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(), isgeneratorfunction(),
11 isgenerator(), istraceback(), isframe(), iscode(), isbuiltin(),
12 isroutine() - check object types
13 getmembers() - get members of an object that satisfy a given condition
15 getfile(), getsourcefile(), getsource() - find an object's source code
16 getdoc(), getcomments() - get documentation on an object
17 getmodule() - determine the module that an object came from
18 getclasstree() - arrange classes so as to represent their hierarchy
20 getargspec(), getargvalues(), getcallargs() - get info about function arguments
21 formatargspec(), formatargvalues() - format an argument spec
22 getouterframes(), getinnerframes() - get info about frames
23 currentframe() - get the current stack frame
24 stack(), trace() - get info about frames on the stack or in a traceback
27 # This module is in the public domain. No warranties.
29 __author__ = 'Ka-Ping Yee <ping@lfw.org>'
30 __date__ = '1 Jan 2001'
41 from operator import attrgetter
42 from collections import namedtuple
44 # These constants are from Include/code.h.
45 CO_OPTIMIZED, CO_NEWLOCALS, CO_VARARGS, CO_VARKEYWORDS = 0x1, 0x2, 0x4, 0x8
46 CO_NESTED, CO_GENERATOR, CO_NOFREE = 0x10, 0x20, 0x40
47 # See Include/object.h
48 TPFLAGS_IS_ABSTRACT = 1 << 20
50 # ----------------------------------------------------------- type-checking
52 """Return true if the object is a module.
54 Module objects provide these attributes:
55 __doc__ documentation string
56 __file__ filename (missing for built-in modules)"""
57 return isinstance(object, types.ModuleType)
60 """Return true if the object is a class.
62 Class objects provide these attributes:
63 __doc__ documentation string
64 __module__ name of module in which this class was defined"""
65 return isinstance(object, (type, types.ClassType))
68 """Return true if the object is an instance method.
70 Instance method objects provide these attributes:
71 __doc__ documentation string
72 __name__ name with which this method was defined
73 im_class class object in which this method belongs
74 im_func function object containing implementation of method
75 im_self instance to which this method is bound, or None"""
76 return isinstance(object, types.MethodType)
78 def ismethoddescriptor(object):
79 """Return true if the object is a method descriptor.
81 But not if ismethod() or isclass() or isfunction() are true.
83 This is new in Python 2.2, and, for example, is true of int.__add__.
84 An object passing this test has a __get__ attribute but not a __set__
85 attribute, but beyond that the set of attributes varies. __name__ is
86 usually sensible, and __doc__ often is.
88 Methods implemented via descriptors that also pass one of the other
89 tests return false from the ismethoddescriptor() test, simply because
90 the other tests promise more -- you can, e.g., count on having the
91 im_func attribute (etc) when an object passes ismethod()."""
92 return (hasattr(object, "__get__")
93 and not hasattr(object, "__set__") # else it's a data descriptor
94 and not ismethod(object) # mutual exclusion
95 and not isfunction(object)
96 and not isclass(object))
98 def isdatadescriptor(object):
99 """Return true if the object is a data descriptor.
101 Data descriptors have both a __get__ and a __set__ attribute. Examples are
102 properties (defined in Python) and getsets and members (defined in C).
103 Typically, data descriptors will also have __name__ and __doc__ attributes
104 (properties, getsets, and members have both of these attributes), but this
105 is not guaranteed."""
106 return (hasattr(object, "__set__") and hasattr(object, "__get__"))
108 if hasattr(types, 'MemberDescriptorType'):
109 # CPython and equivalent
110 def ismemberdescriptor(object):
111 """Return true if the object is a member descriptor.
113 Member descriptors are specialized descriptors defined in extension
115 return isinstance(object, types.MemberDescriptorType)
117 # Other implementations
118 def ismemberdescriptor(object):
119 """Return true if the object is a member descriptor.
121 Member descriptors are specialized descriptors defined in extension
125 if hasattr(types, 'GetSetDescriptorType'):
126 # CPython and equivalent
127 def isgetsetdescriptor(object):
128 """Return true if the object is a getset descriptor.
