Editing: inspect.py
# -*- coding: iso-8859-1 -*- """Get useful information from live Python objects. This module encapsulates the interface provided by the internal special attributes (func_*, co_*, im_*, tb_*, etc.) in a friendlier fashion. It also provides some help for examining source code and class layout. Here are some of the useful functions provided by this module: ismodule(), isclass(), ismethod(), isfunction(), isgeneratorfunction(), isgenerator(), istraceback(), isframe(), iscode(), isbuiltin(), isroutine() - check object types getmembers() - get members of an object that satisfy a given condition getfile(), getsourcefile(), getsource() - find an object's source code getdoc(), getcomments() - get documentation on an object getmodule() - determine the module that an object came from getclasstree() - arrange classes so as to represent their hierarchy getargspec(), getargvalues(), getcallargs() - get info about function arguments formatargspec(), formatargvalues() - format an argument spec getouterframes(), getinnerframes() - get info about frames currentframe() - get the current stack frame stack(), trace() - get info about frames on the stack or in a traceback """ # This module is in the public domain. No warranties. __author__ = 'Ka-Ping Yee <ping@lfw.org>' __date__ = '1 Jan 2001' import sys import os import types import string import re import dis import imp import tokenize import linecache from operator import attrgetter from collections import namedtuple # These constants are from Include/code.h. CO_OPTIMIZED, CO_NEWLOCALS, CO_VARARGS, CO_VARKEYWORDS = 0x1, 0x2, 0x4, 0x8 CO_NESTED, CO_GENERATOR, CO_NOFREE = 0x10, 0x20, 0x40 # See Include/object.h TPFLAGS_IS_ABSTRACT = 1 << 20 # ----------------------------------------------------------- type-checking def ismodule(object): """Return true if the object is a module. Module objects provide these attributes: __doc__ documentation string __file__ filename (missing for built-in modules)""" return isinstance(object, types.ModuleType) def isclass(object): """Return true if the object is a class. Class objects provide these attributes: __doc__ documentation string __module__ name of module in which this class was defined""" return isinstance(object, (type, types.ClassType)) def ismethod(object): """Return true if the object is an instance method. Instance method objects provide these attributes: __doc__ documentation string __name__ name with which this method was defined im_class class object in which this method belongs im_func function object containing implementation of method im_self instance to which this method is bound, or None""" return isinstance(object, types.MethodType) def ismethoddescriptor(object): """Return true if the object is a method descriptor. But not if ismethod() or isclass() or isfunction() are true. This is new in Python 2.2, and, for example, is true of int.__add__. An object passing this test has a __get__ attribute but not a __set__ attribute, but beyond that the set of attributes varies. __name__ is usually sensible, and __doc__ often is. Methods implemented via descriptors that also pass one of the other tests return false from the ismethoddescriptor() test, simply because the other tests promise more -- you can, e.g., count on having the im_func attribute (etc) when an object passes ismethod().""" return (hasattr(object, "__get__") and not hasattr(object, "__set__") # else it's a data descriptor and not ismethod(object) # mutual exclusion and not isfunction(object) and not isclass(object)) def isdatadescriptor(object): """Return true if the object is a data descriptor. Data descriptors have both a __get__ and a __set__ attribute. Examples are properties (defined in Python) and getsets and members (defined in C). Typically, data descriptors will also have __name__ and __doc__ attributes (properties, getsets, and members have both of these attributes), but this is not guaranteed.""" return (hasattr(object, "__set__") and hasattr(object, "__get__")) if hasattr(types, 'MemberDescriptorType'): # CPython and equivalent def ismemberdescriptor(object): """Return true if the object is a member descriptor. Member descriptors are specialized descriptors defined in extension modules.""" return isinstance(object, types.MemberDescriptorType) else: # Other