1 # -*- coding: iso-8859-1 -*-
2 """Get useful information from live Python objects.
4 This module encapsulates the interface provided by the internal special
5 attributes (func_*, co_*, im_*, tb_*, etc.) in a friendlier fashion.
6 It also provides some help for examining source code and class layout.
8 Here are some of the useful functions provided by this module:
10 ismodule(), isclass(), ismethod(), isfunction(), istraceback(),
11 isframe(), iscode(), isbuiltin(), isroutine() - check object types
12 getmembers() - get members of an object that satisfy a given condition
14 getfile(), getsourcefile(), getsource() - find an object's source code
15 getdoc(), getcomments() - get documentation on an object
16 getmodule() - determine the module that an object came from
17 getclasstree() - arrange classes so as to represent their hierarchy
19 getargspec(), getargvalues() - get info about function arguments
20 formatargspec(), formatargvalues() - format an argument spec
21 getouterframes(), getinnerframes() - get info about frames
22 currentframe() - get the current stack frame
23 stack(), trace() - get info about frames on the stack or in a traceback
26 # This module is in the public domain. No warranties.
28 __author__ = 'Ka-Ping Yee <ping@lfw.org>'
29 __date__ = '1 Jan 2001'
31 import sys, os, types, string, re, dis, imp, tokenize, linecache
32 from operator import attrgetter
34 # ----------------------------------------------------------- type-checking
36 """Return true if the object is a module.
38 Module objects provide these attributes:
39 __doc__ documentation string
40 __file__ filename (missing for built-in modules)"""
41 return isinstance(object, types.ModuleType)
44 """Return true if the object is a class.
46 Class objects provide these attributes:
47 __doc__ documentation string
48 __module__ name of module in which this class was defined"""
49 return isinstance(object, types.ClassType) or hasattr(object, '__bases__')
52 """Return true if the object is an instance method.
54 Instance method objects provide these attributes:
55 __doc__ documentation string
56 __name__ name with which this method was defined
57 im_class class object in which this method belongs
58 im_func function object containing implementation of method
59 im_self instance to which this method is bound, or None"""
60 return isinstance(object, types.MethodType)
62 def ismethoddescriptor(object):
63 """Return true if the object is a method descriptor.
65 But not if ismethod() or isclass() or isfunction() are true.
67 This is new in Python 2.2, and, for example, is true of int.__add__.
68 An object passing this test has a __get__ attribute but not a __set__
69 attribute, but beyond that the set of attributes varies. __name__ is
70 usually sensible, and __doc__ often is.
72 Methods implemented via descriptors that also pass one of the other
73 tests return false from the ismethoddescriptor() test, simply because
74 the other tests promise more -- you can, e.g., count on having the
75 im_func attribute (etc) when an object passes ismethod()."""
76 return (hasattr(object, "__get__")
77 and not hasattr(object, "__set__") # else it's a data descriptor
78 and not ismethod(object) # mutual exclusion
79 and not isfunction(object)
80 and not isclass(object))
82 def isdatadescriptor(object):
83 """Return true if the object is a data descriptor.
85 Data descriptors have both a __get__ and a __set__ attribute. Examples are
86 properties (defined in Python) and getsets and members (defined in C).
87 Typically, data descriptors will also have __name__ and __doc__ attributes
88 (properties, getsets, and members have both of these attributes), but this
90 return (hasattr(object, "__set__") and hasattr(object, "__get__"))
92 if hasattr(types, 'MemberDescriptorType'):
93 # CPython and equivalent
94 def ismemberdescriptor(object):
95 """Return true if the object is a member descriptor.
97 Member descriptors are specialized descriptors defined in extension
99 return isinstance(object, types.MemberDescriptorType)
101 # Other implementations
102 def ismemberdescriptor(object):
103 """Return true if the object is a member descriptor.
105 Member descriptors are specialized descriptors defined in extension
109 if hasattr(types, 'GetSetDescriptorType'):
110 # CPython and equivalent
111 def isgetsetdescriptor(object):
112 """Return true if the object is a getset descriptor.
