1 This is Python version 2.5.1
2 ============================
4 Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007 Python Software
8 Copyright (c) 2000 BeOpen.com.
11 Copyright (c) 1995-2001 Corporation for National Research Initiatives.
14 Copyright (c) 1991-1995 Stichting Mathematisch Centrum.
21 See the file "LICENSE" for information on the history of this
22 software, terms & conditions for usage, and a DISCLAIMER OF ALL
25 This Python distribution contains no GNU General Public Licensed
26 (GPLed) code so it may be used in proprietary projects just like prior
27 Python distributions. There are interfaces to some GNU code but these
28 are entirely optional.
30 All trademarks referenced herein are property of their respective
34 What's new in this release?
35 ---------------------------
37 See the file "Misc/NEWS".
40 If you don't read instructions
41 ------------------------------
43 Congratulations on getting this far. :-)
45 To start building right away (on UNIX): type "./configure" in the
46 current directory and when it finishes, type "make". This creates an
47 executable "./python"; to install in /usr/local, first do "su root"
48 and then "make install".
50 The section `Build instructions' below is still recommended reading.
53 What is Python anyway?
54 ----------------------
56 Python is an interpreted, interactive object-oriented programming
57 language suitable (amongst other uses) for distributed application
58 development, scripting, numeric computing and system testing. Python
59 is often compared to Tcl, Perl, Java, JavaScript, Visual Basic or
60 Scheme. To find out more about what Python can do for you, point your
61 browser to http://www.python.org/.
64 How do I learn Python?
65 ----------------------
67 The official tutorial is still a good place to start; see
68 http://docs.python.org/ for online and downloadable versions, as well
69 as a list of other introductions, and reference documentation.
71 There's a quickly growing set of books on Python. See
72 http://wiki.python.org/moin/PythonBooks for a list.
78 All documentation is provided online in a variety of formats. In
79 order of importance for new users: Tutorial, Library Reference,
80 Language Reference, Extending & Embedding, and the Python/C API. The
81 Library Reference is especially of immense value since much of
82 Python's power is described there, including the built-in data types
85 All documentation is also available online at the Python web site
86 (http://docs.python.org/, see below). It is available online for
87 occasional reference, or can be downloaded in many formats for faster
88 access. The documentation is available in HTML, PostScript, PDF, and
89 LaTeX formats; the LaTeX version is primarily for documentation
90 authors, translators, and people with special formatting requirements.
92 Unfortunately, new-style classes (new in Python 2.2) have not yet been
93 integrated into Python's standard documentation. A collection of
94 pointers to what has been written is at:
96 http://www.python.org/doc/newstyle.html
102 New Python releases and related technologies are published at
103 http://www.python.org/. Come visit us!
105 There's also a Python community web site at
106 http://starship.python.net/.
109 Newsgroups and Mailing Lists
110 ----------------------------
112 Read comp.lang.python, a high-volume discussion newsgroup about
113 Python, or comp.lang.python.announce, a low-volume moderated newsgroup
114 for Python-related announcements. These are also accessible as
115 mailing lists: see http://www.python.org/community/lists.html for an
116 overview of these and many other Python-related mailing lists.
118 Archives are accessible via the Google Groups Usenet archive; see
119 http://groups.google.com/. The mailing lists are also archived, see
120 http://www.python.org/community/lists.html for details.
126 To report or search for bugs, please use the Python Bug
127 Tracker at http://sourceforge.net/bugs/?group_id=5470.
130 Patches and contributions
131 -------------------------
133 To submit a patch or other contribution, please use the Python Patch
134 Manager at http://sourceforge.net/patch/?group_id=5470. Guidelines
135 for patch submission may be found at http://www.python.org/patches/.
137 If you have a proposal to change Python, it's best to submit a Python
138 Enhancement Proposal (PEP) first. All current PEPs, as well as
139 guidelines for submitting a new PEP, are listed at
140 http://www.python.org/peps/.
146 For help, if you can't find it in the manuals or on the web site, it's
147 best to post to the comp.lang.python or the Python mailing list (see
148 above). If you specifically don't want to involve the newsgroup or
149 mailing list, send questions to help@python.org (a group of volunteers
150 who answer questions as they can). The newsgroup is the most
151 efficient way to ask public questions.
157 Before you can build Python, you must first configure it.
158 Fortunately, the configuration and build process has been automated
159 for Unix and Linux installations, so all you usually have to do is
160 type a few commands and sit back. There are some platforms where
161 things are not quite as smooth; see the platform specific notes below.
162 If you want to build for multiple platforms sharing the same source
163 tree, see the section on VPATH below.
165 Start by running the script "./configure", which determines your
166 system configuration and creates the Makefile. (It takes a minute or
167 two -- please be patient!) You may want to pass options to the
168 configure script -- see the section below on configuration options and
169 variables. When it's done, you are ready to run make.
171 To build Python, you normally type "make" in the toplevel directory.
172 If you have changed the configuration, the Makefile may have to be
173 rebuilt. In this case you may have to run make again to correctly
174 build your desired target. The interpreter executable is built in the
177 Once you have built a Python interpreter, see the subsections below on
178 testing and installation. If you run into trouble, see the next
181 Previous versions of Python used a manual configuration process that
182 involved editing the file Modules/Setup. While this file still exists
183 and manual configuration is still supported, it is rarely needed any
184 more: almost all modules are automatically built as appropriate under
185 guidance of the setup.py script, which is run by Make after the
186 interpreter has been built.
192 See also the platform specific notes in the next section.
194 If you run into other trouble, see the FAQ
195 (http://www.python.org/doc/faq) for hints on what can go wrong, and
198 If you rerun the configure script with different options, remove all
199 object files by running "make clean" before rebuilding. Believe it or
200 not, "make clean" sometimes helps to clean up other inexplicable
201 problems as well. Try it before sending in a bug report!
203 If the configure script fails or doesn't seem to find things that
204 should be there, inspect the config.log file.