implementations def ismemberdescriptor(object): """Return true if the object is a member descriptor. Member descriptors are specialized descriptors defined in extension modules.""" return False if hasattr(types, 'GetSetDescriptorType'): # CPython and equivalent def isgetsetdescriptor(object): """Return true if the object is a getset descriptor. getset descriptors are specialized descriptors defined in extension modules.""" return isinstance(object, types.GetSetDescriptorType) else: # Other implementations def isgetsetdescriptor(object): """Return true if the object is a getset descriptor. getset descriptors are specialized descriptors defined in extension modules.""" return False def isfunction(object): """Return true if the object is a user-defined function. Function objects provide these attributes: __doc__ documentation string __name__ name with which this function was defined func_code code object containing compiled function bytecode func_defaults tuple of any default values for arguments func_doc (same as __doc__) func_globals global namespace in which this function was defined func_name (same as __name__)""" return isinstance(object, types.FunctionType) def isgeneratorfunction(object): """Return true if the object is a user-defined generator function. Generator function objects provide the same attributes as functions. See help(isfunction) for a list of attributes.""" return bool((isfunction(object) or ismethod(object)) and object.func_code.co_flags & CO_GENERATOR) def isgenerator(object): """Return true if the object is a generator. Generator objects provide these attributes: __iter__ defined to support iteration over container close raises a new GeneratorExit exception inside the generator to terminate the iteration gi_code code object gi_frame frame object or possibly None once the generator has been exhausted gi_running set to 1 when generator is executing, 0 otherwise next return the next item from the container send resumes the generator and "sends" a value that becomes the result of the current yield-expression throw used to raise an exception inside the generator""" return isinstance(object, types.GeneratorType) def istraceback(object): """Return true if the object is a traceback. Traceback objects provide these attributes: tb_frame frame object at this level tb_lasti index of last attempted instruction in bytecode tb_lineno current line number in Python source code tb_next next inner traceback object (called by this level)""" return isinstance(object, types.TracebackType) def isframe(object): """Return true if the object is a frame object. Frame objects provide these attributes: f_back next outer frame object (this frame's caller) f_builtins built-in namespace seen by this frame f_code code object being executed in this frame f_exc_traceback traceback if raised in this frame, or None f_exc_type exception type if raised in this frame, or None f_exc_value exception value if raised in this frame, or None f_globals global namespace seen by this frame f_lasti index of last attempted instruction in bytecode f_lineno current line number in Python source code f_locals local namespace seen by this frame f_restricted 0 or 1 if frame is in restricted execution mode f_trace tracing function for this frame, or None""" return isinstance(object, types.FrameType) def iscode(object): """Return true if the object is a code object. Code objects provide these attributes: co_argcount number of arguments (not including * or ** args) co_code string of raw compiled bytecode co_consts tuple of constants used in the bytecode co_filename name of file in which this code object was created co_firstlineno number of first line in Python source code co_flags bitmap: 1=optimized | 2=newlocals | 4=*arg | 8=**arg co_lnotab encoded mapping of line numbers to bytecode indices co_name name with which this code object was defined co_names tuple of names of local variables co_nlocals number of local variables co_stacksize virtual machine stack space required co_varnames tuple of names of arguments and local variables""" return isinstance(object, types.CodeType) def isbuiltin(object): """Return true if the object is a built-in function or method. Built-in functions and methods provide these attributes: __doc__ documentation string __name__ original name of this function or method __self__ instance to which a method is bound, or None""" return isinstance(object, types.BuiltinFunctionType) def isroutine(object): """Return true if the object is any kind of function or method.""" return (isbuiltin(object) or isfunction(object) or ismethod(object) or ismethoddescriptor(object)) def isabstract(object): """Return true if the object is an abstract base class (ABC).""" return bool(isinstance(object, type) and object.