114 getset descriptors are specialized descriptors defined in extension
116 return isinstance(object, types.GetSetDescriptorType)
118 # Other implementations
119 def isgetsetdescriptor(object):
120 """Return true if the object is a getset descriptor.
122 getset descriptors are specialized descriptors defined in extension
126 def isfunction(object):
127 """Return true if the object is a user-defined function.
129 Function objects provide these attributes:
130 __doc__ documentation string
131 __name__ name with which this function was defined
132 func_code code object containing compiled function bytecode
133 func_defaults tuple of any default values for arguments
134 func_doc (same as __doc__)
135 func_globals global namespace in which this function was defined
136 func_name (same as __name__)"""
137 return isinstance(object, types.FunctionType)
139 def istraceback(object):
140 """Return true if the object is a traceback.
142 Traceback objects provide these attributes:
143 tb_frame frame object at this level
144 tb_lasti index of last attempted instruction in bytecode
145 tb_lineno current line number in Python source code
146 tb_next next inner traceback object (called by this level)"""
147 return isinstance(object, types.TracebackType)
150 """Return true if the object is a frame object.
152 Frame objects provide these attributes:
153 f_back next outer frame object (this frame's caller)
154 f_builtins built-in namespace seen by this frame
155 f_code code object being executed in this frame
156 f_exc_traceback traceback if raised in this frame, or None
157 f_exc_type exception type if raised in this frame, or None
158 f_exc_value exception value if raised in this frame, or None
159 f_globals global namespace seen by this frame
160 f_lasti index of last attempted instruction in bytecode
161 f_lineno current line number in Python source code
162 f_locals local namespace seen by this frame
163 f_restricted 0 or 1 if frame is in restricted execution mode
164 f_trace tracing function for this frame, or None"""
165 return isinstance(object, types.FrameType)
168 """Return true if the object is a code object.
170 Code objects provide these attributes:
171 co_argcount number of arguments (not including * or ** args)
172 co_code string of raw compiled bytecode
173 co_consts tuple of constants used in the bytecode
174 co_filename name of file in which this code object was created
175 co_firstlineno number of first line in Python source code
176 co_flags bitmap: 1=optimized | 2=newlocals | 4=*arg | 8=**arg
177 co_lnotab encoded mapping of line numbers to bytecode indices
178 co_name name with which this code object was defined
179 co_names tuple of names of local variables
180 co_nlocals number of local variables
181 co_stacksize virtual machine stack space required
182 co_varnames tuple of names of arguments and local variables"""
183 return isinstance(object, types.CodeType)
185 def isbuiltin(object):
186 """Return true if the object is a built-in function or method.
188 Built-in functions and methods provide these attributes:
189 __doc__ documentation string
190 __name__ original name of this function or method
191 __self__ instance to which a method is bound, or None"""
192 return isinstance(object, types.BuiltinFunctionType)
194 def isroutine(object):
195 """Return true if the object is any kind of function or method."""
196 return (isbuiltin(object)
197 or isfunction(object)
199 or ismethoddescriptor(object))
201 def getmembers(object, predicate=None):
202 """Return all members of an object as (name, value) pairs sorted by name.
203 Optionally, only return members that satisfy a given predicate."""
205 for key in dir(object):
206 value = getattr(object, key)
207 if not predicate or predicate(value):
208 results.append((key, value))
212 def classify_class_attrs(cls):
213 """Return list of attribute-descriptor tuples.
215 For each name in dir(cls), the return list contains a 4-tuple
218 0. The name (a string).
220 1. The kind of attribute this is, one of these strings:
221 'class method' created via classmethod()
222 'static method' created via staticmethod()
223 'property' created via property()
224 'method' any other flavor of method
227 2. The class which defined this attribute (a class).
229 3. The object as obtained directly from the defining class's
230 __dict__, not via getattr. This is especially important for
231 data attributes: C.data is just a data object, but
232 C.__dict__['data'] may be a data descriptor with additional
233 info, like a __doc__ string.
