deviations from "ni.py": __init__.py is
executed in the package's namespace instead of as a submodule; and
there's no support for "__" or "__domain__".  Note that "ni.py" is not
changed to match this -- it is simply declared obsolete (while at the
same time, it is documented...:-( ).
Unfortunately, "ihooks.py" has not been upgraded (but see "knee.py"
for an example implementation of hierarchical module import written in
Python).

- More changes to import: the site.py module is now imported by
default when Python is initialized; use -S to disable it.  The site.py
module extends the path with several more directories: site-packages
inside the lib/python1.5/ directory, site-python in the lib/
directory, and pathnames mentioned in *.pth files found in either of
those directories.  See
http://grail.cnri.reston.va.us/python/essays/packages.html
for more info.

- Changes to standard library subdirectory names: those subdirectories
that are not packages have been renamed with a hypen in their name,
e.g. lib-tk, lib-stdwin, plat-win, plat-linux2, plat-sunos5, dos-8x3.
The test suite is now a package -- to run a test, you must now use
"import test.test_foo".

- A completely new re.py module is provided (thanks to Andrew
Kuchling, Tim Peters and Jeffrey Ollie) which uses Philip Hazel's
"pcre" re compiler and engine.  For a while, the "old" re.py (which
was new in 1.5a3!) will be kept around as re1.py.  The "old" regex
module and underlying parser and engine are still present -- while
regex is now officially obsolete, it will probably take several major
release cycles before it can be removed.

- The posix module now has a strerror() function which translates an
error code to a string.

- The emacs.py module (which was long obsolete) has been removed.

- The universal makefile Misc/Makefile.pre.in now features an
"install" target.  By default, installed shared libraries go into
$exec_prefix/lib/python$VERSION/site-packages/.

- The install-sh script is installed with the other configuration
specific files (in the config/ subdirectory).

- It turns out whatsound.py and sndhdr.py were identical modules.
Since there's also an imghdr.py file, I propose to make sndhdr.py the
official one.  For compatibility, whatsound.py imports * from
sndhdr.py.

- Class objects have a new attribute, __module__, giving the name of
the module in which they were declared.  This is useful for pickle and
for printing the full name of a class exception.

- Many extension modules no longer issue a fatal error when their
initialization fails; the importing code now checks whether an error
occurred during module initialization, and correctly propagates the
exception to the import statement.

- Most extension modules now raise class-based exceptions (except when
-X is used).

- Subtle changes to PyEval_{Save,Restore}Thread(): always swap the
thread state -- just don't manipulate the lock if it isn't there.

- Fixed a bug in Python/getopt.c that made it do the wrong thing when
an option was a single '-'.  Thanks to Andrew Kuchling.

- New module mimetypes.py will guess a MIME type from a filename's
extension.

- Windows: the DLL version is now settable via a resource rather than
being hardcoded.  This can be used for "branding" a binary Python
distribution.

- urllib.py is now threadsafe -- it now uses re instead of regex, and
sys.exc_info() instead of sys.exc_{type,value}.

- Many other library modules that used to use
sys.exc_{type,value,traceback} are now more thread-safe by virtue of
using sys.exc_info().

- The functions in popen2 have an optional buffer size parameter.
Also, the command argument can now be either a string (passed to the
shell) or a list of arguments (passed directly to execv).

- Alas, the thread support for _tkinter released with 1.5a3 didn't
work.  It's been rewritten.  The bad news is that it now requires a
modified version of a file in the standard Tcl distribution, which you
must compile with a -I option pointing to the standard Tcl source
tree.  For this reason, the thread support is disabled by default.

- The errno extension module adds two tables: errorcode maps errno
numbers to errno names (e.g. EINTR), and errorstr maps them to
message strings.  (The latter is redundant because the new call
posix.strerror() now does the same, but alla...)  (Marc-Andre Lemburg)

- The readline extension module now provides some interfaces to
internal readline routines that make it possible to write a completer
in Python.  An example completer, rlcompleter.py, is provided.

	When completing a simple identifier, it completes keywords,
	built-ins and globals in __main__; when completing
	NAME.NAME..., it evaluates (!) the expression up to the last
	dot and completes its attributes.

	It's very cool to do "import string" type "string.", hit the
	completion key (twice), and see the list of names defined by
	the string module!

	Tip: to use the tab key as the completion key, call

	    readline.parse_and_bind("tab: complete")

- The traceback.py module has a new function tb_lineno() by Marc-Andre
Lemburg which extracts the line number from the linenumber table in
the code object.  Apparently the traceback object doesn't contains the
right linenumber when -O is used.  Rather than guessing whether -O is
on or off, the module itself uses tb_lineno() unconditionally.

- Fixed Demo/tkinter/matt/canvas-moving-or-creating.py: change bind()
to tag_bind() so it works again.

- The pystone script is now a standard library module.  Example use:
"import test.pystone; test.pystone.main()".

- The import of the readline module in interactive mode is now also
attempted when -i is specified.  (Yes, I know, giving in to Marc-Andre
Lemburg, who asked for this. :-)

- rfc822.py: Entirely rewritten parseaddr() function by Sjoerd
Mullender, to be closer to the standard.  This fixes the getaddr()
method.  Unfortunately, getaddrlist() is as broken as ever, since it
splits on commas without regard for RFC 822 quoting conventions.

- pprint.py: correctly emit trailing "," in singleton tuples.

- _tkinter.c: export names for its type objects, TkappType and
TkttType.

- pickle.py: use __module__ when defined; fix a particularly hard to
reproduce bug that confuses the memo when temporary objects are
returned by custom pickling interfaces; and a semantic change: when
unpickling the instance variables of an instance, use
inst.__dict__.update(value) instead of a for loop with setattr() over
the value.keys().  This is more consistent (the pickling doesn't use
getattr() either but pickles inst.__dict__) and avoids problems with
instances that have a __setattr__ hook.  But it *is* a semantic change
(because the setattr hook is no longer used).  So beware!

- config.h is now installed (at last) in
$exec_prefix/include/python1.5/.  For most sites, this means that it
is actually in $prefix/include/python1.5/, with all the other Python
include files, since $prefix and $exec_prefix are the same by
default.

- The imp module now supports parts of the functionality to implement
import of hierarchical module names.  It now supports find_module()
and load_module() for all types of modules.  Docstrings have been
added for those functions in the built-in imp module that are still
relevant (some old interfaces are obsolete).  For a sample
implementation of hierarchical module import in Python, see the new
library module knee.py.

- The % operator on string objects now allows arbitrary nested parens
in a %(...)X style format.  (Brad Howes)

- Reverse the order in which Setup and Setup.local are passed to the
makesetup script.  This allows variable definitions in Setup.local to
override definitions in Setup.  (But you'll still have to edit Setup
if you want to disable modules that are enabled by default, or if such
modules need non-standard options.)

- Added PyImport_ImportModuleEx(name, globals, locals, fromlist); this
is like PyImport_ImporModule(name) but receives the globals and locals
dict and the fromlist arguments as well.  (The name is a char*; the
others are PyObject*s).

- The 'p' format in the struct extension module alloded to above is
new in 1.5a4.

- The types.py module now uses try-except in a few places to make it
more likely that it can be imported in restricted mode.  Some type
names are undefined in that case, e.g. CodeType (inaccessible),
FileType (not always accessible), and TracebackType and FrameType
(inaccessible).

- In urllib.py: added separate administration of temporary files
created y URLopener.retrieve() so cleanup() can properly remove them.
The old code removed everything in tempcache which was a bad idea if
the user had passed a non-temp file into it.  Also, in basejoin(),
interpret relative paths starting in "../".  This is necessary if the
server uses symbolic links.

- The Windows build procedure and project files are now based on
Microsoft Visual C++ 5.x.  The build now takes place in the PCbuild
directory.  It is much more robust, and properly builds separate Debug
and Release versions.  (The installer will be added shortly.)

- Added casts and changed some return types in regexpr.c to avoid
compiler warnings or errors on some platforms.

- The AIX build tools for shared libraries now supports VPATH.  (Donn
Cave)

- By default, disable the "portable" multimedia modules audioop,
imageop, and rgbimg, since they don't work on 64-bit platforms.