__flags__ & TPFLAGS_IS_ABSTRACT) def getmembers(object, predicate=None): """Return all members of an object as (name, value) pairs sorted by name. Optionally, only return members that satisfy a given predicate.""" results = [] for key in dir(object): try: value = getattr(object, key) except AttributeError: continue if not predicate or predicate(value): results.append((key, value)) results.sort() return results Attribute = namedtuple('Attribute', 'name kind defining_class object') def classify_class_attrs(cls): """Return list of attribute-descriptor tuples. For each name in dir(cls), the return list contains a 4-tuple with these elements: 0. The name (a string). 1. The kind of attribute this is, one of these strings: 'class method' created via classmethod() 'static method' created via staticmethod() 'property' created via property() 'method' any other flavor of method 'data' not a method 2. The class which defined this attribute (a class). 3. The object as obtained directly from the defining class's __dict__, not via getattr. This is especially important for data attributes: C.data is just a data object, but C.__dict__['data'] may be a data descriptor with additional info, like a __doc__ string. """ mro = getmro(cls) names = dir(cls) result = [] for name in names: # Get the object associated with the name, and where it was defined. # Getting an obj from the __dict__ sometimes reveals more than # using getattr. Static and class methods are dramatic examples. # Furthermore, some objects may raise an Exception when fetched with # getattr(). This is the case with some descriptors (bug #1785). # Thus, we only use getattr() as a last resort. homecls = None for base in (cls,) + mro: if name in base.__dict__: obj = base.__dict__[name] homecls = base break else: obj = getattr(cls, name) homecls = getattr(obj, "__objclass__", homecls) # Classify the object. if isinstance(obj, staticmethod): kind = "static method" elif isinstance(obj, classmethod): kind = "class method" elif isinstance(obj, property): kind = "property" elif ismethoddescriptor(obj): kind = "method" elif isdatadescriptor(obj): kind = "data" else: obj_via_getattr = getattr(cls, name) if (ismethod(obj_via_getattr) or ismethoddescriptor(obj_via_getattr)): kind = "method" else: kind = "data" obj = obj_via_getattr result.append(Attribute(name, kind, homecls, obj)) return result # ----------------------------------------------------------- class helpers def _searchbases(cls, accum): # Simulate the "classic class" search order. if cls in accum: return accum.append(cls) for base in cls.__bases__: _searchbases(base, accum) def getmro(cls): "Return tuple of base classes (including cls) in method resolution order." if hasattr(cls, "__mro__"): return cls.__mro__ else: result = [] _searchbases(cls, result) return tuple(result) # -------------------------------------------------- source code extraction def indentsize(line): """Return the indent size, in spaces, at the start of a line of text.""" expline = string.expandtabs(line) return len(expline) - len(string.lstrip(expline)) def getdoc(object): """Get the documentation string for an object. All tabs are expanded to spaces. To clean up docstrings that are indented to line up with blocks of code, any whitespace than can be uniformly removed from the second line onwards is removed.""" try: doc = object.