130 getset descriptors are specialized descriptors defined in extension
132 return isinstance(object, types.GetSetDescriptorType)
134 # Other implementations
135 def isgetsetdescriptor(object):
136 """Return true if the object is a getset descriptor.
138 getset descriptors are specialized descriptors defined in extension
142 def isfunction(object):
143 """Return true if the object is a user-defined function.
145 Function objects provide these attributes:
146 __doc__ documentation string
147 __name__ name with which this function was defined
148 func_code code object containing compiled function bytecode
149 func_defaults tuple of any default values for arguments
150 func_doc (same as __doc__)
151 func_globals global namespace in which this function was defined
152 func_name (same as __name__)"""
153 return isinstance(object, types.FunctionType)
155 def isgeneratorfunction(object):
156 """Return true if the object is a user-defined generator function.
158 Generator function objects provides same attributes as functions.
160 See help(isfunction) for attributes listing."""
161 return bool((isfunction(object) or ismethod(object)) and
162 object.func_code.co_flags & CO_GENERATOR)
164 def isgenerator(object):
165 """Return true if the object is a generator.
167 Generator objects provide these attributes:
168 __iter__ defined to support interation over container
169 close raises a new GeneratorExit exception inside the
170 generator to terminate the iteration
172 gi_frame frame object or possibly None once the generator has
174 gi_running set to 1 when generator is executing, 0 otherwise
175 next return the next item from the container
176 send resumes the generator and "sends" a value that becomes
177 the result of the current yield-expression
178 throw used to raise an exception inside the generator"""
179 return isinstance(object, types.GeneratorType)
181 def istraceback(object):
182 """Return true if the object is a traceback.
184 Traceback objects provide these attributes:
185 tb_frame frame object at this level
186 tb_lasti index of last attempted instruction in bytecode
187 tb_lineno current line number in Python source code
188 tb_next next inner traceback object (called by this level)"""
189 return isinstance(object, types.TracebackType)
192 """Return true if the object is a frame object.
194 Frame objects provide these attributes:
195 f_back next outer frame object (this frame's caller)
196 f_builtins built-in namespace seen by this frame
197 f_code code object being executed in this frame
198 f_exc_traceback traceback if raised in this frame, or None
199 f_exc_type exception type if raised in this frame, or None
200 f_exc_value exception value if raised in this frame, or None
201 f_globals global namespace seen by this frame
202 f_lasti index of last attempted instruction in bytecode
203 f_lineno current line number in Python source code
204 f_locals local namespace seen by this frame
205 f_restricted 0 or 1 if frame is in restricted execution mode
206 f_trace tracing function for this frame, or None"""
207 return isinstance(object, types.FrameType)
210 """Return true if the object is a code object.
212 Code objects provide these attributes:
213 co_argcount number of arguments (not including * or ** args)
214 co_code string of raw compiled bytecode
215 co_consts tuple of constants used in the bytecode
216 co_filename name of file in which this code object was created
217 co_firstlineno number of first line in Python source code
218 co_flags bitmap: 1=optimized | 2=newlocals | 4=*arg | 8=**arg
219 co_lnotab encoded mapping of line numbers to bytecode indices
220 co_name name with which this code object was defined
221 co_names tuple of names of local variables
222 co_nlocals number of local variables
223 co_stacksize virtual machine stack space required
224 co_varnames tuple of names of arguments and local variables"""
225 return isinstance(object, types.CodeType)
227 def isbuiltin(object):
228 """Return true if the object is a built-in function or method.
230 Built-in functions and methods provide these attributes:
231 __doc__ documentation string
232 __name__ original name of this function or method
233 __self__ instance to which a method is bound, or None"""
234 return isinstance(object, types.BuiltinFunctionType)
236 def isroutine(object):
237 """Return true if the object is any kind of function or method."""
238 return (isbuiltin(object)
239 or isfunction(object)
241 or ismethoddescriptor(object))
243 def isabstract(object):
244 """Return true if the object is an abstract base class (ABC)."""