- Fixed a nasty bug in cStringIO.c when code was actually using the
close() method (the destructors would try to free certain fields a
second time).

- For those who think they need it, there's a "user.py" module.  This
is *not* imported by default, but can be imported to run user-specific
setup commands, ~/.pythonrc.py.

- Various speedups suggested by Fredrik Lundh, Marc-Andre Lemburg,
Vladimir Marangozov, and others.

- Added os.altsep; this is '/' on DOS/Windows, and None on systems
with a sane filename syntax.

- os.py: Write out the dynamic OS choice, to avoid exec statements.
Adding support for a new OS is now a bit more work, but I bet that
'dos' or 'nt' will cover most situations...

- The obsolete exception AccessError is now really gone.

- Tools/faqwiz/: New installation instructions show how to maintain
multiple FAQs.  Removed bootstrap script from end of faqwiz.py module.
Added instructions to bootstrap script, too.  Version bumped to 0.8.1.
Added ... feature suggested by Skip Montanaro.  Added
leading text for Roulette, default to 'Hit Reload ...'.  Fix typo in
default SRCDIR.

- Documentation for the relatively new modules "keyword" and "symbol"
has been added (to the end of the section on the parser extension
module).

- In module bisect.py, but functions have two optional argument 'lo'
and 'hi' which allow you to specify a subsequence of the array to
operate on.

- In ftplib.py, changed most methods to return their status (even when
it is always "200 OK") rather than swallowing it.

- main() now calls setlocale(LC_ALL, ""), if setlocale() and
 are defined.

- Changes to configure.in, the configure script, and both
Makefile.pre.in files, to support SGI's SGI_ABI platform selection
environment variable.


======================================================================


From 1.4 to 1.5a3
=================

Security
--------

- If you are using the setuid script C wrapper (Misc/setuid-prog.c),
please use the new version.  The old version has a huge security leak.

Miscellaneous
-------------

- Because of various (small) incompatible changes in the Python
bytecode interpreter, the magic number for .pyc files has changed
again.

- The default module search path is now much saner.  Both on Unix and
Windows, it is essentially derived from the path to the executable
(which can be overridden by setting the environment variable
$PYTHONHOME).  The value of $PYTHONPATH on Windows is now inserted in
front of the default path, like in Unix (instead of overriding the
default path).  On Windows, the directory containing the executable is
added to the end of the path.

- A new version of python-mode.el for Emacs has been included.  Also,
a new file ccpy-style.el has been added to configure Emacs cc-mode for
the preferred style in Python C sources.

- On Unix, when using sys.argv[0] to insert the script directory in
front of sys.path, expand a symbolic link.  You can now install a
program in a private directory and have a symbolic link to it in a
public bin directory, and it will put the private directory in the
module search path.  Note that the symlink is expanded in sys.path[0]
but not in sys.argv[0], so you can still tell the name by which you
were invoked.

- It is now recommended to use ``#!/usr/bin/env python'' instead of
``#!/usr/local/bin/python'' at the start of executable scripts, except
for CGI scripts.  It has been determined that the use of /usr/bin/env
is more portable than that of /usr/local/bin/python -- scripts almost
never have to be edited when the Python interpreter lives in a
non-standard place.  Note that this doesn't work for CGI scripts since
the python executable often doesn't live in the HTTP server's default
search path.

- The silly -s command line option and the corresponding
PYTHONSUPPRESS environment variable (and the Py_SuppressPrint global
flag in the Python/C API) are gone.

- Most problems on 64-bit platforms should now be fixed.  Andrew
Kuchling helped.  Some uncommon extension modules are still not
clean (image and audio ops?).

- Fixed a bug where multiple anonymous tuple arguments would be mixed up
when using the debugger or profiler (reported by Just van Rossum).
The simplest example is ``def f((a,b),(c,d)): print a,b,c,d''; this
would print the wrong value when run under the debugger or profiler.

- The hacks that the dictionary implementation used to speed up
repeated lookups of the same C string were removed; these were a
source of subtle problems and don't seem to serve much of a purpose
any longer.

- All traces of support for the long dead access statement have been
removed from the sources.

- Plugged the two-byte memory leak in the tokenizer when reading an
interactive EOF.

- There's a -O option to the interpreter that removes SET_LINENO
instructions and assert statements (see below); it uses and produces
.pyo files instead of .pyc files.  The speedup is only a few percent
in most cases.  The line numbers are still available in the .pyo file,
as a separate table (which is also available in .pyc files).  However,
the removal of the SET_LINENO instructions means that the debugger
(pdb) can't set breakpoints on lines in -O mode.  The traceback module
contains a function to extract a line number from the code object
referenced in a traceback object.  In the future it should be possible
to write external bytecode optimizers that create better optimized
.pyo files, and there should be more control over optimization;
consider the -O option a "teaser".  Without -O, the assert statement
actually generates code that first checks __debug__; if this variable
is false, the assertion is not checked.  __debug__ is a built-in
variable whose value is initialized to track the -O flag (it's true
iff -O is not specified).  With -O, no code is generated for assert
statements, nor for code of the form ``if __debug__: ''.
Sorry, no further constant folding happens.


Performance
-----------

- It's much faster (almost twice for pystone.py -- see
Tools/scripts).  See the entry on string interning below.

- Some speedup by using separate free lists for method objects (both
the C and the Python variety) and for floating point numbers.

- Big speedup by allocating frame objects with a single malloc() call.
The Python/C API for frames is changed (you shouldn't be using this
anyway).

- Significant speedup by inlining some common opcodes for common operand 
types (e.g.  i+i, i-i, and list[i]).  Fredrik Lundh.

- Small speedup by reordering the method tables of some common
objects (e.g. list.append is now first).

- Big optimization to the read() method of file objects.  A read()
without arguments now attempts to use fstat to allocate a buffer of
the right size; for pipes and sockets, it will fall back to doubling
the buffer size.  While that the improvement is real on all systems,
it is most dramatic on Windows.


Documentation
-------------

- Many new pieces of library documentation were contributed, mostly by
Andrew Kuchling.  Even cmath is now documented!  There's also a
chapter of the library manual, "libundoc.tex", which provides a
listing of all undocumented modules, plus their status (e.g. internal,
obsolete, or in need of documentation).  Also contributions by Sue
Williams, Skip Montanaro, and some module authors who succumbed to
pressure to document their own contributed modules :-).  Note that
printing the documentation now kills fewer trees -- the margins have
been reduced.

- I have started documenting the Python/C API. Unfortunately this project 
hasn't been completed yet.  It will be complete before the final release of 
Python 1.5, though.  At the moment, it's better to read the LaTeX source 
than to attempt to run it through LaTeX and print the resulting dvi file.

- The posix module (and hence os.py) now has doc strings!  Thanks to Neil 
Schemenauer.  I received a few other contributions of doc strings.  In most 
other places, doc strings are still wishful thinking...


Language changes
----------------

- Private variables with leading double underscore are now a permanent 
feature of the language.  (These were experimental in release 1.4.  I have 
favorable experience using them; I can't label them "experimental" 
forever.)

- There's new string literal syntax for "raw strings".  Prefixing a string 
literal with the letter r (or R) disables all escape processing in the 
string; for example, r'\n' is a two-character string consisting of a 
backslash followed by the letter n.  This combines with all forms of string 
quotes; it is actually useful for triple quoted doc strings which might 
contain references to \n or \t.  An embedded quote prefixed with a 
backslash does not terminate the string, but the backslash is still 
included in the string; for example, r'\'' is a two-character string 
consisting of a backslash and a quote.  (Raw strings are also 
affectionately known as Robin strings, after their inventor, Robin 
Friedrich.)

- There's a simple assert statement, and a new exception
AssertionError.  For example, ``assert foo > 0'' is equivalent to ``if
not foo > 0: raise AssertionError''.  Sorry, the text of the asserted
condition is not available; it would be too complicated to generate
code for this (since the code is generated from a parse tree).
However, the text is displayed as part of the traceback!

- The raise statement has a new feature: when using "raise SomeClass,
somevalue" where somevalue is not an instance of SomeClass, it
instantiates SomeClass(somevalue).  In 1.5a4, if somevalue is an
instance of a *derived* class of SomeClass, the exception class raised
is set to somevalue.__class__, and SomeClass is ignored after that.