240 # Get the object associated with the name.
241 # Getting an obj from the __dict__ sometimes reveals more than
242 # using getattr. Static and class methods are dramatic examples.
243 if name in cls.__dict__:
244 obj = cls.__dict__[name]
246 obj = getattr(cls, name)
248 # Figure out where it was defined.
249 homecls = getattr(obj, "__objclass__", None)
253 if name in base.__dict__:
257 # Get the object again, in order to get it from the defining
258 # __dict__ instead of via getattr (if possible).
259 if homecls is not None and name in homecls.__dict__:
260 obj = homecls.__dict__[name]
262 # Also get the object via getattr.
263 obj_via_getattr = getattr(cls, name)
265 # Classify the object.
266 if isinstance(obj, staticmethod):
267 kind = "static method"
268 elif isinstance(obj, classmethod):
269 kind = "class method"
270 elif isinstance(obj, property):
272 elif (ismethod(obj_via_getattr) or
273 ismethoddescriptor(obj_via_getattr)):
278 result.append((name, kind, homecls, obj))
282 # ----------------------------------------------------------- class helpers
283 def _searchbases(cls, accum):
284 # Simulate the "classic class" search order.
288 for base in cls.__bases__:
289 _searchbases(base, accum)
292 "Return tuple of base classes (including cls) in method resolution order."
293 if hasattr(cls, "__mro__"):
297 _searchbases(cls, result)
300 # -------------------------------------------------- source code extraction
301 def indentsize(line):
302 """Return the indent size, in spaces, at the start of a line of text."""
303 expline = string.expandtabs(line)
304 return len(expline) - len(string.lstrip(expline))
307 """Get the documentation string for an object.
309 All tabs are expanded to spaces. To clean up docstrings that are
310 indented to line up with blocks of code, any whitespace than can be
311 uniformly removed from the second line onwards is removed."""
314 except AttributeError:
316 if not isinstance(doc, types.StringTypes):
319 lines = string.split(string.expandtabs(doc), '\n')
323 # Find minimum indentation of any non-blank lines after first line.
325 for line in lines[1:]:
326 content = len(string.lstrip(line))
328 indent = len(line) - content
329 margin = min(margin, indent)
330 # Remove indentation.
332 lines[0] = lines[0].lstrip()
333 if margin < sys.maxint:
334 for i in range(1, len(lines)): lines[i] = lines[i][margin:]
335 # Remove any trailing or leading blank lines.
336 while lines and not lines[-1]:
338 while lines and not lines[0]:
340 return string.join(lines, '\n')
343 """Work out which source or compiled file an object was defined in."""
345 if hasattr(object, '__file__'):
346 return object.__file__
347 raise TypeError('arg is a built-in module')
349 object = sys.modules.get(object.__module__)
350 if hasattr(object, '__file__'):
351 return object.__file__
352 raise TypeError('arg is a built-in class')
354 object = object.im_func
355 if isfunction(object):
356 object = object.func_code
357 if istraceback(object):
358 object = object.tb_frame
360 object = object.f_code
362 return object.co_filename
363 raise TypeError('arg is not a module, class, method, '
364 'function, traceback, frame, or code object')
366 def getmoduleinfo(path):
367 """Get the module name, suffix, mode, and module type for a given file."""
368 filename = os.path.basename(path)
369 suffixes = map(lambda (suffix, mode, mtype):
370 (-len(suffix), suffix, mode, mtype), imp.get_suffixes())
371 suffixes.sort() # try longest suffixes first, in case they overlap
372 for neglen, suffix, mode, mtype in suffixes:
373 if filename[neglen:] == suffix:
374 return filename[:neglen], suffix, mode, mtype
376 def getmodulename(path):
377 """Return the module name for a given file, or None."""
378 info = getmoduleinfo(path)
379 if info: return info[0]
381 def getsourcefile(object):
382 """Return the Python source file an object was defined in, if it exists."""