245 return bool(isinstance(object, type) and object.__flags__ & TPFLAGS_IS_ABSTRACT)
247 def getmembers(object, predicate=None):
248 """Return all members of an object as (name, value) pairs sorted by name.
249 Optionally, only return members that satisfy a given predicate."""
251 for key in dir(object):
253 value = getattr(object, key)
254 except AttributeError:
256 if not predicate or predicate(value):
257 results.append((key, value))
261 Attribute = namedtuple('Attribute', 'name kind defining_class object')
263 def classify_class_attrs(cls):
264 """Return list of attribute-descriptor tuples.
266 For each name in dir(cls), the return list contains a 4-tuple
269 0. The name (a string).
271 1. The kind of attribute this is, one of these strings:
272 'class method' created via classmethod()
273 'static method' created via staticmethod()
274 'property' created via property()
275 'method' any other flavor of method
278 2. The class which defined this attribute (a class).
280 3. The object as obtained directly from the defining class's
281 __dict__, not via getattr. This is especially important for
282 data attributes: C.data is just a data object, but
283 C.__dict__['data'] may be a data descriptor with additional
284 info, like a __doc__ string.
291 # Get the object associated with the name.
292 # Getting an obj from the __dict__ sometimes reveals more than
293 # using getattr. Static and class methods are dramatic examples.
294 if name in cls.__dict__:
295 obj = cls.__dict__[name]
297 obj = getattr(cls, name)
299 # Figure out where it was defined.
300 homecls = getattr(obj, "__objclass__", None)
304 if name in base.__dict__:
308 # Get the object again, in order to get it from the defining
309 # __dict__ instead of via getattr (if possible).
310 if homecls is not None and name in homecls.__dict__:
311 obj = homecls.__dict__[name]
313 # Also get the object via getattr.
314 obj_via_getattr = getattr(cls, name)
316 # Classify the object.
317 if isinstance(obj, staticmethod):
318 kind = "static method"
319 elif isinstance(obj, classmethod):
320 kind = "class method"
321 elif isinstance(obj, property):
323 elif (ismethod(obj_via_getattr) or
324 ismethoddescriptor(obj_via_getattr)):
329 result.append(Attribute(name, kind, homecls, obj))
333 # ----------------------------------------------------------- class helpers
334 def _searchbases(cls, accum):
335 # Simulate the "classic class" search order.
339 for base in cls.__bases__:
340 _searchbases(base, accum)
343 "Return tuple of base classes (including cls) in method resolution order."
344 if hasattr(cls, "__mro__"):
348 _searchbases(cls, result)
351 # -------------------------------------------------- source code extraction
352 def indentsize(line):
353 """Return the indent size, in spaces, at the start of a line of text."""
354 expline = string.expandtabs(line)
355 return len(expline) - len(string.lstrip(expline))
358 """Get the documentation string for an object.
360 All tabs are expanded to spaces. To clean up docstrings that are
361 indented to line up with blocks of code, any whitespace than can be
362 uniformly removed from the second line onwards is removed."""
365 except AttributeError:
367 if not isinstance(doc, types.StringTypes):
372 """Clean up indentation from docstrings.
374 Any whitespace that can be uniformly removed from the second line
375 onwards is removed."""
377 lines = string.split(string.expandtabs(doc), '\n')
381 # Find minimum indentation of any non-blank lines after first line.
383 for line in lines[1:]:
384 content = len(string.lstrip(line))
386 indent = len(line) - content
387 margin = min(margin, indent)
388 # Remove indentation.
390 lines[0] = lines[0].lstrip()
391 if margin < sys.maxint:
392 for i in range(1, len(lines)): lines[i] = lines[i][margin:]
393 # Remove any trailing or leading blank lines.
394 while lines and not lines[-1]:
396 while lines and not lines[0]:
398 return string.join(lines, '\n')
401 """Work out which source or compiled file an object was defined in."""