- Duplicate keyword arguments are now detected at compile time;
f(a=1,a=2) is now a syntax error.


Changes to builtin features
---------------------------

- There's a new exception FloatingPointError (used only by Lee Busby's
patches to catch floating point exceptions, at the moment).

- The obsolete exception ConflictError (presumably used by the long
obsolete access statement) has been deleted.

- There's a new function sys.exc_info() which returns the tuple 
(sys.exc_type, sys.exc_value, sys.exc_traceback) in a thread-safe way.

- There's a new variable sys.executable, pointing to the executable file 
for the Python interpreter.

- The sort() methods for lists no longer uses the C library qsort(); I
wrote my own quicksort implementation, with lots of help (in the form
of a kind of competition) from Tim Peters.  This solves a bug in
dictionary comparisons on some Solaris versions when Python is built
with threads, and makes sorting lists even faster.

- The semantics of comparing two dictionaries have changed, to make
comparison of unequal dictionaries faster.  A shorter dictionary is
always considered smaller than a larger dictionary.  For dictionaries
of the same size, the smallest differing element determines the
outcome (which yields the same results as before in this case, without
explicit sorting).  Thanks to Aaron Watters for suggesting something
like this.

- The semantics of try-except have changed subtly so that calling a
function in an exception handler that itself raises and catches an
exception no longer overwrites the sys.exc_* variables.  This also
alleviates the problem that objects referenced in a stack frame that
caught an exception are kept alive until another exception is caught
-- the sys.exc_* variables are restored to their previous value when
returning from a function that caught an exception.

- There's a new "buffer" interface.  Certain objects (e.g. strings and
arrays) now support the "buffer" protocol.  Buffer objects are acceptable 
whenever formerly a string was required for a write operation; mutable 
buffer objects can be the target of a read operation using the call
f.readinto(buffer).  A cool feature is that regular expression matching now 
also work on array objects.  Contribution by Jack Jansen.  (Needs 
documentation.)

- String interning: dictionary lookups are faster when the lookup
string object is the same object as the key in the dictionary, not
just a string with the same value.  This is done by having a pool of
"interned" strings.  Most names generated by the interpreter are now
automatically interned, and there's a new built-in function intern(s)
that returns the interned version of a string.  Interned strings are
not a different object type, and interning is totally optional, but by
interning most keys a speedup of about 15% was obtained for the
pystone benchmark.

- Dictionary objects have several new methods; clear() and copy() have
the obvious semantics, while update(d) merges the contents of another
dictionary d into this one, overriding existing keys.  The dictionary
implementation file is now called dictobject.c rather than the
confusing mappingobject.c.

- The intrinsic function dir() is much smarter; it looks in __dict__,
__members__ and __methods__.

- The intrinsic functions int(), long() and float() can now take a
string argument and then do the same thing as string.atoi(),
string.atol(), and string.atof().  No second 'base' argument is
allowed, and complex() does not take a string (nobody cared enough).

- When a module is deleted, its globals are now deleted in two phases.
In the first phase, all variables whose name begins with exactly one
underscore are replaced by None; in the second phase, all variables
are deleted.  This makes it possible to have global objects whose
destructors depend on other globals.  The deletion order within each
phase is still random.

- It is no longer an error for a function to be called without a
global variable __builtins__ -- an empty directory will be provided
by default.

- Guido's corollary to the "Don Beaudry hook": it is now possible to
do metaprogramming by using an instance as a base class.  Not for the
faint of heart; and undocumented as yet, but basically if a base class
is an instance, its class will be instantiated to create the new
class.  Jim Fulton will love it -- it also works with instances of his
"extension classes", since it is triggered by the presence of a
__class__ attribute on the purported base class.  See
Demo/metaclasses/index.html for an explanation and see that directory
for examples.

- Another change is that the Don Beaudry hook is now invoked when
*any* base class is special.  (Up to 1.5a3, the *last* special base
class is used; in 1.5a4, the more rational choice of the *first*
special base class is used.)

- New optional parameter to the readlines() method of file objects.
This indicates the number of bytes to read (the actual number of bytes
read will be somewhat larger due to buffering reading until the end of
the line).  Some optimizations have also been made to speed it up (but
not as much as read()).

- Complex numbers no longer have the ".conj" pseudo attribute; use
z.conjugate() instead, or complex(z.real, -z.imag).  Complex numbers
now *do* support the __members__ and __methods__ special attributes.

- The complex() function now looks for a __complex__() method on class
instances before giving up.

- Long integers now support arbitrary shift counts, so you can now
write 1L<<1000000, memory permitting.  (Python 1.4 reports "outrageous
shift count for this.)

- The hex() and oct() functions have been changed so that for regular
integers, they never emit a minus sign.  For example, on a 32-bit
machine, oct(-1) now returns '037777777777' and hex(-1) returns
'0xffffffff'.  While this may seem inconsistent, it is much more
useful.  (For long integers, a minus sign is used as before, to fit
the result in memory :-)

- The hash() function computes better hashes for several data types,
including strings, floating point numbers, and complex numbers.


New extension modules
---------------------

- New extension modules cStringIO.c and cPickle.c, written by Jim
Fulton and other folks at Digital Creations.  These are much more
efficient than their Python counterparts StringIO.py and pickle.py,
but don't support subclassing.  cPickle.c clocks up to 1000 times
faster than pickle.py; cStringIO.c's improvement is less dramatic but
still significant.

- New extension module zlibmodule.c, interfacing to the free zlib
library (gzip compatible compression).  There's also a module gzip.py
which provides a higher level interface.  Written by Andrew Kuchling
and Jeremy Hylton.

- New module readline; see the "miscellaneous" section above.

- New Unix extension module resource.c, by Jeremy Hylton, provides
access to getrlimit(), getrusage(), setrusage(), getpagesize(), and
related symbolic constants.

- New extension puremodule.c, by Barry Warsaw, which interfaces to the
Purify(TM) C API.  See also the file Misc/PURIFY.README.  It is also
possible to enable Purify by simply setting the PURIFY Makefile
variable in the Modules/Setup file.


Changes in extension modules
----------------------------

- The struct extension module has several new features to control byte
order and word size.  It supports reading and writing IEEE floats even
on platforms where this is not the native format.  It uses uppercase
format codes for unsigned integers of various sizes (always using
Python long ints for 'I' and 'L'), 's' with a size prefix for strings,
and 'p' for "Pascal strings" (with a leading length byte, included in
the size; blame Hannu Krosing; new in 1.5a4).  A prefix '>' forces
big-endian data and '<' forces little-endian data; these also select
standard data sizes and disable automatic alignment (use pad bytes as
needed).

- The array module supports uppercase format codes for unsigned data
formats (like the struct module).

- The fcntl extension module now exports the needed symbolic
constants.  (Formerly these were in FCNTL.py which was not available
or correct for all platforms.)

- The extension modules dbm, gdbm and bsddb now check that the
database is still open before making any new calls.

- The dbhash module is no more.  Use bsddb instead.  (There's a third
party interface for the BSD 2.x code somewhere on the web; support for
bsddb will be deprecated.)

- The gdbm module now supports a sync() method.

- The socket module now has some new functions: getprotobyname(), and
the set {ntoh,hton}{s,l}().

- Various modules now export their type object: socket.SocketType,
array.ArrayType.

- The socket module's accept() method now returns unknown addresses as
a tuple rather than raising an exception.  (This can happen in
promiscuous mode.)  Theres' also a new function getprotobyname().

- The pthread support for the thread module now works on most platforms.

- STDWIN is now officially obsolete.  Support for it will eventually
be removed from the distribution.

- The binascii extension module is now hopefully fully debugged.
(XXX Oops -- Fredrik Lundh promised me a uuencode fix that I never
received.)

- audioop.c: added a ratecv() function; better handling of overflow in
add().

- posixmodule.c: now exports the O_* flags (O_APPEND etc.).  On
Windows, also O_TEXT and O_BINARY.  The 'error' variable (the
exception is raises) is renamed -- its string value is now "os.error",
so newbies don't believe they have to import posix (or nt) to catch
it when they see os.error reported as posix.error.  The execve()
function now accepts any mapping object for the environment.