206 If you get a warning for every file about the -Olimit option being no
207 longer supported, you can ignore it. There's no foolproof way to know
208 whether this option is needed; all we can do is test whether it is
209 accepted without error. On some systems, e.g. older SGI compilers, it
210 is essential for performance (specifically when compiling ceval.c,
211 which has more basic blocks than the default limit of 1000). If the
212 warning bothers you, edit the Makefile to remove "-Olimit 1500" from
215 If you get failures in test_long, or sys.maxint gets set to -1, you
216 are probably experiencing compiler bugs, usually related to
217 optimization. This is a common problem with some versions of gcc, and
218 some vendor-supplied compilers, which can sometimes be worked around
219 by turning off optimization. Consider switching to stable versions
220 (gcc 2.95.2, gcc 3.x, or contact your vendor.)
222 From Python 2.0 onward, all Python C code is ANSI C. Compiling using
223 old K&R-C-only compilers is no longer possible. ANSI C compilers are
224 available for all modern systems, either in the form of updated
225 compilers from the vendor, or one of the free compilers (gcc).
227 If "make install" fails mysteriously during the "compiling the library"
228 step, make sure that you don't have any of the PYTHONPATH or PYTHONHOME
229 environment variables set, as they may interfere with the newly built
230 executable which is compiling the library.
235 A number of features are not supported in Python 2.5 anymore. Some
236 support code is still present, but will be removed in Python 2.6.
237 If you still need to use current Python versions on these systems,
238 please send a message to python-dev@python.org indicating that you
239 volunteer to support this system. For a more detailed discussion
240 regarding no-longer-supported and resupporting platforms, as well
241 as a list of platforms that became or will be unsupported, see PEP 11.
243 More specifically, the following systems are not supported any
250 - Irix 4 and --with-sgi-dl
252 - Systems defining __d6_pthread_create (configure.in)
253 - Systems defining PY_PTHREAD_D4, PY_PTHREAD_D6,
254 or PY_PTHREAD_D7 in thread_pthread.h
255 - Systems using --with-dl-dld
256 - Systems using --without-universal-newlines
259 The following systems are still supported in Python 2.5, but
260 support will be dropped in 2.6:
261 - Systems using --with-wctype-functions
264 Warning on install in Windows 98 and Windows Me
265 -----------------------------------------------
267 Following Microsoft's closing of Extended Support for
268 Windows 98/ME (July 11, 2006), Python 2.6 will stop
269 supporting these platforms. Python development and
270 maintainability becomes easier (and more reliable) when
271 platform specific code targeting OSes with few users
272 and no dedicated expert developers is taken out. The
273 vendor also warns that the OS versions listed above
274 "can expose customers to security risks" and recommends
277 Platform specific notes
278 -----------------------
280 (Some of these may no longer apply. If you find you can build Python
281 on these platforms without the special directions mentioned here,
282 submit a documentation bug report to SourceForge (see Bug Reports
283 above) so we can remove them!)
286 GCC 4.2: There is a known incompatibility between Python and GCC,
287 where GCC 4.1 and later uses an interpretation of C
288 different to earlier GCC releases in an area where the C
289 specification has undefined behaviour (namely, integer arithmetic
290 involving -sys.maxint-1).
292 As a consequence, compiling Python with GCC 4.1/4.2 is not
293 recommended. It is likely that this problem will be resolved
294 in future Python releases. As a work-around, it seems that
295 adding -fwrapv to the compiler options restores the earlier
298 Unix platforms: If your vendor still ships (and you still use) Berkeley DB
299 1.85 you will need to edit Modules/Setup to build the bsddb185
300 module and add a line to sitecustomize.py which makes it the
301 default. In Modules/Setup a line like
303 bsddb185 bsddbmodule.c
305 should work. (You may need to add -I, -L or -l flags to direct the
306 compiler and linker to your include files and libraries.)
308 XXX I think this next bit is out of date:
310 64-bit platforms: The modules audioop, imageop and rgbimg don't work.
311 The setup.py script disables them on 64-bit installations.
312 Don't try to enable them in the Modules/Setup file. They
313 contain code that is quite wordsize sensitive. (If you have a
316 Solaris: When using Sun's C compiler with threads, at least on Solaris
317 2.5.1, you need to add the "-mt" compiler option (the simplest
318 way is probably to specify the compiler with this option as
319 the "CC" environment variable when running the configure
322 When using GCC on Solaris, beware of binutils 2.13 or GCC
323 versions built using it. This mistakenly enables the
324 -zcombreloc option which creates broken shared libraries on
325 Solaris. binutils 2.12 works, and the binutils maintainers
326 are aware of the problem. Binutils 2.13.1 only partially
327 fixed things. It appears that 2.13.2 solves the problem
328 completely. This problem is known to occur with Solaris 2.7
329 and 2.8, but may also affect earlier and later versions of the
332 When the dynamic loader complains about errors finding shared
335 ld.so.1: ./python: fatal: libstdc++.so.5: open failed:
336 No such file or directory
338 you need to first make sure that the library is available on
339 your system. Then, you need to instruct the dynamic loader how
340 to find it. You can choose any of the following strategies:
342 1. When compiling Python, set LD_RUN_PATH to the directories
343 containing missing libraries.
344 2. When running Python, set LD_LIBRARY_PATH to these directories.
345 3. Use crle(8) to extend the search path of the loader.
346 4. Modify the installed GCC specs file, adding -R options into the
349 The complex object fails to compile on Solaris 10 with gcc 3.4 (at
350 least up to 3.4.3). To work around it, define Py_HUGE_VAL as
353 make CPPFLAGS='-D"Py_HUGE_VAL=HUGE_VAL()" -I. -I$(srcdir)/Include'
354 ./python setup.py CPPFLAGS='-D"Py_HUGE_VAL=HUGE_VAL()"'
356 Linux: A problem with threads and fork() was tracked down to a bug in
357 the pthreads code in glibc version 2.0.5; glibc version 2.0.7
358 solves the problem. This causes the popen2 test to fail;
359 problem and solution reported by Pablo Bleyer.
361 Red Hat Linux: Red Hat 9 built Python2.2 in UCS-4 mode and hacked
362 Tcl to support it. To compile Python2.3 with Tkinter, you will
363 need to pass --enable-unicode=ucs4 flag to ./configure.