__doc__ except AttributeError: return None if not isinstance(doc, types.StringTypes): return None return cleandoc(doc) def cleandoc(doc): """Clean up indentation from docstrings. Any whitespace that can be uniformly removed from the second line onwards is removed.""" try: lines = string.split(string.expandtabs(doc), '\n') except UnicodeError: return None else: # Find minimum indentation of any non-blank lines after first line. margin = sys.maxint for line in lines[1:]: content = len(string.lstrip(line)) if content: indent = len(line) - content margin = min(margin, indent) # Remove indentation. if lines: lines[0] = lines[0].lstrip() if margin < sys.maxint: for i in range(1, len(lines)): lines[i] = lines[i][margin:] # Remove any trailing or leading blank lines. while lines and not lines[-1]: lines.pop() while lines and not lines[0]: lines.pop(0) return string.join(lines, '\n') def getfile(object): """Work out which source or compiled file an object was defined in.""" if ismodule(object): if hasattr(object, '__file__'): return object.__file__ raise TypeError('{!r} is a built-in module'.format(object)) if isclass(object): object = sys.modules.get(object.__module__) if hasattr(object, '__file__'): return object.__file__ raise TypeError('{!r} is a built-in class'.format(object)) if ismethod(object): object = object.im_func if isfunction(object): object = object.func_code if istraceback(object): object = object.tb_frame if isframe(object): object = object.f_code if iscode(object): return object.co_filename raise TypeError('{!r} is not a module, class, method, ' 'function, traceback, frame, or code object'.format(object)) ModuleInfo = namedtuple('ModuleInfo', 'name suffix mode module_type') def getmoduleinfo(path): """Get the module name, suffix, mode, and module type for a given file.""" filename = os.path.basename(path) suffixes = map(lambda info: (-len(info[0]), info[0], info[1], info[2]), imp.get_suffixes()) suffixes.sort() # try longest suffixes first, in case they overlap for neglen, suffix, mode, mtype in suffixes: if filename[neglen:] == suffix: return ModuleInfo(filename[:neglen], suffix, mode, mtype) def getmodulename(path): """Return the module name for a given file, or None.""" info = getmoduleinfo(path) if info: return info[0] def getsourcefile(object): """Return the filename that can be used to locate an object's source. Return None if no way can be identified to get the source. """ filename = getfile(object) if string.lower(filename[-4:]) in ('.pyc', '.pyo'): filename = filename[:-4] + '.py' for suffix, mode, kind in imp.get_suffixes(): if 'b' in mode and string.lower(filename[-len(suffix):]) == suffix: # Looks like a binary file. We want to only return a text file. return None if os.path.exists(filename): return filename # only return a non-existent filename if the module has a PEP 302 loader if hasattr(getmodule(object, filename), '__loader__'): return filename # or it is in the linecache if filename in linecache.cache: return filename def getabsfile(object, _filename=None): """Return an absolute path to the source or compiled file for an object. The idea is for each object to have a unique origin, so this routine normalizes the result as much as possible.""" if _filename is None: _filename = getsourcefile(object) or getfile(object) return os.path.normcase(os.path.abspath(_filename)) modulesbyfile = {} _filesbymodname = {} def getmodule(object, _filename=None): """Return the module an object was defined in, or None if not found.""" if ismodule(object): return object if hasattr(object, '__module__'): return sys.modules.get(object.__module__) # Try the filename to modulename cache if _filename is not None and _filename in modulesbyfile: return sys.modules.get(modulesbyfile[_filename]) # Try the cache again with the absolute file name try: file = getabsfile(object, _filename) except TypeError: return None if file in modulesbyfile: return sys.modules.get(modulesbyfile[file]) # Update the filename to module name cache and check yet again # Copy sys.modules in order to cope with changes while iterating for modname, module in sys.modules.items(): if ismodule(module) and hasattr(module, '__file__'): f = module.__file__ if f == _filesbymodname.get(modname, None): # Have already mapped this module, so skip it continue _filesbymodname[modname] = f f = getabsfile(module) # Always map to the name the module knows itself by modulesbyfile[f] = modulesbyfile[ os.path.realpath(f)] = module.__name__ if file in modulesbyfile: return sys.modules.get(modulesbyfile[file]) # Check the main module main = sys.modules['__main__'] if not hasattr(object, '__name__'): return None if hasattr(main, object.__name__): mainobject = getattr(main, object.__name__) if mainobject is object: return main # Check builtins builtin = sys.modules['__builtin__'] if hasattr(builtin, object.