383 filename = getfile(object)
384 if string.lower(filename[-4:]) in ('.pyc', '.pyo'):
385 filename = filename[:-4] + '.py'
386 for suffix, mode, kind in imp.get_suffixes():
387 if 'b' in mode and string.lower(filename[-len(suffix):]) == suffix:
388 # Looks like a binary file. We want to only return a text file.
390 if os.path.exists(filename):
392 # only return a non-existent filename if the module has a PEP 302 loader
393 if hasattr(getmodule(object, filename), '__loader__'):
396 def getabsfile(object, _filename=None):
397 """Return an absolute path to the source or compiled file for an object.
399 The idea is for each object to have a unique origin, so this routine
400 normalizes the result as much as possible."""
401 if _filename is None:
402 _filename = getsourcefile(object) or getfile(object)
403 return os.path.normcase(os.path.abspath(_filename))
408 def getmodule(object, _filename=None):
409 """Return the module an object was defined in, or None if not found."""
412 if hasattr(object, '__module__'):
413 return sys.modules.get(object.__module__)
414 # Try the filename to modulename cache
415 if _filename is not None and _filename in modulesbyfile:
416 return sys.modules.get(modulesbyfile[_filename])
417 # Try the cache again with the absolute file name
419 file = getabsfile(object, _filename)
422 if file in modulesbyfile:
423 return sys.modules.get(modulesbyfile[file])
424 # Update the filename to module name cache and check yet again
425 # Copy sys.modules in order to cope with changes while iterating
426 for modname, module in sys.modules.items():
427 if ismodule(module) and hasattr(module, '__file__'):
429 if f == _filesbymodname.get(modname, None):
430 # Have already mapped this module, so skip it
432 _filesbymodname[modname] = f
433 f = getabsfile(module)
434 # Always map to the name the module knows itself by
435 modulesbyfile[f] = modulesbyfile[
436 os.path.realpath(f)] = module.__name__
437 if file in modulesbyfile:
438 return sys.modules.get(modulesbyfile[file])
439 # Check the main module
440 main = sys.modules['__main__']
441 if not hasattr(object, '__name__'):
443 if hasattr(main, object.__name__):
444 mainobject = getattr(main, object.__name__)
445 if mainobject is object:
448 builtin = sys.modules['__builtin__']
449 if hasattr(builtin, object.__name__):
450 builtinobject = getattr(builtin, object.__name__)
451 if builtinobject is object:
454 def findsource(object):
455 """Return the entire source file and starting line number for an object.
457 The argument may be a module, class, method, function, traceback, frame,
458 or code object. The source code is returned as a list of all the lines
459 in the file and the line number indexes a line in that list. An IOError
460 is raised if the source code cannot be retrieved."""
461 file = getsourcefile(object) or getfile(object)
462 module = getmodule(object, file)
464 lines = linecache.getlines(file, module.__dict__)
466 lines = linecache.getlines(file)
468 raise IOError('could not get source code')
474 name = object.__name__
475 pat = re.compile(r'^(\s*)class\s*' + name + r'\b')
476 # make some effort to find the best matching class definition:
477 # use the one with the least indentation, which is the one
478 # that's most probably not inside a function definition.
480 for i in range(len(lines)):
481 match = pat.match(lines[i])
483 # if it's at toplevel, it's already the best one
484 if lines[i][0] == 'c':
486 # else add whitespace to candidate list
487 candidates.append((match.group(1), i))
489 # this will sort by whitespace, and by line number,
490 # less whitespace first
492 return lines, candidates[0][1]
494 raise IOError('could not find class definition')
497 object = object.im_func
498 if isfunction(object):
499 object = object.func_code
500 if istraceback(object):
501 object = object.tb_frame
503 object = object.f_code
505 if not hasattr(object, 'co_firstlineno'):
506 raise IOError('could not find function definition')
507 lnum = object.co_firstlineno - 1
508 pat = re.compile(r'^(\s*def\s)|(.*(?<!\w)lambda(:|\s))|^(\s*@)')
510 if pat.match(lines[lnum]): break
513 raise IOError('could not find code object')
515 def getcomments(object):
516 """Get lines of comments immediately preceding an object's source code.