365 There's an executable /usr/bin/python which is Python
366 1.5.2 on most older Red Hat installations; several key Red Hat tools
367 require this version. Python 2.1.x may be installed as
368 /usr/bin/python2. The Makefile installs Python as
369 /usr/local/bin/python, which may or may not take precedence
370 over /usr/bin/python, depending on how you have set up $PATH.
372 FreeBSD 3.x and probably platforms with NCurses that use libmytinfo or
373 similar: When using cursesmodule, the linking is not done in
374 the correct order with the defaults. Remove "-ltermcap" from
375 the readline entry in Setup, and use as curses entry: "curses
376 cursesmodule.c -lmytinfo -lncurses -ltermcap" - "mytinfo" (so
377 called on FreeBSD) should be the name of the auxiliary library
378 required on your platform. Normally, it would be linked
379 automatically, but not necessarily in the correct order.
381 BSDI: BSDI versions before 4.1 have known problems with threads,
382 which can cause strange errors in a number of modules (for
383 instance, the 'test_signal' test script will hang forever.)
384 Turning off threads (with --with-threads=no) or upgrading to
385 BSDI 4.1 solves this problem.
387 DEC Unix: Run configure with --with-dec-threads, or with
388 --with-threads=no if no threads are desired (threads are on by
389 default). When using GCC, it is possible to get an internal
390 compiler error if optimization is used. This was reported for
391 GCC 2.7.2.3 on selectmodule.c. Manually compile the affected
392 file without optimization to solve the problem.
394 DEC Ultrix: compile with GCC to avoid bugs in the native compiler,
395 and pass SHELL=/bin/sh5 to Make when installing.
397 AIX: A complete overhaul of the shared library support is now in
398 place. See Misc/AIX-NOTES for some notes on how it's done.
399 (The optimizer bug reported at this place in previous releases
400 has been worked around by a minimal code change.) If you get
401 errors about pthread_* functions, during compile or during
402 testing, try setting CC to a thread-safe (reentrant) compiler,
403 like "cc_r". For full C++ module support, set CC="xlC_r" (or
404 CC="xlC" without thread support).
406 AIX 5.3: To build a 64-bit version with IBM's compiler, I used the
409 export PATH=/usr/bin:/usr/vacpp/bin
410 ./configure --with-gcc="xlc_r -q64" --with-cxx="xlC_r -q64" \
411 --disable-ipv6 AR="ar -X64"
414 HP-UX: When using threading, you may have to add -D_REENTRANT to the
415 OPT variable in the top-level Makefile; reported by Pat Knight,
416 this seems to make a difference (at least for HP-UX 10.20)
417 even though pyconfig.h defines it. This seems unnecessary when
418 using HP/UX 11 and later - threading seems to work "out of the
421 HP-UX ia64: When building on the ia64 (Itanium) platform using HP's
422 compiler, some experience has shown that the compiler's
423 optimiser produces a completely broken version of python
424 (see http://www.python.org/sf/814976). To work around this,
425 edit the Makefile and remove -O from the OPT line.
427 To build a 64-bit executable on an Itanium 2 system using HP's
428 compiler, use these environment variables:
433 LDFLAGS="+DD64 -lxnet"
435 and call configure as:
437 ./configure --without-gcc
439 then *unset* the environment variables again before running
440 make. (At least one of these flags causes the build to fail
441 if it remains set.) You still have to edit the Makefile and
442 remove -O from the OPT line.
444 HP PA-RISC 2.0: A recent bug report (http://www.python.org/sf/546117)
445 suggests that the C compiler in this 64-bit system has bugs
446 in the optimizer that break Python. Compiling without
447 optimization solves the problems.
449 SCO: The following apply to SCO 3 only; Python builds out of the box
450 on SCO 5 (or so we've heard).
452 1) Everything works much better if you add -U__STDC__ to the
453 defs. This is because all the SCO header files are broken.
454 Anything that isn't mentioned in the C standard is
455 conditionally excluded when __STDC__ is defined.
457 2) Due to the U.S. export restrictions, SCO broke the crypt
458 stuff out into a separate library, libcrypt_i.a so the LIBS
461 LIBS=' -lsocket -lcrypt_i'
463 UnixWare: There are known bugs in the math library of the system, as well as
464 problems in the handling of threads (calling fork in one
465 thread may interrupt system calls in others). Therefore, test_math and
466 tests involving threads will fail until those problems are fixed.
468 QNX: Chris Herborth (chrish@qnx.com) writes:
469 configure works best if you use GNU bash; a port is available on
470 ftp.qnx.com in /usr/free. I used the following process to build,
471 test and install Python 1.5.x under QNX:
473 1) CONFIG_SHELL=/usr/local/bin/bash CC=cc RANLIB=: \
474 ./configure --verbose --without-gcc --with-libm=""
476 2) edit Modules/Setup to activate everything that makes sense for
477 your system... tested here at QNX with the following modules:
479 array, audioop, binascii, cPickle, cStringIO, cmath,
480 crypt, curses, errno, fcntl, gdbm, grp, imageop,
481 _locale, math, md5, new, operator, parser, pcre,
482 posix, pwd, readline, regex, reop, rgbimg, rotor,
483 select, signal, socket, soundex, strop, struct,
484 syslog, termios, time, timing, zlib, audioop, imageop, rgbimg
486 3) make SHELL=/usr/local/bin/bash
488 or, if you feel the need for speed:
490 make SHELL=/usr/local/bin/bash OPT="-5 -Oil+nrt"
492 4) make SHELL=/usr/local/bin/bash test
494 Using GNU readline 2.2 seems to behave strangely, but I
495 think that's a problem with my readline 2.2 port. :-\
497 5) make SHELL=/usr/local/bin/bash install
499 If you get SIGSEGVs while running Python (I haven't yet, but
500 I've only run small programs and the test cases), you're
501 probably running out of stack; the default 32k could be a
502 little tight. To increase the stack size, edit the Makefile
503 to read: LDFLAGS = -N 48k
505 BeOS: See Misc/BeOS-NOTES for notes about compiling/installing
506 Python on BeOS R3 or later. Note that only the PowerPC
507 platform is supported for R3; both PowerPC and x86 are
510 Cray T3E: Mark Hadfield (m.hadfield@niwa.co.nz) writes:
511 Python can be built satisfactorily on a Cray T3E but based on
512 my experience with the NIWA T3E (2002-05-22, version 2.2.1)
513 there are a few bugs and gotchas. For more information see a
514 thread on comp.lang.python in May 2002 entitled "Building
517 1) Use Cray's cc and not gcc. The latter was reported not to
518 work by Konrad Hinsen. It may work now, but it may not.