- A new version of the al (audio library) module for SGI was
contributed by Sjoerd Mullender.

- The regex module has a new function get_syntax() which retrieves the
syntax setting set by set_syntax().  The code was also sanitized,
removing worries about unclean error handling.  See also below for its
successor, re.py.

- The "new" module (which creates new objects of various types) once
again has a fully functioning new.function() method.  Dangerous as
ever!  Also, new.code() has several new arguments.

- A problem has been fixed in the rotor module: on systems with signed
characters, rotor-encoded data was not portable when the key contained
8-bit characters.  Also, setkey() now requires its argument rather
than having broken code to default it.

- The sys.builtin_module_names variable is now a tuple.  Another new
variables in sys is sys.executable (the full path to the Python
binary, if known).

- The specs for time.strftime() have undergone some revisions.  It
appears that not all format characters are supported in the same way
on all platforms.  Rather than reimplement it, we note these
differences in the documentation, and emphasize the shared set of
features.  There's also a thorough test set (that occasionally finds
problems in the C library implementation, e.g. on some Linuxes),
thanks to Skip Montanaro.

- The nis module seems broken when used with NIS+; unfortunately
nobody knows how to fix it.  It should still work with old NIS.


New library modules
-------------------

- New (still experimental) Perl-style regular expression module,
re.py, which uses a new interface for matching as well as a new
syntax; the new interface avoids the thread-unsafety of the regex
interface.  This comes with a helper extension reopmodule.c and vastly
rewritten regexpr.c.  Most work on this was done by Jeffrey Ollie, Tim
Peters, and Andrew Kuchling.  See the documentation libre.tex.  In
1.5, the old regex module is still fully supported; in the future, it
will become obsolete.

- New module gzip.py; see zlib above.

- New module keyword.py exports knowledge about Python's built-in
keywords.  (New version by Ka-Ping Yee.)

- New module pprint.py (with documentation) which supports
pretty-printing of lists, tuples, & dictionaries recursively.  By Fred
Drake.

- New module code.py.  The function code.compile_command() can
determine whether an interactively entered command is complete or not,
distinguishing incomplete from invalid input.  (XXX Unfortunately,
this seems broken at this moment, and I don't have the time to fix
it.  It's probably better to add an explicit interface to the parser
for this.)

- There is now a library module xdrlib.py which can read and write the
XDR data format as used by Sun RPC, for example.  It uses the struct
module.


Changes in library modules
--------------------------

- Module codehack.py is now completely obsolete.

- The pickle.py module has been updated to make it compatible with the
new binary format that cPickle.c produces.  By default it produces the
old all-ASCII format compatible with the old pickle.py, still much
faster than pickle.py; it will read both formats automatically.  A few
other updates have been made.

- A new helper module, copy_reg.py, is provided to register extensions
to the pickling code.

- Revamped module tokenize.py is much more accurate and has an
interface that makes it a breeze to write code to colorize Python
source code.  Contributed by Ka-Ping Yee.

- In ihooks.py, ModuleLoader.load_module() now closes the file under
all circumstances.

- The tempfile.py module has a new class, TemporaryFile, which creates
an open temporary file that will be deleted automatically when
closed.  This works on Windows and MacOS as well as on Unix.  (Jim
Fulton.)

- Changes to the cgi.py module: Most imports are now done at the
top of the module, which provides a speedup when using ni (Jim
Fulton).  The problem with file upload to a Windows platform is solved
by using the new tempfile.TemporaryFile class; temporary files are now
always opened in binary mode (Jim Fulton).  The cgi.escape() function
now takes an optional flag argument that quotes '"' to '"'.  It
is now possible to invoke cgi.py from a command line script, to test
cgi scripts more easily outside an http server.  There's an optional
limit to the size of uploads to POST (Skip Montanaro).  Added a
'strict_parsing' option to all parsing functions (Jim Fulton).  The
function parse_qs() now uses urllib.unquote() on the name as well as
the value of fields (Clarence Gardner).  The FieldStorage class now
has a __len__() method.

- httplib.py: the socket object is no longer closed; all HTTP/1.*
responses are now accepted; and it is now thread-safe (by not using
the regex module).

- BaseHTTPModule.py: treat all HTTP/1.* versions the same.

- The popen2.py module is now rewritten using a class, which makes
access to the standard error stream and the process id of the
subprocess possible.

- Added timezone support to the rfc822.py module, in the form of a
getdate_tz() method and a parsedate_tz() function; also a mktime_tz().
Also added recognition of some non-standard date formats, by Lars
Wirzenius, and RFC 850 dates (Chris Lawrence).

- mhlib.py: various enhancements, including almost compatible parsing
of message sequence specifiers without invoking a subprocess.  Also
added a createmessage() method by Lars Wirzenius.

- The StringIO.StringIO class now supports readline(nbytes).  (Lars 
Wirzenius.)  (Of course, you should be using cStringIO for performance.)

- UserDict.py supports the new dictionary methods as well.

- Improvements for whrandom.py by Tim Peters: use 32-bit arithmetic to
speed it up, and replace 0 seed values by 1 to avoid degeneration.
A bug was fixed in the test for invalid arguments.

- Module ftplib.py: added support for parsing a .netrc file (Fred
Drake).  Also added an ntransfercmd() method to the FTP class, which
allows access to the expected size of a transfer when available, and a
parse150() function to the module which parses the corresponding 150
response.

- urllib.py: the ftp cache is now limited to 10 entries.  Added
quote_plus() and unquote_plus() functions which are like quote() and
unquote() but also replace spaces with '+' or vice versa, for
encoding/decoding CGI form arguments.  Catch all errors from the ftp
module.  HTTP requests now add the Host: header line.  The proxy
variable names are now mapped to lower case, for Windows.  The
spliturl() function no longer erroneously throws away all data past
the first newline.  The basejoin() function now intereprets "../"
correctly.  I *believe* that the problems with "exception raised in
__del__" under certain circumstances have been fixed (mostly by
changes elsewher in the interpreter).

- In urlparse.py, there is a cache for results in urlparse.urlparse();
its size limit is set to 20.  Also, new URL schemes shttp, https, and
snews are "supported".

- shelve.py: use cPickle and cStringIO when available.  Also added
a sync() method, which calls the database's sync() method if there is
one.

- The mimetools.py module now uses the available Python modules for
decoding quoted-printable, uuencode and base64 formats, rather than
creating a subprocess.

- The python debugger (pdb.py, and its base class bdb.py) now support
conditional breakpoints.  See the docs.

- The modules base64.py, uu.py and quopri.py can now be used as simple
command line utilities.

- Various small fixes to the nntplib.py module that I can't bother to
document in detail.

- Sjoerd Mullender's mimify.py module now supports base64 encoding and 
includes functions to handle the funny encoding you sometimes see in mail 
headers.  It is now documented.

- mailbox.py: Added BabylMailbox.  Improved the way the mailbox is
gotten from the environment.

- Many more modules now correctly open files in binary mode when this
is necessary on non-Unix platforms.

- The copying functions in the undocumented module shutil.py are
smarter.

- The Writer classes in the formatter.py module now have a flush()
method.

- The sgmllib.py module accepts hyphens and periods in the middle of
attribute names.  While this is against the SGML standard, there is
some HTML out there that uses this...

- The interface for the Python bytecode disassembler module, dis.py,
has been enhanced quite a bit.  There's now one main function,
dis.dis(), which takes almost any kind of object (function, module,
class, instance, method, code object) and disassembles it; without
arguments it disassembles the last frame of the last traceback.  The
other functions have changed slightly, too.

- The imghdr.py module recognizes new image types: BMP, PNG.

- The string.py module has a new function replace(str, old, new,
[maxsplit]) which does substring replacements.  It is actually
implemented in C in the strop module.  The functions [r]find() an
[r]index() have an optional 4th argument indicating the end of the
substring to search, alsoo implemented by their strop counterparts.
(Remember, never import strop -- import string uses strop when
available with zero overhead.)

- The string.join() function now accepts any sequence argument, not
just lists and tuples.

- The string.maketrans() requires its first two arguments to be
present.  The old version didn't require them, but there's not much
point without them, and the documentation suggests that they are
required, so we fixed the code to match the documentation.