__name__): builtinobject = getattr(builtin, object.__name__) if builtinobject is object: return builtin def findsource(object): """Return the entire source file and starting line number for an object. The argument may be a module, class, method, function, traceback, frame, or code object. The source code is returned as a list of all the lines in the file and the line number indexes a line in that list. An IOError is raised if the source code cannot be retrieved.""" file = getfile(object) sourcefile = getsourcefile(object) if not sourcefile and file[:1] + file[-1:] != '<>': raise IOError('source code not available') file = sourcefile if sourcefile else file module = getmodule(object, file) if module: lines = linecache.getlines(file, module.__dict__) else: lines = linecache.getlines(file) if not lines: raise IOError('could not get source code') if ismodule(object): return lines, 0 if isclass(object): name = object.__name__ pat = re.compile(r'^(\s*)class\s*' + name + r'\b') # make some effort to find the best matching class definition: # use the one with the least indentation, which is the one # that's most probably not inside a function definition. candidates = [] for i in range(len(lines)): match = pat.match(lines[i]) if match: # if it's at toplevel, it's already the best one if lines[i][0] == 'c': return lines, i # else add whitespace to candidate list candidates.append((match.group(1), i)) if candidates: # this will sort by whitespace, and by line number, # less whitespace first candidates.sort() return lines, candidates[0][1] else: raise IOError('could not find class definition') if ismethod(object): object = object.im_func if isfunction(object): object = object.func_code if istraceback(object): object = object.tb_frame if isframe(object): object = object.f_code if iscode(object): if not hasattr(object, 'co_firstlineno'): raise IOError('could not find function definition') lnum = object.co_firstlineno - 1 pat = re.compile(r'^(\s*def\s)|(.*(?<!\w)lambda(:|\s))|^(\s*@)') while lnum > 0: if pat.match(lines[lnum]): break lnum = lnum - 1 return lines, lnum raise IOError('could not find code object') def getcomments(object): """Get lines of comments immediately preceding an object's source code. Returns None when source can't be found. """ try: lines, lnum = findsource(object) except (IOError, TypeError): return None if ismodule(object): # Look for a comment block at the top of the file. start = 0 if lines and lines[0][:2] == '#!': start = 1 while start < len(lines) and string.strip(lines[start]) in ('', '#'): start = start + 1 if start < len(lines) and lines[start][:1] == '#': comments = [] end = start while end < len(lines) and lines[end][:1] == '#': comments.append(string.expandtabs(lines[end])) end = end + 1 return string.join(comments, '') # Look for a preceding block of comments at the same indentation. elif lnum > 0: indent = indentsize(lines[lnum]) end = lnum - 1 if end >= 0 and string.lstrip(lines[end])[:1] == '#' and \ indentsize(lines[end]) == indent: comments = [string.lstrip(string.expandtabs(lines[end]))] if end > 0: end = end - 1 comment = string.lstrip(string.expandtabs(lines[end])) while comment[:1] == '#' and indentsize(lines[end]) == indent: comments[:0] = [comment] end = end - 1 if end < 0: break comment = string.lstrip(string.expandtabs(lines[end])) while comments and string.strip(comments[0]) == '#': comments[:1] = [] while comments and string.strip(comments[-1]) == '#': comments[-1:] = [] return string.join(comments, '') class EndOfBlock(Exception): pass class BlockFinder: """Provide a tokeneater() method to detect the end of a code block.""" def __init__(self): self.indent = 0 self.islambda = False self.started = False self.passline = False self.last = 1 def tokeneater(self, type, token, srow_scol, erow_ecol, line): srow, scol = srow_scol erow, ecol = erow_ecol if not self.started: # look for the first "def", "class" or "lambda" if token in ("def", "class", "lambda"): if token == "lambda": self.islambda = True self.started = True self.passline = True # skip to the end of the line elif type == tokenize.NEWLINE: self.passline = False # stop skipping when a NEWLINE is seen self.last = srow if self.islambda: # lambdas always end at the first NEWLINE raise EndOfBlock elif