520 2) To set sys.platform to something sensible, pass the
521 following environment variable to the configure script:
525 2) Run configure with option "--enable-unicode=ucs4".
527 3) The Cray T3E does not support dynamic linking, so extension
528 modules have to be built by adding (or uncommenting) lines
529 in Modules/Setup. The minimum set of modules is
531 posix, new, _sre, unicodedata
533 On NIWA's vanilla T3E system the following have also been
534 included successfully:
536 _codecs, _locale, _socket, _symtable, _testcapi, _weakref
537 array, binascii, cmath, cPickle, crypt, cStringIO, dbm
538 errno, fcntl, grp, math, md5, operator, parser, pcre, pwd
539 regex, rotor, select, struct, strop, syslog, termios
540 time, timing, xreadlines
542 4) Once the python executable and library have been built, make
543 will execute setup.py, which will attempt to build remaining
544 extensions and link them dynamically. Each of these attempts
545 will fail but should not halt the make process. This is
548 5) Running "make test" uses a lot of resources and causes
549 problems on our system. You might want to try running tests
550 singly or in small groups.
552 SGI: SGI's standard "make" utility (/bin/make or /usr/bin/make)
553 does not check whether a command actually changed the file it
554 is supposed to build. This means that whenever you say "make"
555 it will redo the link step. The remedy is to use SGI's much
556 smarter "smake" utility (/usr/sbin/smake), or GNU make. If
557 you set the first line of the Makefile to #!/usr/sbin/smake
558 smake will be invoked by make (likewise for GNU make).
560 WARNING: There are bugs in the optimizer of some versions of
561 SGI's compilers that can cause bus errors or other strange
562 behavior, especially on numerical operations. To avoid this,
563 try building with "make OPT=".
565 OS/2: If you are running Warp3 or Warp4 and have IBM's VisualAge C/C++
566 compiler installed, just change into the pc\os2vacpp directory
567 and type NMAKE. Threading and sockets are supported by default
568 in the resulting binaries of PYTHON15.DLL and PYTHON.EXE.
570 Monterey (64-bit AIX): The current Monterey C compiler (Visual Age)
571 uses the OBJECT_MODE={32|64} environment variable to set the
572 compilation mode to either 32-bit or 64-bit (32-bit mode is
573 the default). Presumably you want 64-bit compilation mode for
574 this 64-bit OS. As a result you must first set OBJECT_MODE=64
575 in your environment before configuring (./configure) or
576 building (make) Python on Monterey.
578 Reliant UNIX: The thread support does not compile on Reliant UNIX, and
579 there is a (minor) problem in the configure script for that
580 platform as well. This should be resolved in time for a
583 MacOSX: The tests will crash on both 10.1 and 10.2 with SEGV in
584 test_re and test_sre due to the small default stack size. If
585 you set the stack size to 2048 before doing a "make test" the
586 failure can be avoided. If you're using the tcsh or csh shells,
587 use "limit stacksize 2048" and for the bash shell (the default
588 as of OSX 10.3), use "ulimit -s 2048".
590 On naked Darwin you may want to add the configure option
591 "--disable-toolbox-glue" to disable the glue code for the Carbon
592 interface modules. The modules themselves are currently only built
593 if you add the --enable-framework option, see below.
595 On a clean OSX /usr/local does not exist. Do a
596 "sudo mkdir -m 775 /usr/local"
597 before you do a make install. It is probably not a good idea to
598 do "sudo make install" which installs everything as superuser,
599 as this may later cause problems when installing distutils-based
602 Some people have reported problems building Python after using "fink"
603 to install additional unix software. Disabling fink (remove all
604 references to /sw from your .profile or .login) should solve this.
606 You may want to try the configure option "--enable-framework"
607 which installs Python as a framework. The location can be set
608 as argument to the --enable-framework option (default
609 /Library/Frameworks). A framework install is probably needed if you
610 want to use any Aqua-based GUI toolkit (whether Tkinter, wxPython,
611 Carbon, Cocoa or anything else).
613 You may also want to try the configure option "--enable-universalsdk"
614 which builds Python as a universal binary with support for the
615 i386 and PPC architectures. This requires Xcode 2.1 or later to build.
617 See Mac/OSX/README for more information on framework and
620 Cygwin: With recent (relative to the time of writing, 2001-12-19)
621 Cygwin installations, there are problems with the interaction
622 of dynamic linking and fork(). This manifests itself in build
623 failures during the execution of setup.py.
625 There are two workarounds that both enable Python (albeit
626 without threading support) to build and pass all tests on
627 NT/2000 (and most likely XP as well, though reports of testing
628 on XP would be appreciated).
632 (a) the band-aid fix is to link the _socket module statically
633 rather than dynamically (which is the default).
635 To do this, run "./configure --with-threads=no" including any
636 other options you need (--prefix, etc.). Then in Modules/Setup
640 #_socket socketmodule.c \
641 # -DUSE_SSL -I$(SSL)/include -I$(SSL)/include/openssl \
642 # -L$(SSL)/lib -lssl -lcrypto
644 and remove "local/" from the SSL variable. Finally, just run
647 (b) The "proper" fix is to rebase the Cygwin DLLs to prevent
648 base address conflicts. Details on how to do this can be
649 found in the following mail:
651 http://sources.redhat.com/ml/cygwin/2001-12/msg00894.html
653 It is hoped that a version of this solution will be
654 incorporated into the Cygwin distribution fairly soon.
656 Two additional problems:
658 (1) Threading support should still be disabled due to a known
659 bug in Cygwin pthreads that causes test_threadedtempfile to
662 (2) The _curses module does not build. This is a known
663 Cygwin ncurses problem that should be resolved the next time
664 that this package is released.