- The regsub.py module has a function clear_cache(), which clears its
internal cache of compiled regular expressions.  Also, the cache now
takes the current syntax setting into account.  (However, this module
is now obsolete -- use the sub() or subn() functions or methods in the
re module.)

- The undocumented module Complex.py has been removed, now that Python
has built-in complex numbers.  A similar module remains as
Demo/classes/Complex.py, as an example.


Changes to the build process
----------------------------

- The way GNU readline is configured is totally different.  The
--with-readline configure option is gone.  It is now an extension
module, which may be loaded dynamically.  You must enable it (and
specify the correct linraries to link with) in the Modules/Setup file.
Importing the module installs some hooks which enable command line
editing.  When the interpreter shell is invoked interactively, it
attempts to import the readline module; when this fails, the default
input mechanism is used.  The hook variables are PyOS_InputHook and
PyOS_ReadlineFunctionPointer.  (Code contributed by Lee Busby, with
ideas from William Magro.)

- New build procedure: a single library, libpython1.5.a, is now built,
which contains absolutely everything except for a one-line main()
program (which calls Py_Main(argc, argv) to start the interpreter
shell).  This makes life much simpler for applications that need to
embed Python.  The serial number of the build is now included in the
version string (sys.version).

- As far as I can tell, neither gcc -Wall nor the Microsoft compiler
emits a single warning any more when compiling Python.

- A number of new Makefile variables have been added for special
situations, e.g. LDLAST is appended to the link command.  These are
used by editing the Makefile or passing them on the make command
line.

- A set of patches from Lee Busby has been integrated that make it
possible to catch floating point exceptions.  Use the configure option
--with-fpectl to enable the patches; the extension modules fpectl and
fpetest provide control to enable/disable and test the feature,
respectively.

- The support for shared libraries under AIX is now simpler and more
robust.  Thanks to Vladimir Marangozov for revamping his own patches!

- The Modules/makesetup script now reads a file Setup.local as well as
a file Setup.  Most changes to the Setup script can be done by editing
Setup.local instead, which makes it easier to carry a particular setup
over from one release to the next.

- The Modules/makesetup script now copies any "include" lines it
encounters verbatim into the output Makefile.  It also recognizes .cxx
and .cpp as C++ source files.

- The configure script is smarter about C compiler options; e.g. with
gcc it uses -O2 and -g when possible, and on some other platforms it
uses -Olimit 1500 to avoid a warning from the optimizer about the main
loop in ceval.c (which has more than 1000 basic blocks).

- The configure script now detects whether malloc(0) returns a NULL
pointer or a valid block (of length zero).  This avoids the nonsense
of always adding one byte to all malloc() arguments on most platforms.

- The configure script has a new option, --with-dec-threads, to enable
DEC threads on DEC Alpha platforms.  Also, --with-threads is now an
alias for --with-thread (this was the Most Common Typo in configure
arguments).

- Many changes in Doc/Makefile; amongst others, latex2html is now used
to generate HTML from all latex documents.


Change to the Python/C API
--------------------------

- Because some interfaces have changed, the PYTHON_API macro has been
bumped.  Most extensions built for the old API version will still run,
but I can't guarantee this.  Python prints a warning message on
version mismatches; it dumps core when the version mismatch causes a
serious problem :-)

- I've completed the Grand Renaming, with the help of Roger Masse and
Barry Warsaw.  This makes reading or debugging the code much easier.
Many other unrelated code reorganizations have also been carried out.
The allobjects.h header file is gone; instead, you would have to
include Python.h followed by rename2.h.  But you're better off running
Tools/scripts/fixcid.py -s Misc/RENAME on your source, so you can omit
the rename2.h; it will disappear in the next release.

- Various and sundry small bugs in the "abstract" interfaces have been
fixed.  Thanks to all the (involuntary) testers of the Python 1.4
version!  Some new functions have been added, e.g. PySequence_List(o),
equivalent to list(o) in Python.

- New API functions PyLong_FromUnsignedLong() and
PyLong_AsUnsignedLong().

- The API functions in the file cgensupport.c are no longer
supported.  This file has been moved to Modules and is only ever
compiled when the SGI specific 'gl' module is built.

- PyObject_Compare() can now raise an exception.  Check with
PyErr_Occurred().  The comparison function in an object type may also
raise an exception.

- The slice interface uses an upper bound of INT_MAX when no explicit
upper bound is given (e.x. for a[1:]).  It used to ask the object for
its length and do the calculations.

- Support for multiple independent interpreters.  See Doc/api.tex,
functions Py_NewInterpreter() and Py_EndInterpreter().  Since the
documentation is incomplete, also see the new Demo/pysvr example
(which shows how to use these in a threaded application) and the
source code.

- There is now a Py_Finalize() function which "de-initializes"
Python.  It is possible to completely restart the interpreter
repeatedly by calling Py_Finalize() followed by Py_Initialize().  A
change of functionality in Py_Initialize() means that it is now a
fatal error to call it while the interpreter is already initialized.
The old, half-hearted Py_Cleanup() routine is gone.  Use of Py_Exit()
is deprecated (it is nothing more than Py_Finalize() followed by
exit()).

- There are no known memory leaks left.  While Py_Finalize() doesn't
free *all* allocated memory (some of it is hard to track down),
repeated calls to Py_Finalize() and Py_Initialize() do not create
unaccessible heap blocks.

- There is now explicit per-thread state.  (Inspired by, but not the
same as, Greg Stein's free threading patches.)

- There is now better support for threading C applications.  There are
now explicit APIs to manipulate the interpreter lock.  Read the source
or the Demo/pysvr example; the new functions are
PyEval_{Acquire,Release}{Lock,Thread}().

- The test macro DEBUG has changed to Py_DEBUG, to avoid interference
with other libraries' DEBUG macros.  Likewise for any other test
macros that didn't yet start with Py_.

- New wrappers around malloc() and friends: Py_Malloc() etc. call
malloc() and call PyErr_NoMemory() when it fails; PyMem_Malloc() call
just malloc().  Use of these wrappers could be essential if multiple
memory allocators exist (e.g. when using certain DLL setups under
Windows).  (Idea by Jim Fulton.)

- New C API PyImport_Import() which uses whatever __import__() hook
that is installed for the current execution environment.  By Jim
Fulton.

- It is now possible for an extension module's init function to fail
non-fatally, by calling one of the PyErr_* functions and returning.

- The PyInt_AS_LONG() and PyFloat_AS_DOUBLE() macros now cast their
argument to the proper type, like the similar PyString macros already
did.  (Suggestion by Marc-Andre Lemburg.)  Similar for PyList_GET_SIZE
and PyList_GET_ITEM.

- Some of the Py_Get* function, like Py_GetVersion() (but not yet
Py_GetPath()) are now declared as returning a const char *.  (More
should follow.)

- Changed the run-time library to check for exceptions after object
comparisons.  PyObject_Compare() can now return an exception; use
PyErr_Occurred() to check (there is *no* special return value).

- PyFile_WriteString() and Py_Flushline() now return error indicators
instead of clearing exceptions.  This fixes an obscure bug where using
these would clear a pending exception, discovered by Just van Rossum.

- There's a new function, PyArg_ParseTupleAndKeywords(), which parses
an argument list including keyword arguments.  Contributed by Geoff
Philbrick.

- PyArg_GetInt() is gone.

- It's no longer necessary to include graminit.h when calling one of
the extended parser API functions.  The three public grammar start
symbols are now in Python.h as Py_single_input, Py_file_input, and
Py_eval_input.

- The CObject interface has a new function,
PyCObject_Import(module, name).  It calls PyCObject_AsVoidPtr()
on the object referenced by "module.name".


Tkinter
-------

- On popular demand, _tkinter once again installs a hook for readline
that processes certain Tk events while waiting for the user to type
(using PyOS_InputHook).

- A patch by Craig McPheeters plugs the most obnoxious memory leaks,
caused by command definitions referencing widget objects beyond their
lifetime.

- New standard dialog modules: tkColorChooser.py, tkCommonDialog.py,
tkMessageBox.py, tkFileDialog.py, tkSimpleDialog.py These interface
with the new Tk dialog scripts, and provide more "native platform"
style file selection dialog boxes on some platforms.  Contributed by
Fredrik Lundh.