403 if hasattr(object, '__file__'):
404 return object.__file__
405 raise TypeError('{!r} is a built-in module'.format(object))
407 object = sys.modules.get(object.__module__)
408 if hasattr(object, '__file__'):
409 return object.__file__
410 raise TypeError('{!r} is a built-in class'.format(object))
412 object = object.im_func
413 if isfunction(object):
414 object = object.func_code
415 if istraceback(object):
416 object = object.tb_frame
418 object = object.f_code
420 return object.co_filename
421 raise TypeError('{!r} is not a module, class, method, '
422 'function, traceback, frame, or code object'.format(object))
424 ModuleInfo = namedtuple('ModuleInfo', 'name suffix mode module_type')
426 def getmoduleinfo(path):
427 """Get the module name, suffix, mode, and module type for a given file."""
428 filename = os.path.basename(path)
429 suffixes = map(lambda info:
430 (-len(info[0]), info[0], info[1], info[2]),
432 suffixes.sort() # try longest suffixes first, in case they overlap
433 for neglen, suffix, mode, mtype in suffixes:
434 if filename[neglen:] == suffix:
435 return ModuleInfo(filename[:neglen], suffix, mode, mtype)
437 def getmodulename(path):
438 """Return the module name for a given file, or None."""
439 info = getmoduleinfo(path)
440 if info: return info[0]
442 def getsourcefile(object):
443 """Return the filename that can be used to locate an object's source.
444 Return None if no way can be identified to get the source.
446 filename = getfile(object)
447 if string.lower(filename[-4:]) in ('.pyc', '.pyo'):
448 filename = filename[:-4] + '.py'
449 for suffix, mode, kind in imp.get_suffixes():
450 if 'b' in mode and string.lower(filename[-len(suffix):]) == suffix:
451 # Looks like a binary file. We want to only return a text file.
453 if os.path.exists(filename):
455 # only return a non-existent filename if the module has a PEP 302 loader
456 if hasattr(getmodule(object, filename), '__loader__'):
458 # or it is in the linecache
459 if filename in linecache.cache:
462 def getabsfile(object, _filename=None):
463 """Return an absolute path to the source or compiled file for an object.
465 The idea is for each object to have a unique origin, so this routine
466 normalizes the result as much as possible."""
467 if _filename is None:
468 _filename = getsourcefile(object) or getfile(object)
469 return os.path.normcase(os.path.abspath(_filename))
474 def getmodule(object, _filename=None):
475 """Return the module an object was defined in, or None if not found."""
478 if hasattr(object, '__module__'):
479 return sys.modules.get(object.__module__)
480 # Try the filename to modulename cache
481 if _filename is not None and _filename in modulesbyfile:
482 return sys.modules.get(modulesbyfile[_filename])
483 # Try the cache again with the absolute file name
485 file = getabsfile(object, _filename)
488 if file in modulesbyfile:
489 return sys.modules.get(modulesbyfile[file])
490 # Update the filename to module name cache and check yet again
491 # Copy sys.modules in order to cope with changes while iterating
492 for modname, module in sys.modules.items():
493 if ismodule(module) and hasattr(module, '__file__'):
495 if f == _filesbymodname.get(modname, None):
496 # Have already mapped this module, so skip it
498 _filesbymodname[modname] = f
499 f = getabsfile(module)
500 # Always map to the name the module knows itself by
501 modulesbyfile[f] = modulesbyfile[
502 os.path.realpath(f)] = module.__name__
503 if file in modulesbyfile:
504 return sys.modules.get(modulesbyfile[file])
505 # Check the main module
506 main = sys.modules['__main__']
507 if not hasattr(object, '__name__'):
509 if hasattr(main, object.__name__):
510 mainobject = getattr(main, object.__name__)
511 if mainobject is object:
514 builtin = sys.modules['__builtin__']
515 if hasattr(builtin, object.__name__):
516 builtinobject = getattr(builtin, object.__name__)
517 if builtinobject is object:
520 def findsource(object):
521 """Return the entire source file and starting line number for an object.
523 The argument may be a module, class, method, function, traceback, frame,
524 or code object. The source code is returned as a list of all the lines
525 in the file and the line number indexes a line in that list. An IOError
526 is raised if the source code cannot be retrieved."""