self.passline: pass elif type == tokenize.INDENT: self.indent = self.indent + 1 self.passline = True elif type == tokenize.DEDENT: self.indent = self.indent - 1 # the end of matching indent/dedent pairs end a block # (note that this only works for "def"/"class" blocks, # not e.g. for "if: else:" or "try: finally:" blocks) if self.indent <= 0: raise EndOfBlock elif self.indent == 0 and type not in (tokenize.COMMENT, tokenize.NL): # any other token on the same indentation level end the previous # block as well, except the pseudo-tokens COMMENT and NL. raise EndOfBlock def getblock(lines): """Extract the block of code at the top of the given list of lines.""" blockfinder = BlockFinder() try: tokenize.tokenize(iter(lines).next, blockfinder.tokeneater) except (EndOfBlock, IndentationError): pass return lines[:blockfinder.last] def getsourcelines(object): """Return a list of source lines and starting line number for an object. The argument may be a module, class, method, function, traceback, frame, or code object. The source code is returned as a list of the lines corresponding to the object and the line number indicates where in the original source file the first line of code was found. An IOError is raised if the source code cannot be retrieved.""" lines, lnum = findsource(object) if istraceback(object): object = object.tb_frame # for module or frame that corresponds to module, return all source lines if (ismodule(object) or (isframe(object) and object.f_code.co_name == "<module>")): return lines, 0 else: return getblock(lines[lnum:]), lnum + 1 def getsource(object): """Return the text of the source code for an object. The argument may be a module, class, method, function, traceback, frame, or code object. The source code is returned as a single string. An IOError is raised if the source code cannot be retrieved.""" lines, lnum = getsourcelines(object) return string.join(lines, '') # --------------------------------------------------- class tree extraction def walktree(classes, children, parent): """Recursive helper function for getclasstree().""" results = [] classes.sort(key=attrgetter('__module__', '__name__')) for c in classes: results.append((c, c.__bases__)) if c in children: results.append(walktree(children[c], children, c)) return results def getclasstree(classes, unique=0): """Arrange the given list of classes into a hierarchy of nested lists. Where a nested list appears, it contains classes derived from the class whose entry immediately precedes the list. Each entry is a 2-tuple containing a class and a tuple of its base classes. If the 'unique' argument is true, exactly one entry appears in the returned structure for each class in the given list. Otherwise, classes using multiple inheritance and their descendants will appear multiple times.""" children = {} roots = [] for c in classes: if c.__bases__: for parent in c.__bases__: if not parent in children: children[parent] = [] if c not in children[parent]: children[parent].append(c) if unique and parent in classes: break elif c not in roots: roots.append(c) for parent in children: if parent not in classes: roots.append(parent) return walktree(roots, children, None) # ------------------------------------------------ argument list extraction Arguments = namedtuple('Arguments', 'args varargs keywords') def getargs(co): """Get information about the arguments accepted by a code object. Three things are returned: (args, varargs, varkw), where 'args' is a list of argument names (possibly containing nested lists), and 'varargs' and 'varkw' are the names of the * and ** arguments or None.""" if not iscode(co): raise TypeError('{!r} is not a code object'.format(co)) nargs = co.co_argcount names = co.co_varnames args = list(names[:nargs]) step = 0 # The following acrobatics are for anonymous (tuple) arguments. for i in range(nargs): if args[i][:1] in ('', '.'): stack, remain, count = [], [], [] while step < len(co.co_code): op = ord(co.co_code[step]) step = step + 1 if op >= dis.HAVE_ARGUMENT: opname = dis.opname[op] value = ord(co.co_code[step]) + ord(co.co_code[step+1])*256 step = step + 2 if opname in ('UNPACK_TUPLE', 'UNPACK_SEQUENCE'): remain.append(value) count.append(value) elif opname in ('STORE_FAST', 'STORE_DEREF'): if opname == 'STORE_FAST': stack.append(names[value]) else: stack.append(co.co_cellvars[value]) # Special case for sublists of length 1: def foo((bar)) # doesn't generate the UNPACK_TUPLE bytecode, so if # `remain` is empty here, we have such a sublist. if not remain: stack[0] = [stack[0]] break else: remain[-1] = remain[-1] - 1 while remain[-1] == 0: remain.pop() size = count.pop() stack[-size:] = [stack[-size:]] if not remain: break remain[-1] = remain[-1] - 1 if not remain: break args[i] = stack[0] varargs = None if co.co_flags & CO_VARARGS: varargs = co.co_varnames[nargs] nargs = nargs + 1 varkw = None if co.co_flags & CO_VARKEYWORDS: varkw = co.co_varnames[nargs] return Arguments(args, varargs, varkw) ArgSpec = namedtuple('ArgSpec', 'args varargs keywords defaults') def getargspec(func): """Get the names and default values of a function's arguments. A tuple of four things is returned: (args, varargs, varkw, defaults). 'args' is a list of the argument names (it may contain nested lists). 'varargs' and 'varkw' are the names of the * and ** arguments or None. 'defaults' is an n-tuple of the default values of the last n arguments. """ if ismethod(func): func = func.im_func if not isfunction(func): raise TypeError('{!r} is not a Python function'.format(func)) args, varargs, varkw = getargs(func.func_code) return ArgSpec(args, varargs, varkw, func.func_defaults) ArgInfo = namedtuple('ArgInfo', 'args varargs keywords locals') def getargvalues(frame): """Get information about arguments passed into a particular frame. A tuple of four things is returned: (args, varargs, varkw, locals). 'args' is a list of the argument names (it may contain nested lists). 'varargs' and 'varkw' are the names of the * and ** arguments or None. 'locals' is the locals dictionary of the given frame.""" args, varargs, varkw = getargs(frame.f_code) return ArgInfo(args, varargs, varkw, frame.f_locals) def joinseq(seq): if len(seq) == 1: return '(' + seq[0] + ',)' else: return '(' + string.join(seq, ', ') + ')' def strseq(object, convert, join=joinseq): """Recursively walk a sequence, stringifying each element.""" if type(object) in (list, tuple): return join(map(lambda o, c=convert, j=join: strseq(o, c, j), object)) else: return convert(object) def formatargspec(args, varargs=None, varkw=None, defaults=None, formatarg=str, formatvarargs=lambda name: '*' + name, formatvarkw=lambda name: '**' + name, formatvalue=lambda value: '=' + repr(value), join=joinseq): """Format an argument spec from the 4 values returned by getargspec. The first four arguments are (args, varargs, varkw, defaults). The other four arguments are the corresponding optional formatting functions that are called to turn names and values into strings. The ninth argument is an optional function to format the sequence of arguments.""" specs = [] if defaults: firstdefault = len(args) - len(defaults) for i, arg in enumerate(args): spec = strseq(arg, formatarg, join) if defaults and i >= firstdefault: spec = spec + formatvalue(defaults[i - firstdefault]) specs.append(spec) if varargs is not None: specs.append(formatvarargs(varargs)) if varkw is not None: specs.append(formatvarkw(varkw)) return '(' + string.join(specs, ', ') + ')' def formatargvalues(args, varargs, varkw, locals, formatarg=str, formatvarargs=lambda name: '*' + name, formatvarkw=lambda name: '**' + name, formatvalue=lambda value: '=' + repr(value), join=joinseq): """Format an argument spec from the 4 values returned by getargvalues. The first four arguments are (args, varargs, varkw, locals). The next four arguments are the corresponding optional formatting functions that are called to turn names and values into strings. The ninth argument is an optional function to format the sequence of arguments.""" def convert(name, locals=locals, formatarg=formatarg, formatvalue=formatvalue): return formatarg(name) + formatvalue(locals[name]) specs = [] for i in range(len(args)): specs.append(strseq(args[i], convert, join)) if varargs: specs.append(formatvarargs(varargs) + formatvalue(locals[varargs])) if varkw: specs.append(formatvarkw(varkw) + formatvalue(locals[varkw])) return '(' + string.join(specs, ', ') + ')' def getcallargs(func, *positional, **named): """Get the mapping of arguments to values. A dict is returned, with keys the function argument names (including the names of the * and ** arguments, if any), and values the respective bound values from 'positional' and 'named'.""" args, varargs, varkw, defaults = getargspec(func) f_name = func.