- Tkinter.py: when the first Tk object is destroyed, it sets the
hiddel global _default_root to None, so that when another Tk object is
created it becomes the new default root.  Other miscellaneous
changes and fixes.

- The Image class now has a configure method.

- Added a bunch of new winfo options to Tkinter.py; we should now be
up to date with Tk 4.2.  The new winfo options supported are:
mananger, pointerx, pointerxy, pointery, server, viewable, visualid,
visualsavailable.

- The broken bind() method on Canvas objects defined in the Canvas.py
module has been fixed.  The CanvasItem and Group classes now also have
an unbind() method.

- The problem with Tkinter.py falling back to trying to import
"tkinter" when "_tkinter" is not found has been fixed -- it no longer
tries "tkinter", ever.  This makes diagnosing the problem "_tkinter
not configured" much easier and will hopefully reduce the newsgroup
traffic on this topic.

- The ScrolledText module once again supports the 'cnf' parameter, to
be compatible with the examples in Mark Lutz' book (I know, I know,
too late...)

- The _tkinter.c extension module has been revamped.  It now support
Tk versions 4.1 through 8.0; support for 4.0 has been dropped.  It
works well under Windows and Mac (with the latest Tk ports to those
platforms).  It also supports threading -- it is safe for one
(Python-created) thread to be blocked in _tkinter.mainloop() while
other threads modify widgets.  To make the changes visible, those
threads must use update_idletasks()method.  (The patch for threading
in 1.5a3 was broken; in 1.5a4, it is back in a different version,
which requires access to the Tcl sources to get it to work -- hence it
is disabled by default.)

- A bug in _tkinter.c has been fixed, where Split() with a string
containing an unmatched '"' could cause an exception or core dump.

- Unfortunately, on Windows and Mac, Tk 8.0 no longer supports
CreateFileHandler, so _tkinter.createfilehandler is not available on
those platforms when using Tk 8.0 or later.  I will have to rethink
how to interface with Tcl's lower-level event mechanism, or with its
channels (which are like Python's file-like objects).  Jack Jansen has
provided a fix for the Mac, so createfilehandler *is* actually
supported there; maybe I can adapt his fix for Windows.


Tools and Demos
---------------

- A new regression test suite is provided, which tests most of the
standard and built-in modules.  The regression test is run by invoking
the script Lib/test/regrtest.py.  Barry Warsaw wrote the test harnass;
he and Roger Masse contributed most of the new tests.

- New tool: faqwiz -- the CGI script that is used to maintain the
Python FAQ (http://grail.cnri.reston.va.us/cgi-bin/faqw.py).  In
Tools/faqwiz.

- New tool: webchecker -- a simple extensible web robot that, when
aimed at a web server, checks that server for dead links.  Available
are a command line utility as well as a Tkinter based GUI version.  In
Tools/webchecker.  A simplified version of this program is dissected
in my article in O'Reilly's WWW Journal, the issue on Scripting
Languages (Vol 2, No 2); Scripting the Web with Python (pp 97-120).
Includes a parser for robots.txt files by Skip Montanaro.

- New small tools: cvsfiles.py (prints a list of all files under CVS
n a particular directory tree), treesync.py (a rather Guido-specific
script to synchronize two source trees, one on Windows NT, the other
one on Unix under CVS but accessible from the NT box), and logmerge.py
(sort a collection of RCS or CVS logs by date).  In Tools/scripts.

- The freeze script now also works under Windows (NT).  Another
feature allows the -p option to be pointed at the Python source tree
instead of the installation prefix.  This was loosely based on part of
xfreeze by Sam Rushing and Bill Tutt.

- New examples (Demo/extend) that show how to use the generic
extension makefile (Misc/Makefile.pre.in).

- Tools/scripts/h2py.py now supports C++ comments.

- Tools/scripts/pystone.py script is upgraded to version 1.1; there
was a bug in version 1.0 (distributed with Python 1.4) that leaked
memory.  Also, in 1.1, the LOOPS variable is incremented to 10000.

- Demo/classes/Rat.py completely rewritten by Sjoerd Mullender.


Windows (NT and 95)
-------------------

- New project files for Developer Studio (Visual C++) 5.0 for Windows
NT (the old VC++ 4.2 Makefile is also still supported, but will
eventually be withdrawn due to its bulkiness).

- See the note on the new module search path in the "Miscellaneous" section 
above.

- Support for Win32s (the 32-bit Windows API under Windows 3.1) is
basically withdrawn.  If it still works for you, you're lucky.

- There's a new extension module, msvcrt.c, which provides various 
low-level operations defined in the Microsoft Visual C++ Runtime Library.  
These include locking(), setmode(), get_osfhandle(), set_osfhandle(), and 
console I/O functions like kbhit(), getch() and putch().

- The -u option not only sets the standard I/O streams to unbuffered
status, but also sets them in binary mode.  (This can also be done
using msvcrt.setmode(), by the way.)

- The, sys.prefix and sys.exec_prefix variables point to the directory 
where Python is installed, or to the top of the source tree, if it was run 
from there.

- The various os.path modules (posixpath, ntpath, macpath) now support
passing more than two arguments to the join() function, so
os.path.join(a, b, c) is the same as os.path.join(a, os.path.join(b,
c)).

- The ntpath module (normally used as os.path) supports ~ to $HOME 
expansion in expanduser().

- The freeze tool now works on Windows.

- See also the Tkinter category for a sad note on
_tkinter.createfilehandler().

- The truncate() method for file objects now works on Windows.

- Py_Initialize() is no longer called when the DLL is loaded.  You
must call it yourself.

- The time module's clock() function now has good precision through
the use of the Win32 API QueryPerformanceCounter().

- Mark Hammond will release Python 1.5 versions of PythonWin and his
other Windows specific code: the win32api extensions, COM/ActiveX
support, and the MFC interface.


Mac
---

- As always, the Macintosh port will be done by Jack Jansen.  He will
make a separate announcement for the Mac specific source code and the
binary distribution(s) when these are ready.


======================================================================


=====================================
==> Release 1.4 (October 25 1996) <==
=====================================

(Starting in reverse chronological order:)

- Changed disclaimer notice.

- Added SHELL=/bin/sh to Misc/Makefile.pre.in -- some Make versions
default to the user's login shell.

- In Lib/tkinter/Tkinter.py, removed bogus binding of  in Text
widget, and bogus bspace() function.

- In Lib/cgi.py, bumped __version__ to 2.0 and restored a truncated
paragraph.

- Fixed the NT Makefile (PC/vc40.mak) for VC 4.0 to set /MD for all
subprojects, and to remove the (broken) experimental NumPy
subprojects.

- In Lib/py_compile.py, cast mtime to long() so it will work on Mac
(where os.stat() returns mtimes as floats.)
- Set self.rfile unbuffered (like self.wfile) in SocketServer.py, to
fix POST in CGIHTTPServer.py.

- Version 2.83 of Misc/python-mode.el for Emacs is included.

- In Modules/regexmodule.c, fixed symcomp() to correctly handle a new
group starting immediately after a group tag.

- In Lib/SocketServer.py, changed the mode for rfile to unbuffered.

- In Objects/stringobject.c, fixed the compare function to do the
first char comparison in unsigned mode, for consistency with the way
other characters are compared by memcmp().

- In Lib/tkinter/Tkinter.py, fixed Scale.get() to support floats.

- In Lib/urllib.py, fix another case where openedurl wasn't set.

(XXX Sorry, the rest is in totally random order.  No time to fix it.)

- SyntaxError exceptions detected during code generation
(e.g. assignment to an expression) now include a line number.

- Don't leave trailing / or \ in script directory inserted in front of
sys.path.

- Added a note to Tools/scripts/classfix.py abouts its historical
importance.

- Added Misc/Makefile.pre.in, a universal Makefile for extensions
built outside the distribution.

- Rewritten Misc/faq2html.py, by Ka-Ping Yee.

- Install shared modules with mode 555 (needed for performance on some
platforms).

- Some changes to standard library modules to avoid calling append()
with more than one argument -- while supported, this should be
outlawed, and I don't want to set a bad example.