518 Returns None when source can't be found.
521 lines, lnum = findsource(object)
522 except (IOError, TypeError):
526 # Look for a comment block at the top of the file.
528 if lines and lines[0][:2] == '#!': start = 1
529 while start < len(lines) and string.strip(lines[start]) in ('', '#'):
531 if start < len(lines) and lines[start][:1] == '#':
534 while end < len(lines) and lines[end][:1] == '#':
535 comments.append(string.expandtabs(lines[end]))
537 return string.join(comments, '')
539 # Look for a preceding block of comments at the same indentation.
541 indent = indentsize(lines[lnum])
543 if end >= 0 and string.lstrip(lines[end])[:1] == '#' and \
544 indentsize(lines[end]) == indent:
545 comments = [string.lstrip(string.expandtabs(lines[end]))]
548 comment = string.lstrip(string.expandtabs(lines[end]))
549 while comment[:1] == '#' and indentsize(lines[end]) == indent:
550 comments[:0] = [comment]
553 comment = string.lstrip(string.expandtabs(lines[end]))
554 while comments and string.strip(comments[0]) == '#':
556 while comments and string.strip(comments[-1]) == '#':
558 return string.join(comments, '')
560 class EndOfBlock(Exception): pass
563 """Provide a tokeneater() method to detect the end of a code block."""
566 self.islambda = False
568 self.passline = False
571 def tokeneater(self, type, token, (srow, scol), (erow, ecol), line):
573 # look for the first "def", "class" or "lambda"
574 if token in ("def", "class", "lambda"):
575 if token == "lambda":
578 self.passline = True # skip to the end of the line
579 elif type == tokenize.NEWLINE:
580 self.passline = False # stop skipping when a NEWLINE is seen
582 if self.islambda: # lambdas always end at the first NEWLINE
586 elif type == tokenize.INDENT:
587 self.indent = self.indent + 1
589 elif type == tokenize.DEDENT:
590 self.indent = self.indent - 1
591 # the end of matching indent/dedent pairs end a block
592 # (note that this only works for "def"/"class" blocks,
593 # not e.g. for "if: else:" or "try: finally:" blocks)
596 elif self.indent == 0 and type not in (tokenize.COMMENT, tokenize.NL):
597 # any other token on the same indentation level end the previous
598 # block as well, except the pseudo-tokens COMMENT and NL.
602 """Extract the block of code at the top of the given list of lines."""
603 blockfinder = BlockFinder()
605 tokenize.tokenize(iter(lines).next, blockfinder.tokeneater)
606 except (EndOfBlock, IndentationError):
608 return lines[:blockfinder.last]
610 def getsourcelines(object):
611 """Return a list of source lines and starting line number for an object.
613 The argument may be a module, class, method, function, traceback, frame,
614 or code object. The source code is returned as a list of the lines
615 corresponding to the object and the line number indicates where in the
616 original source file the first line of code was found. An IOError is
617 raised if the source code cannot be retrieved."""
618 lines, lnum = findsource(object)
620 if ismodule(object): return lines, 0
621 else: return getblock(lines[lnum:]), lnum + 1
623 def getsource(object):
624 """Return the text of the source code for an object.
626 The argument may be a module, class, method, function, traceback, frame,
627 or code object. The source code is returned as a single string. An
628 IOError is raised if the source code cannot be retrieved."""
629 lines, lnum = getsourcelines(object)
630 return string.join(lines, '')
632 # --------------------------------------------------- class tree extraction
633 def walktree(classes, children, parent):
634 """Recursive helper function for getclasstree()."""
636 classes.sort(key=attrgetter('__module__', '__name__'))
638 results.append((c, c.__bases__))
640 results.append(walktree(children[c], children, c))
643 def getclasstree(classes, unique=0):
644 """Arrange the given list of classes into a hierarchy of nested lists.