527 file = getsourcefile(object)
529 raise IOError('source code not available')
530 module = getmodule(object, file)
532 lines = linecache.getlines(file, module.__dict__)
534 lines = linecache.getlines(file)
536 raise IOError('could not get source code')
542 name = object.__name__
543 pat = re.compile(r'^(\s*)class\s*' + name + r'\b')
544 # make some effort to find the best matching class definition:
545 # use the one with the least indentation, which is the one
546 # that's most probably not inside a function definition.
548 for i in range(len(lines)):
549 match = pat.match(lines[i])
551 # if it's at toplevel, it's already the best one
552 if lines[i][0] == 'c':
554 # else add whitespace to candidate list
555 candidates.append((match.group(1), i))
557 # this will sort by whitespace, and by line number,
558 # less whitespace first
560 return lines, candidates[0][1]
562 raise IOError('could not find class definition')
565 object = object.im_func
566 if isfunction(object):
567 object = object.func_code
568 if istraceback(object):
569 object = object.tb_frame
571 object = object.f_code
573 if not hasattr(object, 'co_firstlineno'):
574 raise IOError('could not find function definition')
575 lnum = object.co_firstlineno - 1
576 pat = re.compile(r'^(\s*def\s)|(.*(?<!\w)lambda(:|\s))|^(\s*@)')
578 if pat.match(lines[lnum]): break
581 raise IOError('could not find code object')
583 def getcomments(object):
584 """Get lines of comments immediately preceding an object's source code.
586 Returns None when source can't be found.
589 lines, lnum = findsource(object)
590 except (IOError, TypeError):
594 # Look for a comment block at the top of the file.
596 if lines and lines[0][:2] == '#!': start = 1
597 while start < len(lines) and string.strip(lines[start]) in ('', '#'):
599 if start < len(lines) and lines[start][:1] == '#':
602 while end < len(lines) and lines[end][:1] == '#':
603 comments.append(string.expandtabs(lines[end]))
605 return string.join(comments, '')
607 # Look for a preceding block of comments at the same indentation.
609 indent = indentsize(lines[lnum])
611 if end >= 0 and string.lstrip(lines[end])[:1] == '#' and \
612 indentsize(lines[end]) == indent:
613 comments = [string.lstrip(string.expandtabs(lines[end]))]
616 comment = string.lstrip(string.expandtabs(lines[end]))
617 while comment[:1] == '#' and indentsize(lines[end]) == indent:
618 comments[:0] = [comment]
621 comment = string.lstrip(string.expandtabs(lines[end]))
622 while comments and string.strip(comments[0]) == '#':
624 while comments and string.strip(comments[-1]) == '#':
626 return string.join(comments, '')
628 class EndOfBlock(Exception): pass
631 """Provide a tokeneater() method to detect the end of a code block."""
634 self.islambda = False
636 self.passline = False
639 def tokeneater(self, type, token, srow_scol, erow_ecol, line):
640 srow, scol = srow_scol
641 erow, ecol = erow_ecol
643 # look for the first "def", "class" or "lambda"
644 if token in ("def", "class", "lambda"):
645 if token == "lambda":
648 self.passline = True # skip to the end of the line
649 elif type == tokenize.NEWLINE:
650 self.passline = False # stop skipping when a NEWLINE is seen
652 if self.islambda: # lambdas always end at the first NEWLINE
656 elif type == tokenize.INDENT:
657 self.indent = self.indent + 1
659 elif type == tokenize.DEDENT:
660 self.indent = self.indent - 1
661 # the end of matching indent/dedent pairs end a block
662 # (note that this only works for "def"/"class" blocks,
663 # not e.g. for "if: else:" or "try: finally:" blocks)
666 elif self.indent == 0 and type not in (tokenize.COMMENT, tokenize.NL):
667 # any other token on the same indentation level end the previous
668 # block as well, except the pseudo-tokens COMMENT and NL.
672 """Extract the block of code at the top of the given list of lines."""
673 blockfinder = BlockFinder()
675 tokenize.tokenize(iter(lines).next, blockfinder.tokeneater)
676 except (EndOfBlock, IndentationError):
678 return lines[:blockfinder.last]
680 def getsourcelines(object):
681 """Return a list of source lines and starting line number for an object.