- bdb.py (and hence pdb.py) supports calling run() with a code object
instead of a code string.

- Fixed an embarrassing bug cgi.py which prevented correct uploading
of binary files from Netscape (which doesn't distinguish between
binary and text files).  Also added dormant logging support, which
makes it easier to debug the cgi module itself.

- Added default writer to constructor of NullFormatter class.

- Use binary mode for socket.makefile() calls in ftplib.py.

- The ihooks module no longer "installs" itself upon import -- this
was an experimental feature that helped ironing out some bugs but that
slowed down code that imported it without the need to install it
(e.g. the rexec module).  Also close the file in some cases and add
the __file__ attribute to loaded modules.

- The test program for mailbox.py is now more useful.

- Added getparamnames() to Message class in mimetools.py -- it returns
the names of parameters to the content-type header.

- Fixed a typo in ni that broke the loop stripping "__." from names.

- Fix sys.path[0] for scripts run via pdb.py's new main program.

- profile.py can now also run a script, like pdb.

- Fix a small bug in pyclbr -- don't add names starting with _ when
emulating from ... import *.

- Fixed a series of embarrassing typos in rexec's handling of standard
I/O redirection.  Added some more "safe" built-in modules: cmath,
errno, operator.

- Fixed embarrassing typo in shelve.py.

- Added SliceType and EllipsisType to types.py.

- In urllib.py, added handling for error 301 (same as 302); added
geturl() method to get the URL after redirection.

- Fixed embarrassing typo in xdrlib.py.  Also fixed typo in Setup.in
for _xdrmodule.c and removed redundant #include from _xdrmodule.c.

- Fixed bsddbmodule.c to add binary mode indicator on platforms that
have it.  This should make it working on Windows NT.

- Changed last uses of #ifdef NT to #ifdef MS_WINDOWS or MS_WIN32,
whatever applies.  Also rationalized some other tests for various MS
platforms.

- Added the sources for the NT installer script used for Python
1.4beta3.  Not tested with this release, but better than nothing.

- A compromise in pickle's defenses against Trojan horses: a
user-defined function is now okay where a class is expected.  A
built-in function is not okay, to prevent pickling something that
will execute os.system("rm -f *") when unpickling.

- dis.py will print the name of local variables referenced by local
load/store/delete instructions.

- Improved portability of SimpleHTTPServer module to non-Unix
platform.

- The thread.h interface adds an extra argument to down_sema().  This
only affects other C code that uses thread.c; the Python thread module
doesn't use semaphores (which aren't provided on all platforms where
Python threads are supported).  Note: on NT, this change is not
implemented.

- Fixed some typos in abstract.h; corrected signature of
PyNumber_Coerce, added PyMapping_DelItem.  Also fixed a bug in
abstract.c's PyObject_CallMethod().

- apply(classname, (), {}) now works even if the class has no
__init__() method.

- Implemented complex remainder and divmod() (these would dump core!).
Conversion of complex numbers to int, long int or float now raises an
exception, since there is no meaningful way to do it without losing
information.

- Fixed bug in built-in complex() function which gave the wrong result
for two real arguments.

- Change the hash algorithm for strings -- the multiplier is now
1000003 instead of 3, which gives better spread for short strings.

- New default path for Windows NT, the registry structure now supports
default paths for different install packages.  (Mark Hammond -- the
next PythonWin release will use this.)

- Added more symbols to the python_nt.def file.

- When using GNU readline, set rl_readline_name to "python".

- The Ellipses built-in name has been renamed to Ellipsis -- this is
the correct singular form.  Thanks to Ka-Ping Yee, who saved us from
eternal embarrassment.

- Bumped the PYTHON_API_VERSION to 1006, due to the Ellipses ->
Ellipsis name change.

- Updated the library reference manual.  Added documentation of
restricted mode (rexec, Bastion) and the formatter module (for use
with the htmllib module).  Fixed the documentation of htmllib
(finally).

- The reference manual is now maintained in FrameMaker.

- Upgraded scripts Doc/partparse.py and Doc/texi2html.py.

- Slight improvements to Doc/Makefile.

- Added fcntl.lockf(). This should be used for Unix file locking
instead of the posixfile module; lockf() is more portable.

- The getopt module now supports long option names, thanks to Lars
Wizenius.

- Plenty of changes to Tkinter and Canvas, mostly due to Fred Drake
and Nils Fischbeck.

- Use more bits of time.time() in whrandom's default seed().

- Performance hack for regex module's regs attribute.

- Don't close already closed socket in socket module.

- Correctly handle separators containing embedded nulls in
strop.split, strop.find and strop.rfind.  Also added more detail to
error message for strop.atoi and friends.

- Moved fallback definition for hypot() to Python/hypot.c.

- Added fallback definition for strdup, in Python/strdup.c.

- Fixed some bugs where a function would return 0 to indicate an error
where it should return -1.

- Test for error returned by time.localtime(), and rationalized its MS
tests.

- Added Modules/Setup.local file, which is processed after Setup.

- Corrected bug in toplevel Makefile.in -- execution of regen script
would not use the right PATH and PYTHONPATH.

- Various and sundry NeXT configuration changes (sigh).

- Support systems where libreadline needs neither termcap nor curses.

- Improved ld_so_aix script and python.exp file (for AIX).

- More stringent test for working  in configure script.

- Removed Demo/www subdirectory -- it was totally out of date.

- Improved demos and docs for Fred Drake's parser module; fixed one
typo in the module itself.


=========================================
==> Release 1.4beta3 (August 26 1996) <==
=========================================


(XXX This is less readable that it should.  I promise to restructure
it for the final 1.4 release.)


What's new in 1.4beta3 (since beta2)?
-------------------------------------

- Name mangling to implement a simple form of class-private variables.
A name of the form "__spam" can't easily be used outside the class.
(This was added in 1.4beta3, but left out of the 1.4beta3 release
message.)

- In urllib.urlopen(): HTTP URLs containing user:passwd@host are now
handled correctly when using a proxy server.

- In ntpath.normpath(): don't truncate to 8+3 format.

- In mimetools.choose_boundary(): don't die when getuid() or getpid()
aren't defined.

- Module urllib: some optimizations to (un)quoting.

- New module MimeWriter for writing MIME documents.

- More changes to formatter module.

- The freeze script works once again and is much more robust (using
sys.prefix etc.).  It also supports a -o option to specify an
output directory.

- New module whichdb recognizes dbm, gdbm and bsddb/dbhash files.

- The Doc/Makefile targets have been reorganized somewhat to remove the 
insistence on always generating PostScript.

- The texinfo to html filter (Doc/texi2html.py) has been improved somewhat.

- "errors.h" has been renamed to "pyerrors.h" to resolve a long-standing 
name conflict on the Mac.

- Linking a module compiled with a different setting for Py_TRACE_REFS now 
generates a linker error rather than a core dump.

- The cgi module has a new convenience function print_exception(), which 
formats a python exception using HTML.  It also fixes a bug in the 
compatibility code and adds a dubious feature which makes it possible to 
have two query strings, one in the URL and one in the POST data.

- A subtle change in the unpickling of class instances makes it possible 
to unpickle in restricted execution mode, where the __dict__ attribute is 
not available (but setattr() is).

- Documentation for os.path.splitext() (== posixpath.splitext()) has been 
cleared up.  It splits at the *last* dot.

- posixfile locking is now also correctly supported on AIX.

- The tempfile module once again honors an initial setting of tmpdir.  It 
now works on Windows, too.

- The traceback module has some new functions to extract, format and print 
the active stack.

- Some translation functions in the urllib module have been made a little 
less sluggish.

- The addtag_* methods for Canvas widgets in Tkinter as well as in the 
separate Canvas class have been fixed so they actually do something 
meaningful.

- A tiny _test() function has been added to Tkinter.py.

- A generic Makefile for dynamically loaded modules is provided in the Misc 
subdirectory (Misc/gMakefile).

- A new version of python-mode.el for Emacs is provided.  See
http://www.python.org/ftp/emacs/pmdetails.html for details.  The
separate file pyimenu.el is no longer needed, imenu support is folded
into python-mode.el.

- The configure script can finally correctly find the readline library in a 
non-standard location.  The LDFLAGS variable is passed on the Makefiles 
from the configure script.