646 Where a nested list appears, it contains classes derived from the class
647 whose entry immediately precedes the list. Each entry is a 2-tuple
648 containing a class and a tuple of its base classes. If the 'unique'
649 argument is true, exactly one entry appears in the returned structure
650 for each class in the given list. Otherwise, classes using multiple
651 inheritance and their descendants will appear multiple times."""
656 for parent in c.__bases__:
657 if not parent in children:
658 children[parent] = []
659 children[parent].append(c)
660 if unique and parent in classes: break
663 for parent in children:
664 if parent not in classes:
666 return walktree(roots, children, None)
668 # ------------------------------------------------ argument list extraction
669 # These constants are from Python's compile.h.
670 CO_OPTIMIZED, CO_NEWLOCALS, CO_VARARGS, CO_VARKEYWORDS = 1, 2, 4, 8
673 """Get information about the arguments accepted by a code object.
675 Three things are returned: (args, varargs, varkw), where 'args' is
676 a list of argument names (possibly containing nested lists), and
677 'varargs' and 'varkw' are the names of the * and ** arguments or None."""
680 raise TypeError('arg is not a code object')
683 nargs = co.co_argcount
684 names = co.co_varnames
685 args = list(names[:nargs])
688 # The following acrobatics are for anonymous (tuple) arguments.
689 for i in range(nargs):
690 if args[i][:1] in ('', '.'):
691 stack, remain, count = [], [], []
692 while step < len(code):
695 if op >= dis.HAVE_ARGUMENT:
696 opname = dis.opname[op]
697 value = ord(code[step]) + ord(code[step+1])*256
699 if opname in ('UNPACK_TUPLE', 'UNPACK_SEQUENCE'):
702 elif opname == 'STORE_FAST':
703 stack.append(names[value])
705 # Special case for sublists of length 1: def foo((bar))
706 # doesn't generate the UNPACK_TUPLE bytecode, so if
707 # `remain` is empty here, we have such a sublist.
709 stack[0] = [stack[0]]
712 remain[-1] = remain[-1] - 1
713 while remain[-1] == 0:
716 stack[-size:] = [stack[-size:]]
718 remain[-1] = remain[-1] - 1
723 if co.co_flags & CO_VARARGS:
724 varargs = co.co_varnames[nargs]
727 if co.co_flags & CO_VARKEYWORDS:
728 varkw = co.co_varnames[nargs]
729 return args, varargs, varkw
731 def getargspec(func):
732 """Get the names and default values of a function's arguments.
734 A tuple of four things is returned: (args, varargs, varkw, defaults).
735 'args' is a list of the argument names (it may contain nested lists).
736 'varargs' and 'varkw' are the names of the * and ** arguments or None.
737 'defaults' is an n-tuple of the default values of the last n arguments.
742 if not isfunction(func):
743 raise TypeError('arg is not a Python function')
744 args, varargs, varkw = getargs(func.func_code)
745 return args, varargs, varkw, func.func_defaults
747 def getargvalues(frame):
748 """Get information about arguments passed into a particular frame.
750 A tuple of four things is returned: (args, varargs, varkw, locals).
751 'args' is a list of the argument names (it may contain nested lists).
752 'varargs' and 'varkw' are the names of the * and ** arguments or None.
753 'locals' is the locals dictionary of the given frame."""
754 args, varargs, varkw = getargs(frame.f_code)
755 return args, varargs, varkw, frame.f_locals
759 return '(' + seq[0] + ',)'
761 return '(' + string.join(seq, ', ') + ')'
763 def strseq(object, convert, join=joinseq):
764 """Recursively walk a sequence, stringifying each element."""