683 The argument may be a module, class, method, function, traceback, frame,
684 or code object. The source code is returned as a list of the lines
685 corresponding to the object and the line number indicates where in the
686 original source file the first line of code was found. An IOError is
687 raised if the source code cannot be retrieved."""
688 lines, lnum = findsource(object)
690 if ismodule(object): return lines, 0
691 else: return getblock(lines[lnum:]), lnum + 1
693 def getsource(object):
694 """Return the text of the source code for an object.
696 The argument may be a module, class, method, function, traceback, frame,
697 or code object. The source code is returned as a single string. An
698 IOError is raised if the source code cannot be retrieved."""
699 lines, lnum = getsourcelines(object)
700 return string.join(lines, '')
702 # --------------------------------------------------- class tree extraction
703 def walktree(classes, children, parent):
704 """Recursive helper function for getclasstree()."""
706 classes.sort(key=attrgetter('__module__', '__name__'))
708 results.append((c, c.__bases__))
710 results.append(walktree(children[c], children, c))
713 def getclasstree(classes, unique=0):
714 """Arrange the given list of classes into a hierarchy of nested lists.
716 Where a nested list appears, it contains classes derived from the class
717 whose entry immediately precedes the list. Each entry is a 2-tuple
718 containing a class and a tuple of its base classes. If the 'unique'
719 argument is true, exactly one entry appears in the returned structure
720 for each class in the given list. Otherwise, classes using multiple
721 inheritance and their descendants will appear multiple times."""
726 for parent in c.__bases__:
727 if not parent in children:
728 children[parent] = []
729 children[parent].append(c)
730 if unique and parent in classes: break
733 for parent in children:
734 if parent not in classes:
736 return walktree(roots, children, None)
738 # ------------------------------------------------ argument list extraction
739 Arguments = namedtuple('Arguments', 'args varargs keywords')
742 """Get information about the arguments accepted by a code object.
744 Three things are returned: (args, varargs, varkw), where 'args' is
745 a list of argument names (possibly containing nested lists), and
746 'varargs' and 'varkw' are the names of the * and ** arguments or None."""
749 raise TypeError('{!r} is not a code object'.format(co))
751 nargs = co.co_argcount
752 names = co.co_varnames
753 args = list(names[:nargs])
756 # The following acrobatics are for anonymous (tuple) arguments.
757 for i in range(nargs):
758 if args[i][:1] in ('', '.'):
759 stack, remain, count = [], [], []
760 while step < len(co.co_code):
761 op = ord(co.co_code[step])
763 if op >= dis.HAVE_ARGUMENT:
764 opname = dis.opname[op]
765 value = ord(co.co_code[step]) + ord(co.co_code[step+1])*256
767 if opname in ('UNPACK_TUPLE', 'UNPACK_SEQUENCE'):
770 elif opname == 'STORE_FAST':
771 stack.append(names[value])
773 # Special case for sublists of length 1: def foo((bar))
774 # doesn't generate the UNPACK_TUPLE bytecode, so if
775 # `remain` is empty here, we have such a sublist.
777 stack[0] = [stack[0]]
780 remain[-1] = remain[-1] - 1
781 while remain[-1] == 0:
784 stack[-size:] = [stack[-size:]]
786 remain[-1] = remain[-1] - 1
791 if co.co_flags & CO_VARARGS:
792 varargs = co.co_varnames[nargs]
795 if co.co_flags & CO_VARKEYWORDS:
796 varkw = co.co_varnames[nargs]
797 return Arguments(args, varargs, varkw)
799 ArgSpec = namedtuple('ArgSpec', 'args varargs keywords defaults')
801 def getargspec(func):
802 """Get the names and default values of a function's arguments.
804 A tuple of four things is returned: (args, varargs, varkw, defaults).
805 'args' is a list of the argument names (it may contain nested lists).
806 'varargs' and 'varkw' are the names of the * and ** arguments or None.
807 'defaults' is an n-tuple of the default values of the last n arguments.