- Shared libraries are now installed as programs (i.e. with executable 
permission).  This is required on HP-UX and won't hurt on other systems.

- The objc.c module is no longer part of the distribution.  Objective-C 
support may become available as contributed software on the ftp site.

- The sybase module is no longer part of the distribution.  A much
improved sybase module is available as contributed software from the
ftp site.

- _tkinter is now compatible with Tcl 7.5 / Tk 4.1 patch1 on Windows and 
Mac (don't use unpatched Tcl/Tk!).  The default line in the Setup.in file 
now links with Tcl 7.5 / Tk 4.1 rather than 7.4/4.0.

- In Setup, you can now write "*shared*" instead of "*noconfig*", and you 
can use *.so and *.sl as shared libraries.

- Some more fidgeting for AIX shared libraries.

- The mpz module is now compatible with GMP 2.x.  (Not tested by me.)
(Note -- a complete replacement by Niels Mo"ller, called gpmodule, is
available from the contrib directory on the ftp site.)

- A warning is written to sys.stderr when a __del__ method raises an 
exception (formerly, such exceptions were completely ignored).

- The configure script now defines HAVE_OLD_CPP if the C preprocessor is 
incapable of ANSI style token concatenation and stringification.

- All source files (except a few platform specific modules) are once again 
compatible with K&R C compilers as well as ANSI compilers.  In particular,
ANSI-isms have been removed or made conditional in complexobject.c, 
getargs.c and operator.c.

- The abstract object API has three new functions, PyObject_DelItem, 
PySequence_DelItem, and PySequence_DelSlice.

- The operator module has new functions delitem and delslice, and the 
functions "or" and "and" are renamed to "or_" and "and_" (since "or" and 
"and" are reserved words).  ("__or__" and "__and__" are unchanged.)

- The environment module is no longer supported; putenv() is now a function 
in posixmodule (also under NT).

- Error in filter(, "") has been fixed.

- Unrecognized keyword arguments raise TypeError, not KeyError.

- Better portability, fewer bugs and memory leaks, fewer compiler warnings, 
some more documentation.

- Bug in float power boundary case (0.0 to the negative integer power) 
fixed.

- The test of negative number to the float power has been moved from the 
built-in pow() functin to floatobject.c (so complex numbers can yield the 
correct result).

- The bug introduced in beta2 where shared libraries loaded (using 
dlopen()) from the current directory would fail, has been fixed.

- Modules imported as shared libraries now also have a __file__ attribute, 
giving the filename from which they were loaded.  The only modules without 
a __file__ attribute now are built-in modules.

- On the Mac, dynamically loaded modules can end in either ".slb" or 
"..slb" where  is either "CFM68K" or "ppc".  The ".slb" 
extension should only be used for "fat" binaries.

- C API addition: marshal.c now supports 
PyMarshal_WriteObjectToString(object).

- C API addition: getargs.c now supports
PyArg_ParseTupleAndKeywords(args, kwdict, format, kwnames, ...)
to parse keyword arguments.

- The PC versioning scheme (sys.winver) has changed once again.  the 
version number is now "...", where the 
first three s are the Python version (e.g. "1.4.0" for Python 1.4, 
"1.4.1" for Python 1.4.1 -- the beta level is not included) and 
 is the four-digit PYTHON_API_VERSION (currently 1005).

- h2py.py accepts whitespace before the # in CPP directives

- On Solaris 2.5, it should now be possible to use either Posix threads or 
Solaris threads (XXX: how do you select which is used???).  (Note: the 
Python pthreads interface doesn't fully support semaphores yet -- anyone 
care to fix this?)

- Thread support should now work on AIX, using either DCE threads or 
pthreads.

- New file Demo/sockets/unicast.py

- Working Mac port, with CFM68K support, with Tk 4.1 support (though not 
both) (XXX)

- New project setup for PC port, now compatible with PythonWin, with 
_tkinter and NumPy support (XXX)

- New module site.py (XXX)

- New module xdrlib.py and optional support module _xdrmodule.c (XXX)

- parser module adapted to new grammar, complete w/ Doc & Demo (XXX)

- regen script fixed (XXX)

- new machdep subdirectories Lib/{aix3,aix4,next3_3,freebsd2,linux2} (XXX)

- testall now also tests math module (XXX)

- string.atoi c.s. now raise an exception for an empty input string.

- At last, it is no longer necessary to define HAVE_CONFIG_H in order to 
have config.h included at various places.

- Unrecognized keyword arguments now raise TypeError rather than KeyError.

- The makesetup script recognizes files with extension .so or .sl as
(shared) libraries.

- 'access' is no longer a reserved word, and all code related to its 
implementation is gone (or at least #ifdef'ed out).  This should make 
Python a little speedier too!

- Performance enhancements suggested by Sjoerd Mullender.  This includes 
the introduction of two new optional function pointers in type object, 
getattro and setattro, which are like getattr and setattr but take a 
string object instead of a C string pointer.

- New operations in string module: lstrip(s) and rstrip(s) strip whitespace 
only on the left or only on the right, A new optional third argument to 
split() specifies the maximum number of separators honored (so 
splitfields(s, sep, n) returns a list of at most n+1 elements).  (Since 
1.3, splitfields(s, None) is totally equivalent to split(s).)
string.capwords() has an optional second argument specifying the 
separator (which is passed to split()).

- regsub.split() has the same addition as string.split().  regsub.splitx(s, 
sep, maxsep) implements the functionality that was regsub.split(s, 1) in 
1.4beta2 (return a list containing the delimiters as well as the words).

- Final touch for AIX loading, rewritten Misc/AIX-NOTES.

- In Modules/_tkinter.c, when using Tk 4.1 or higher, use className
argument to _tkinter.create() to set Tcl's argv0 variable, so X
resources use the right resource class again.

- Add #undef fabs to Modules/mathmodule.c for macintosh.

- Added some macro renames for AIX in Modules/operator.c.

- Removed spurious 'E' from Doc/liberrno.tex.

- Got rid of some cruft in Misc/ (dlMakefile, pyimenu.el); added new
Misc/gMakefile and new version of Misc/python-mode.el.

- Fixed typo in Lib/ntpath.py (islink has "return false" which gives a
NameError).

- Added missing "from types import *" to Lib/tkinter/Canvas.py.

- Added hint about using default args for __init__ to pickle docs.

- Corrected typo in Inclide/abstract.h: PySequence_Lenth ->
PySequence_Length.

- Some improvements to Doc/texi2html.py.

- In Python/import.c, Cast unsigned char * in struct _frozen to char *
in calls to rds_object().

- In doc/ref4.tex, added note about scope of lambda bodies.

What's new in 1.4beta2 (since beta1)?
-------------------------------------

- Portability bug in the md5.h header solved.

- The PC build procedure now really works, and sets sys.platform to a
meaningful value (a few things were botched in beta 1).  Lib/dos_8x3
is now a standard part of the distribution (alas).

- More improvements to the installation procedure.  Typing "make install" 
now inserts the version number in the pathnames of almost everything 
installed, and creates the machine dependent modules (FCNTL.py etc.) if not 
supplied by the distribution.  (XXX There's still a problem with the latter 
because the "regen" script requires that Python is installed.  Some manual 
intervention may still be required.) (This has been fixed in 1.4beta3.)

- New modules: errno, operator (XXX).

- Changes for use with Numerical Python: builtin function slice() and
Ellipses object, and corresponding syntax:

	x[lo:hi:stride]		==	x[slice(lo, hi, stride)]
	x[a, ..., z]		==	x[(a, Ellipses, z)]

- New documentation for errno and cgi modules.

- The directory containing the script passed to the interpreter is
inserted in from of sys.path; "." is no longer a default path
component.

- Optional third string argument to string.translate() specifies
characters to delete.  New function string.maketrans() creates a
translation table for translate() or for regex.compile().

- Module posix (and hence module os under Unix) now supports putenv().
Moreover, module os is enhanced so that if putenv() is supported,
assignments to os.environ entries make the appropriate putenv() call.
(XXX the putenv() implementation can leak a small amount of memory per
call.)

- pdb.py can now be invoked from the command line to debug a script:
python pdb.py