666 On older versions of Cygwin, test_poll may hang and test_strftime
669 The situation on 9X/Me is not accurately known at present.
670 Some time ago, there were reports that the following
671 regression tests failed:
677 Due to the test_select hang on 9X/Me, one should run the
678 regression test using the following:
680 make TESTOPTS='-l -x test_select' test
682 News regarding these platforms with more recent Cygwin
683 versions would be appreciated!
685 AtheOS: From Octavian Cerna <tavy at ylabs.com>:
689 Make sure you have shared versions of the libraries you
690 want to use with Python. You will have to compile them
691 yourself, or download precompiled packages.
693 Recommended libraries:
701 $ ./configure --prefix=/usr/python
704 Python is always built as a shared library, otherwise
705 dynamic loading would not work.
714 # pkgmanager -a /usr/python
719 - large file support: due to a stdio bug in glibc/libio,
720 access to large files may not work correctly. fseeko()
721 tries to seek to a negative offset. ftello() returns a
722 negative offset, it looks like a 32->64bit
723 sign-extension issue. The lowlevel functions (open,
725 - sockets: AF_UNIX is defined in the C library and in
726 Python, but not implemented in the system.
727 - select: poll is available in the C library, but does not
728 work (It does not return POLLNVAL for bad fds and
730 - posix: statvfs and fstatvfs always return ENOSYS.
732 - mmap: not yet implemented in AtheOS
733 - nis: broken (on an unconfigured system
734 yp_get_default_domain() returns junk instead of
736 - dl: dynamic loading doesn't work via dlopen()
737 - resource: getrimit and setrlimit are not yet
740 - if you are getting segmentation faults, you probably are
741 low on memory. AtheOS doesn't handle very well an
742 out-of-memory condition and simply SEGVs the process.
752 Configuring the bsddb and dbm modules
753 -------------------------------------
755 Beginning with Python version 2.3, the PyBsddb package
756 <http://pybsddb.sf.net/> was adopted into Python as the bsddb package,
757 exposing a set of package-level functions which provide
758 backwards-compatible behavior. Only versions 3.3 through 4.4 of
759 Sleepycat's libraries provide the necessary API, so older versions
760 aren't supported through this interface. The old bsddb module has
761 been retained as bsddb185, though it is not built by default. Users
762 wishing to use it will have to tweak Modules/Setup to build it. The
763 dbm module will still be built against the Sleepycat libraries if
764 other preferred alternatives (ndbm, gdbm) are not found.
766 Building the sqlite3 module
767 ---------------------------
769 To build the sqlite3 module, you'll need the sqlite3 or libsqlite3
770 packages installed, including the header files. Many modern operating
771 systems distribute the headers in a separate package to the library -
772 often it will be the same name as the main package, but with a -dev or
775 The version of pysqlite2 that's including in Python needs sqlite3 3.0.8
776 or later. setup.py attempts to check that it can find a correct version.
781 As of Python 2.0, threads are enabled by default. If you wish to
782 compile without threads, or if your thread support is broken, pass the
783 --with-threads=no switch to configure. Unfortunately, on some
784 platforms, additional compiler and/or linker options are required for
785 threads to work properly. Below is a table of those options,
786 collected by Bill Janssen. We would love to automate this process
787 more, but the information below is not enough to write a patch for the
788 configure.in file, so manual intervention is required. If you patch
789 the configure.in file and are confident that the patch works, please
790 send in the patch. (Don't bother patching the configure script itself
791 -- it is regenerated each time the configure.in file changes.)
793 Compiler switches for threads
794 .............................
796 The definition of _REENTRANT should be configured automatically, if
797 that does not work on your system, or if _REENTRANT is defined
798 incorrectly, please report that as a bug.
800 OS/Compiler/threads Switches for use with threads
801 (POSIX is draft 10, DCE is draft 4) compile & link
803 SunOS 5.{1-5}/{gcc,SunPro cc}/solaris -mt
804 SunOS 5.5/{gcc,SunPro cc}/POSIX (nothing)
805 DEC OSF/1 3.x/cc/DCE -threads
806 (butenhof@zko.dec.com)
807 Digital UNIX 4.x/cc/DCE -threads
808 (butenhof@zko.dec.com)
809 Digital UNIX 4.x/cc/POSIX -pthread
810 (butenhof@zko.dec.com)
811 AIX 4.1.4/cc_r/d7 (nothing)
813 AIX 4.1.4/cc_r4/DCE (nothing)
815 IRIX 6.2/cc/POSIX (nothing)
819 Linker (ld) libraries and flags for threads
820 ...........................................
822 OS/threads Libraries/switches for use with threads
824 SunOS 5.{1-5}/solaris -lthread
825 SunOS 5.5/POSIX -lpthread
826 DEC OSF/1 3.x/DCE -lpthreads -lmach -lc_r -lc
827 (butenhof@zko.dec.com)
828 Digital UNIX 4.x/DCE -lpthreads -lpthread -lmach -lexc -lc
829 (butenhof@zko.dec.com)
830 Digital UNIX 4.x/POSIX -lpthread -lmach -lexc -lc
831 (butenhof@zko.dec.com)
832 AIX 4.1.4/{draft7,DCE} (nothing)
834 IRIX 6.2/POSIX -lpthread
835 (jph@emilia.engr.sgi.com)
838 Building a shared libpython
839 ---------------------------
841 Starting with Python 2.3, the majority of the interpreter can be built
842 into a shared library, which can then be used by the interpreter
843 executable, and by applications embedding Python. To enable this feature,
844 configure with --enable-shared.
846 If you enable this feature, the same object files will be used to create
847 a static library. In particular, the static library will contain object
848 files using position-independent code (PIC) on platforms where PIC flags
849 are needed for the shared library.
852 Configuring additional built-in modules
853 ---------------------------------------
855 Starting with Python 2.1, the setup.py script at the top of the source
856 distribution attempts to detect which modules can be built and
857 automatically compiles them. Autodetection doesn't always work, so
858 you can still customize the configuration by editing the Modules/Setup
859 file; but this should be considered a last resort. The rest of this
860 section only applies if you decide to edit the Modules/Setup file.