812 if not isfunction(func):
813 raise TypeError('{!r} is not a Python function'.format(func))
814 args, varargs, varkw = getargs(func.func_code)
815 return ArgSpec(args, varargs, varkw, func.func_defaults)
817 ArgInfo = namedtuple('ArgInfo', 'args varargs keywords locals')
819 def getargvalues(frame):
820 """Get information about arguments passed into a particular frame.
822 A tuple of four things is returned: (args, varargs, varkw, locals).
823 'args' is a list of the argument names (it may contain nested lists).
824 'varargs' and 'varkw' are the names of the * and ** arguments or None.
825 'locals' is the locals dictionary of the given frame."""
826 args, varargs, varkw = getargs(frame.f_code)
827 return ArgInfo(args, varargs, varkw, frame.f_locals)
831 return '(' + seq[0] + ',)'
833 return '(' + string.join(seq, ', ') + ')'
835 def strseq(object, convert, join=joinseq):
836 """Recursively walk a sequence, stringifying each element."""
837 if type(object) in (list, tuple):
838 return join(map(lambda o, c=convert, j=join: strseq(o, c, j), object))
840 return convert(object)
842 def formatargspec(args, varargs=None, varkw=None, defaults=None,
844 formatvarargs=lambda name: '*' + name,
845 formatvarkw=lambda name: '**' + name,
846 formatvalue=lambda value: '=' + repr(value),
848 """Format an argument spec from the 4 values returned by getargspec.
850 The first four arguments are (args, varargs, varkw, defaults). The
851 other four arguments are the corresponding optional formatting functions
852 that are called to turn names and values into strings. The ninth
853 argument is an optional function to format the sequence of arguments."""
856 firstdefault = len(args) - len(defaults)
857 for i, arg in enumerate(args):
858 spec = strseq(arg, formatarg, join)
859 if defaults and i >= firstdefault:
860 spec = spec + formatvalue(defaults[i - firstdefault])
862 if varargs is not None:
863 specs.append(formatvarargs(varargs))
864 if varkw is not None:
865 specs.append(formatvarkw(varkw))
866 return '(' + string.join(specs, ', ') + ')'
868 def formatargvalues(args, varargs, varkw, locals,
870 formatvarargs=lambda name: '*' + name,
871 formatvarkw=lambda name: '**' + name,
872 formatvalue=lambda value: '=' + repr(value),
874 """Format an argument spec from the 4 values returned by getargvalues.
876 The first four arguments are (args, varargs, varkw, locals). The
877 next four arguments are the corresponding optional formatting functions
878 that are called to turn names and values into strings. The ninth
879 argument is an optional function to format the sequence of arguments."""
880 def convert(name, locals=locals,
881 formatarg=formatarg, formatvalue=formatvalue):
882 return formatarg(name) + formatvalue(locals[name])
884 for i in range(len(args)):
885 specs.append(strseq(args[i], convert, join))
887 specs.append(formatvarargs(varargs) + formatvalue(locals[varargs]))
889 specs.append(formatvarkw(varkw) + formatvalue(locals[varkw]))
890 return '(' + string.join(specs, ', ') + ')'
892 def getcallargs(func, *positional, **named):
893 """Get the mapping of arguments to values.
895 A dict is returned, with keys the function argument names (including the
896 names of the * and ** arguments, if any), and values the respective bound
897 values from 'positional' and 'named'."""
898 args, varargs, varkw, defaults = getargspec(func)
899 f_name = func.__name__
902 # The following closures are basically because of tuple parameter unpacking.