765 if type(object) in (list, tuple):
766 return join(map(lambda o, c=convert, j=join: strseq(o, c, j), object))
768 return convert(object)
770 def formatargspec(args, varargs=None, varkw=None, defaults=None,
772 formatvarargs=lambda name: '*' + name,
773 formatvarkw=lambda name: '**' + name,
774 formatvalue=lambda value: '=' + repr(value),
776 """Format an argument spec from the 4 values returned by getargspec.
778 The first four arguments are (args, varargs, varkw, defaults). The
779 other four arguments are the corresponding optional formatting functions
780 that are called to turn names and values into strings. The ninth
781 argument is an optional function to format the sequence of arguments."""
784 firstdefault = len(args) - len(defaults)
785 for i in range(len(args)):
786 spec = strseq(args[i], formatarg, join)
787 if defaults and i >= firstdefault:
788 spec = spec + formatvalue(defaults[i - firstdefault])
790 if varargs is not None:
791 specs.append(formatvarargs(varargs))
792 if varkw is not None:
793 specs.append(formatvarkw(varkw))
794 return '(' + string.join(specs, ', ') + ')'
796 def formatargvalues(args, varargs, varkw, locals,
798 formatvarargs=lambda name: '*' + name,
799 formatvarkw=lambda name: '**' + name,
800 formatvalue=lambda value: '=' + repr(value),
802 """Format an argument spec from the 4 values returned by getargvalues.
804 The first four arguments are (args, varargs, varkw, locals). The
805 next four arguments are the corresponding optional formatting functions
806 that are called to turn names and values into strings. The ninth
807 argument is an optional function to format the sequence of arguments."""
808 def convert(name, locals=locals,
809 formatarg=formatarg, formatvalue=formatvalue):
810 return formatarg(name) + formatvalue(locals[name])
812 for i in range(len(args)):
813 specs.append(strseq(args[i], convert, join))
815 specs.append(formatvarargs(varargs) + formatvalue(locals[varargs]))
817 specs.append(formatvarkw(varkw) + formatvalue(locals[varkw]))
818 return '(' + string.join(specs, ', ') + ')'
820 # -------------------------------------------------- stack frame extraction
821 def getframeinfo(frame, context=1):
822 """Get information about a frame or traceback object.
824 A tuple of five things is returned: the filename, the line number of
825 the current line, the function name, a list of lines of context from
826 the source code, and the index of the current line within that list.
827 The optional second argument specifies the number of lines of context
828 to return, which are centered around the current line."""
829 if istraceback(frame):
830 lineno = frame.tb_lineno
831 frame = frame.tb_frame
833 lineno = frame.f_lineno
834 if not isframe(frame):
835 raise TypeError('arg is not a frame or traceback object')
837 filename = getsourcefile(frame) or getfile(frame)
839 start = lineno - 1 - context//2
841 lines, lnum = findsource(frame)
845 start = max(start, 1)
846 start = max(0, min(start, len(lines) - context))
847 lines = lines[start:start+context]
848 index = lineno - 1 - start
852 return (filename, lineno, frame.f_code.co_name, lines, index)
854 def getlineno(frame):
855 """Get the line number from a frame object, allowing for optimization."""
856 # FrameType.f_lineno is now a descriptor that grovels co_lnotab
857 return frame.f_lineno
859 def getouterframes(frame, context=1):
860 """Get a list of records for a frame and all higher (calling) frames.
862 Each record contains a frame object, filename, line number, function
863 name, a list of lines of context, and index within the context."""
866 framelist.append((frame,) + getframeinfo(frame, context))
870 def getinnerframes(tb, context=1):
871 """Get a list of records for a traceback's frame and all lower frames.
873 Each record contains a frame object, filename, line number, function
874 name, a list of lines of context, and index within the context."""
877 framelist.append((tb.tb_frame,) + getframeinfo(tb, context))
881 currentframe = sys._getframe
883 def stack(context=1):
884 """Return a list of records for the stack above the caller's frame."""
885 return getouterframes(sys._getframe(1), context)
887 def trace(context=1):
888 """Return a list of records for the stack below the current exception."""
889 return getinnerframes(sys.exc_info()[2], context)