861 You also need this to enable static linking of certain modules (which
862 is needed to enable profiling on some systems).
864 This file is initially copied from Setup.dist by the configure script;
865 if it does not exist yet, create it by copying Modules/Setup.dist
866 yourself (configure will never overwrite it). Never edit Setup.dist
867 -- always edit Setup or Setup.local (see below). Read the comments in
868 the file for information on what kind of edits are allowed. When you
869 have edited Setup in the Modules directory, the interpreter will
870 automatically be rebuilt the next time you run make (in the toplevel
873 Many useful modules can be built on any Unix system, but some optional
874 modules can't be reliably autodetected. Often the quickest way to
875 determine whether a particular module works or not is to see if it
876 will build: enable it in Setup, then if you get compilation or link
877 errors, disable it -- you're either missing support or need to adjust
878 the compilation and linking parameters for that module.
880 On SGI IRIX, there are modules that interface to many SGI specific
881 system libraries, e.g. the GL library and the audio hardware. These
882 modules will not be built by the setup.py script.
884 In addition to the file Setup, you can also edit the file Setup.local.
885 (the makesetup script processes both). You may find it more
886 convenient to edit Setup.local and leave Setup alone. Then, when
887 installing a new Python version, you can copy your old Setup.local
891 Setting the optimization/debugging options
892 ------------------------------------------
894 If you want or need to change the optimization/debugging options for
895 the C compiler, assign to the OPT variable on the toplevel make
896 command; e.g. "make OPT=-g" will build a debugging version of Python
897 on most platforms. The default is OPT=-O; a value for OPT in the
898 environment when the configure script is run overrides this default
899 (likewise for CC; and the initial value for LIBS is used as the base
900 set of libraries to link with).
902 When compiling with GCC, the default value of OPT will also include
903 the -Wall and -Wstrict-prototypes options.
905 Additional debugging code to help debug memory management problems can
906 be enabled by using the --with-pydebug option to the configure script.
908 For flags that change binary compatibility, use the EXTRA_CFLAGS
915 If you want C profiling turned on, the easiest way is to run configure
916 with the CC environment variable to the necessary compiler
917 invocation. For example, on Linux, this works for profiling using
920 CC="gcc -pg" ./configure
922 Note that on Linux, gprof apparently does not work for shared
923 libraries. The Makefile/Setup mechanism can be used to compile and
924 link most extension modules statically.
930 To test the interpreter, type "make test" in the top-level directory.
931 This runs the test set twice (once with no compiled files, once with
932 the compiled files left by the previous test run). The test set
933 produces some output. You can generally ignore the messages about
934 skipped tests due to optional features which can't be imported.
935 If a message is printed about a failed test or a traceback or core
936 dump is produced, something is wrong. On some Linux systems (those
937 that are not yet using glibc 6), test_strftime fails due to a
938 non-standard implementation of strftime() in the C library. Please
939 ignore this, or upgrade to glibc version 6.
941 IMPORTANT: If the tests fail and you decide to mail a bug report,
942 *don't* include the output of "make test". It is useless. Run the
943 failing test manually, as follows:
945 ./python ./Lib/test/test_whatever.py
947 (substituting the top of the source tree for '.' if you built in a
948 different directory). This runs the test in verbose mode.
954 To install the Python binary, library modules, shared library modules
955 (see below), include files, configuration files, and the manual page,
960 This will install all platform-independent files in subdirectories of
961 the directory given with the --prefix option to configure or to the
962 `prefix' Make variable (default /usr/local). All binary and other
963 platform-specific files will be installed in subdirectories if the
964 directory given by --exec-prefix or the `exec_prefix' Make variable
965 (defaults to the --prefix directory) is given.
967 If DESTDIR is set, it will be taken as the root directory of the
968 installation, and files will be installed into $(DESTDIR)$(prefix),
969 $(DESTDIR)$(exec_prefix), etc.
971 All subdirectories created will have Python's version number in their
972 name, e.g. the library modules are installed in
973 "/usr/local/lib/python<version>/" by default, where <version> is the
974 <major>.<minor> release number (e.g. "2.1"). The Python binary is
975 installed as "python<version>" and a hard link named "python" is
976 created. The only file not installed with a version number in its
977 name is the manual page, installed as "/usr/local/man/man1/python.1"
980 If you have a previous installation of Python that you don't
981 want to replace yet, use
985 This installs the same set of files as "make install" except it
986 doesn't create the hard link to "python<version>" named "python" and
987 it doesn't install the manual page at all.
989 The only thing you may have to install manually is the Python mode for
990 Emacs found in Misc/python-mode.el. (But then again, more recent
991 versions of Emacs may already have it.) Follow the instructions that
992 came with Emacs for installation of site-specific files.
994 On Mac OS X, if you have configured Python with --enable-framework, you
995 should use "make frameworkinstall" to do the installation. Note that this
996 installs the Python executable in a place that is not normally on your
997 PATH, you may want to set up a symlink in /usr/local/bin.
1000 Configuration options and variables
1001 -----------------------------------
1003 Some special cases are handled by passing options to the configure
1006 WARNING: if you rerun the configure script with different options, you
1007 must run "make clean" before rebuilding. Exceptions to this rule:
1008 after changing --prefix or --exec-prefix, all you need to do is remove
1011 --with(out)-gcc: The configure script uses gcc (the GNU C compiler) if
1012 it finds it. If you don't want this, or if this compiler is
1013 installed but broken on your platform, pass the option
1014 --without-gcc. You can also pass "CC=cc" (or whatever the
1015 name of the proper C compiler is) in the environment, but the
1016 advantage of using --without-gcc is that this option is
1017 remembered by the config.status script for its --recheck
1020 --prefix, --exec-prefix: If you want to install the binaries and the
1021 Python library somewhere else than in /usr/local/{bin,lib},
1022 you can pass the option --prefix=DIRECTORY; the interpreter
1023 binary will be installed as DIRECTORY/bin/python and the
1024 library files as DIRECTORY/lib/python/*. If you pass
1025 --exec-prefix=DIRECTORY (as well) this overrides the
1026 installation prefix for architecture-dependent files (like the
1027 interpreter binary). Note that --prefix=DIRECTORY also
1028 affects the default module search path (sys.path), when
1029 Modules/config.c is compiled. Passing make the option
1030 prefix=DIRECTORY (and/or exec_prefix=DIRECTORY) overrides the
1031 prefix set at configuration time; this may be more convenient
1032 than re-running the configure script if you change your mind
1033 about the install prefix.