903 assigned_tuple_params = []
904 def assign(arg, value):
905 if isinstance(arg, str):
906 arg2value[arg] = value
908 assigned_tuple_params.append(arg)
910 for i, subarg in enumerate(arg):
912 subvalue = next(value)
913 except StopIteration:
914 raise ValueError('need more than %d %s to unpack' %
915 (i, 'values' if i > 1 else 'value'))
916 assign(subarg,subvalue)
919 except StopIteration:
922 raise ValueError('too many values to unpack')
923 def is_assigned(arg):
924 if isinstance(arg,str):
925 return arg in arg2value
926 return arg in assigned_tuple_params
927 if ismethod(func) and func.im_self is not None:
928 # implicit 'self' (or 'cls' for classmethods) argument
929 positional = (func.im_self,) + positional
930 num_pos = len(positional)
931 num_total = num_pos + len(named)
933 num_defaults = len(defaults) if defaults else 0
934 for arg, value in zip(args, positional):
937 if num_pos > num_args:
938 assign(varargs, positional[-(num_pos-num_args):])
941 elif 0 < num_args < num_pos:
942 raise TypeError('%s() takes %s %d %s (%d given)' % (
943 f_name, 'at most' if defaults else 'exactly', num_args,
944 'arguments' if num_args > 1 else 'argument', num_total))
945 elif num_args == 0 and num_total:
946 raise TypeError('%s() takes no arguments (%d given)' %
949 if isinstance(arg, str) and arg in named:
951 raise TypeError("%s() got multiple values for keyword "
952 "argument '%s'" % (f_name, arg))
954 assign(arg, named.pop(arg))
955 if defaults: # fill in any missing values with the defaults
956 for arg, value in zip(args[-num_defaults:], defaults):
957 if not is_assigned(arg):
962 unexpected = next(iter(named))
963 if isinstance(unexpected, unicode):
964 unexpected = unexpected.encode(sys.getdefaultencoding(), 'replace')
965 raise TypeError("%s() got an unexpected keyword argument '%s'" %
966 (f_name, unexpected))
967 unassigned = num_args - len([arg for arg in args if is_assigned(arg)])
969 num_required = num_args - num_defaults
970 raise TypeError('%s() takes %s %d %s (%d given)' % (
971 f_name, 'at least' if defaults else 'exactly', num_required,
972 'arguments' if num_required > 1 else 'argument', num_total))
975 # -------------------------------------------------- stack frame extraction
977 Traceback = namedtuple('Traceback', 'filename lineno function code_context index')
979 def getframeinfo(frame, context=1):
980 """Get information about a frame or traceback object.
982 A tuple of five things is returned: the filename, the line number of
983 the current line, the function name, a list of lines of context from
984 the source code, and the index of the current line within that list.
985 The optional second argument specifies the number of lines of context
986 to return, which are centered around the current line."""
987 if istraceback(frame):
988 lineno = frame.tb_lineno
989 frame = frame.tb_frame
991 lineno = frame.f_lineno
992 if not isframe(frame):
993 raise TypeError('{!r} is not a frame or traceback object'.format(frame))
995 filename = getsourcefile(frame) or getfile(frame)
997 start = lineno - 1 - context//2
999 lines, lnum = findsource(frame)
1001 lines = index = None
1003 start = max(start, 1)
1004 start = max(0, min(start, len(lines) - context))
1005 lines = lines[start:start+context]
1006 index = lineno - 1 - start
1008 lines = index = None
1010 return Traceback(filename, lineno, frame.f_code.co_name, lines, index)
1012 def getlineno(frame):
1013 """Get the line number from a frame object, allowing for optimization."""
1014 # FrameType.f_lineno is now a descriptor that grovels co_lnotab
1015 return frame.f_lineno
1017 def getouterframes(frame, context=1):
1018 """Get a list of records for a frame and all higher (calling) frames.
1020 Each record contains a frame object, filename, line number, function
1021 name, a list of lines of context, and index within the context."""
1024 framelist.append((frame,) + getframeinfo(frame, context))
1025 frame = frame.f_back
1028 def getinnerframes(tb, context=1):
1029 """Get a list of records for a traceback's frame and all lower frames.
1031 Each record contains a frame object, filename, line number, function
1032 name, a list of lines of context, and index within the context."""
1035 framelist.append((tb.tb_frame,) + getframeinfo(tb, context))
1039 if hasattr(sys, '_getframe'):
1040 currentframe = sys._getframe
1042 currentframe = lambda _=None: None
1044 def stack(context=1):
1045 """Return a list of records for the stack above the caller's frame."""
1046 return getouterframes(sys._getframe(1), context)
1048 def trace(context=1):
1049 """Return a list of records for the stack below the current exception."""
1050 return getinnerframes(sys.exc_info()[2], context)