1035 --with-readline: This option is no longer supported. GNU
1036 readline is automatically enabled by setup.py when present.
1038 --with-threads: On most Unix systems, you can now use multiple
1039 threads, and support for this is enabled by default. To
1040 disable this, pass --with-threads=no. If the library required
1041 for threads lives in a peculiar place, you can use
1042 --with-thread=DIRECTORY. IMPORTANT: run "make clean" after
1043 changing (either enabling or disabling) this option, or you
1044 will get link errors! Note: for DEC Unix use
1045 --with-dec-threads instead.
1047 --with-sgi-dl: On SGI IRIX 4, dynamic loading of extension modules is
1048 supported by the "dl" library by Jack Jansen, which is
1049 ftp'able from ftp://ftp.cwi.nl/pub/dynload/dl-1.6.tar.Z.
1050 This is enabled (after you've ftp'ed and compiled the dl
1051 library) by passing --with-sgi-dl=DIRECTORY where DIRECTORY
1052 is the absolute pathname of the dl library. (Don't bother on
1053 IRIX 5, it already has dynamic linking using SunOS style
1054 shared libraries.) THIS OPTION IS UNSUPPORTED.
1056 --with-dl-dld: Dynamic loading of modules is rumored to be supported
1057 on some other systems: VAX (Ultrix), Sun3 (SunOS 3.4), Sequent
1058 Symmetry (Dynix), and Atari ST. This is done using a
1059 combination of the GNU dynamic loading package
1060 (ftp://ftp.cwi.nl/pub/dynload/dl-dld-1.1.tar.Z) and an
1061 emulation of the SGI dl library mentioned above (the emulation
1063 ftp://ftp.cwi.nl/pub/dynload/dld-3.2.3.tar.Z). To
1064 enable this, ftp and compile both libraries, then call
1065 configure, passing it the option
1066 --with-dl-dld=DL_DIRECTORY,DLD_DIRECTORY where DL_DIRECTORY is
1067 the absolute pathname of the dl emulation library and
1068 DLD_DIRECTORY is the absolute pathname of the GNU dld library.
1069 (Don't bother on SunOS 4 or 5, they already have dynamic
1070 linking using shared libraries.) THIS OPTION IS UNSUPPORTED.
1072 --with-libm, --with-libc: It is possible to specify alternative
1073 versions for the Math library (default -lm) and the C library
1074 (default the empty string) using the options
1075 --with-libm=STRING and --with-libc=STRING, respectively. For
1076 example, if your system requires that you pass -lc_s to the C
1077 compiler to use the shared C library, you can pass
1078 --with-libc=-lc_s. These libraries are passed after all other
1079 libraries, the C library last.
1081 --with-libs='libs': Add 'libs' to the LIBS that the python interpreter
1084 --with-cxx-main=<compiler>: If you plan to use C++ extension modules,
1085 then -- on some platforms -- you need to compile python's main()
1086 function with the C++ compiler. With this option, make will use
1087 <compiler> to compile main() *and* to link the python executable.
1088 It is likely that the resulting executable depends on the C++
1089 runtime library of <compiler>. (The default is --without-cxx-main.)
1091 There are platforms that do not require you to build Python
1092 with a C++ compiler in order to use C++ extension modules.
1093 E.g., x86 Linux with ELF shared binaries and GCC 3.x, 4.x is such
1094 a platform. We recommend that you configure Python
1095 --without-cxx-main on those platforms because a mismatch
1096 between the C++ compiler version used to build Python and to
1097 build a C++ extension module is likely to cause a crash at
1100 The Python installation also stores the variable CXX that
1101 determines, e.g., the C++ compiler distutils calls by default
1102 to build C++ extensions. If you set CXX on the configure command
1103 line to any string of non-zero length, then configure won't
1104 change CXX. If you do not preset CXX but pass
1105 --with-cxx-main=<compiler>, then configure sets CXX=<compiler>.
1106 In all other cases, configure looks for a C++ compiler by
1107 some common names (c++, g++, gcc, CC, cxx, cc++, cl) and sets
1108 CXX to the first compiler it finds. If it does not find any
1109 C++ compiler, then it sets CXX="".
1111 Similarly, if you want to change the command used to link the
1112 python executable, then set LINKCC on the configure command line.
1115 --with-pydebug: Enable additional debugging code to help track down
1116 memory management problems. This allows printing a list of all
1117 live objects when the interpreter terminates.
1119 --with(out)-universal-newlines: enable reading of text files with
1120 foreign newline convention (default: enabled). In other words,
1121 any of \r, \n or \r\n is acceptable as end-of-line character.
1122 If enabled import and execfile will automatically accept any newline
1123 in files. Python code can open a file with open(file, 'U') to
1124 read it in universal newline mode. THIS OPTION IS UNSUPPORTED.
1126 --with-tsc: Profile using the Pentium timestamping counter (TSC).
1128 --with-system-ffi: Build the _ctypes extension module using an ffi
1129 library installed on the system.
1132 Building for multiple architectures (using the VPATH feature)
1133 -------------------------------------------------------------
1135 If your file system is shared between multiple architectures, it
1136 usually is not necessary to make copies of the sources for each
1137 architecture you want to support. If the make program supports the
1138 VPATH feature, you can create an empty build directory for each
1139 architecture, and in each directory run the configure script (on the
1140 appropriate machine with the appropriate options). This creates the
1141 necessary subdirectories and the Makefiles therein. The Makefiles
1142 contain a line VPATH=... which points to a directory containing the
1143 actual sources. (On SGI systems, use "smake -J1" instead of "make" if
1144 you use VPATH -- don't try gnumake.)
1146 For example, the following is all you need to build a minimal Python
1147 in /usr/tmp/python (assuming ~guido/src/python is the toplevel
1148 directory and you want to build in /usr/tmp/python):
1150 $ mkdir /usr/tmp/python
1151 $ cd /usr/tmp/python
1152 $ ~guido/src/python/configure
1158 Note that configure copies the original Setup file to the build
1159 directory if it finds no Setup file there. This means that you can
1160 edit the Setup file for each architecture independently. For this
1161 reason, subsequent changes to the original Setup file are not tracked
1162 automatically, as they might overwrite local changes. To force a copy
1163 of a changed original Setup file, delete the target Setup file. (The
1164 makesetup script supports multiple input files, so if you want to be
1165 fancy you can change the rules to create an empty Setup.local if it
1166 doesn't exist and run it with arguments $(srcdir)/Setup Setup.local;
1167 however this assumes that you only need to add modules.)
1170 Building on non-UNIX systems
1171 ----------------------------
1173 For Windows (2000/NT/ME/98/95), assuming you have MS VC++ 7.1, the
1174 project files are in PCbuild, the workspace is pcbuild.dsw. See
1175 PCbuild\readme.txt for detailed instructions.
1177 For other non-Unix Windows compilers, in particular MS VC++ 6.0 and
1178 for OS/2, enter the directory "PC" and read the file "readme.txt".
1180 For the Mac, a separate source distribution will be made available,
1181 for use with the CodeWarrior compiler. If you are interested in Mac
1182 development, join the PythonMac Special Interest Group
1183 (http://www.python.org/sigs/pythonmac-sig/, or send email to
1184 pythonmac-sig-request@python.org).
1186 Of course, there are also binary distributions available for these
1187 platforms -- see http://www.python.org/.
1189 To port Python to a new non-UNIX system, you will have to fake the
1190 effect of running the configure script manually (for Mac and PC, this
1191 has already been done for you). A good start is to copy the file
1192 pyconfig.h.in to pyconfig.h and edit the latter to reflect the actual
1193 configuration of your system. Most symbols must simply be defined as
1194 1 only if the corresponding feature is present and can be left alone
1195 otherwise; however the *_t type symbols must be defined as some
1196 variant of int if they need to be defined at all.
1198 For all platforms, it's important that the build arrange to define the
1199 preprocessor symbol NDEBUG on the compiler command line in a release
1200 build of Python (else assert() calls remain in the code, hurting
1201 release-build performance). The Unix, Windows and Mac builds already
1205 Miscellaneous issues
1206 ====================
1211 There's an excellent Emacs editing mode for Python code; see the file
1212 Misc/python-mode.el. Originally written by the famous Tim Peters, it
1213 is now maintained by the equally famous Barry Warsaw (it's no
1214 coincidence that they now both work on the same team). The latest
1215 version, along with various other contributed Python-related Emacs
1216 goodies, is online at http://www.python.org/emacs/python-mode. And
1217 if you are planning to edit the Python C code, please pick up the
1218 latest version of CC Mode http://www.python.org/emacs/cc-mode; it
1219 contains a "python" style used throughout most of the Python C source
1220 files. (Newer versions of Emacs or XEmacs may already come with the
1221 latest version of python-mode.)
1227 The setup.py script automatically configures this when it detects a
1228 usable Tcl/Tk installation. This requires Tcl/Tk version 8.0 or
1231 For more Tkinter information, see the Tkinter Resource page:
1232 http://www.python.org/topics/tkinter/
1234 There are demos in the Demo/tkinter directory.
1236 Note that there's a Python module called "Tkinter" (capital T) which
1237 lives in Lib/lib-tk/Tkinter.py, and a C module called "_tkinter"
1238 (lower case t and leading underscore) which lives in
1239 Modules/_tkinter.c. Demos and normal Tk applications import only the
1240 Python Tkinter module -- only the latter imports the C _tkinter
1241 module. In order to find the C _tkinter module, it must be compiled
1242 and linked into the Python interpreter -- the setup.py script does
1243 this. In order to find the Python Tkinter module, sys.path must be
1244 set correctly -- normal installation takes care of this.
1247 Distribution structure
1248 ----------------------
1250 Most subdirectories have their own README files. Most files have
1253 BeOS/ Files specific to the BeOS port
1254 Demo/ Demonstration scripts, modules and programs
1255 Doc/ Documentation sources (LaTeX)
1256 Grammar/ Input for the parser generator
1257 Include/ Public header files
1258 LICENSE Licensing information
1259 Lib/ Python library modules
1260 Mac/ Macintosh specific resources
1261 Makefile.pre.in Source from which config.status creates the Makefile.pre
1262 Misc/ Miscellaneous useful files
1263 Modules/ Implementation of most built-in modules
1264 Objects/ Implementation of most built-in object types
1265 PC/ Files specific to PC ports (DOS, Windows, OS/2)
1266 PCbuild/ Build directory for Microsoft Visual C++
1267 Parser/ The parser and tokenizer and their input handling
1268 Python/ The byte-compiler and interpreter
1269 README The file you're reading now
1270 Tools/ Some useful programs written in Python
1271 pyconfig.h.in Source from which pyconfig.h is created (GNU autoheader output)
1272 configure Configuration shell script (GNU autoconf output)
1273 configure.in Configuration specification (input for GNU autoconf)
1274 install-sh Shell script used to install files
1275 setup.py Python script used to build extension modules
1277 The following files will (may) be created in the toplevel directory by
1278 the configuration and build processes:
1280 Makefile Build rules
1281 Makefile.pre Build rules before running Modules/makesetup
1282 buildno Keeps track of the build number
1283 config.cache Cache of configuration variables
1284 pyconfig.h Configuration header
1285 config.log Log from last configure run
1286 config.status Status from last run of the configure script
1287 getbuildinfo.o Object file from Modules/getbuildinfo.c
1288 libpython<version>.a The library archive
1289 python The executable interpreter
1290 tags, TAGS Tags files for vi and Emacs
1297 --Guido van Rossum (home page: http://www.python.org/~guido/)