__name__ arg2value = {} # The following closures are basically because of tuple parameter unpacking. assigned_tuple_params = [] def assign(arg, value): if isinstance(arg, str): arg2value[arg] = value else: assigned_tuple_params.append(arg) value = iter(value) for i, subarg in enumerate(arg): try: subvalue = next(value) except StopIteration: raise ValueError('need more than %d %s to unpack' % (i, 'values' if i > 1 else 'value')) assign(subarg,subvalue) try: next(value) except StopIteration: pass else: raise ValueError('too many values to unpack') def is_assigned(arg): if isinstance(arg,str): return arg in arg2value return arg in assigned_tuple_params if ismethod(func) and func.im_self is not None: # implicit 'self' (or 'cls' for classmethods) argument positional = (func.im_self,) + positional num_pos = len(positional) num_total = num_pos + len(named) num_args = len(args) num_defaults = len(defaults) if defaults else 0 for arg, value in zip(args, positional): assign(arg, value) if varargs: if num_pos > num_args: assign(varargs, positional[-(num_pos-num_args):]) else: assign(varargs, ()) elif 0 < num_args < num_pos: raise TypeError('%s() takes %s %d %s (%d given)' % ( f_name, 'at most' if defaults else 'exactly', num_args, 'arguments' if num_args > 1 else 'argument', num_total)) elif num_args == 0 and num_total: if varkw: if num_pos: # XXX: We should use num_pos, but Python also uses num_total: raise TypeError('%s() takes exactly 0 arguments ' '(%d given)' % (f_name, num_total)) else: raise TypeError('%s() takes no arguments (%d given)' % (f_name, num_total)) for arg in args: if isinstance(arg, str) and arg in named: if is_assigned(arg): raise TypeError("%s() got multiple values for keyword " "argument '%s'" % (f_name, arg)) else: assign(arg, named.pop(arg)) if defaults: # fill in any missing values with the defaults for arg, value in zip(args[-num_defaults:], defaults): if not is_assigned(arg): assign(arg, value) if varkw: assign(varkw, named) elif named: unexpected = next(iter(named)) try: unicode except NameError: pass else: if isinstance(unexpected, unicode): unexpected = unexpected.encode(sys.getdefaultencoding(), 'replace') raise TypeError("%s() got an unexpected keyword argument '%s'" % (f_name, unexpected)) unassigned = num_args - len([arg for arg in args if is_assigned(arg)]) if unassigned: num_required = num_args - num_defaults raise TypeError('%s() takes %s %d %s (%d given)' % ( f_name, 'at least' if defaults else 'exactly', num_required, 'arguments' if num_required > 1 else 'argument', num_total)) return arg2value # -------------------------------------------------- stack frame extraction Traceback = namedtuple('Traceback', 'filename lineno function code_context index') def getframeinfo(frame, context=1): """Get information about a frame or traceback object. A tuple of five things is returned: the filename, the line number of the current line, the function name, a list of lines of context from the source code, and the index of the current line within that list. The optional second argument specifies the number of lines of context to return, which are centered around the current line.""" if istraceback(frame): lineno = frame.tb_lineno frame = frame.tb_frame else: lineno = frame.f_lineno if not isframe(frame): raise TypeError('{!r} is not a frame or traceback object'.format(frame)) filename = getsourcefile(frame) or getfile(frame) if context > 0: start = lineno - 1 - context//2 try: lines, lnum = findsource(frame) except IOError: lines = index = None else: start = max(start, 1) start = max(0, min(start, len(lines) - context)) lines = lines[start:start+context] index = lineno - 1 - start else: lines = index = None return Traceback(filename, lineno, frame.f_code.co_name, lines, index) def getlineno(frame): """Get the line number from a frame object, allowing for optimization.""" # FrameType.f_lineno is now a descriptor that grovels co_lnotab return frame.f_lineno def getouterframes(frame, context=1): """Get a list of records for a frame and all higher (calling) frames. Each record contains a frame object, filename, line number, function name, a list of lines of context, and index within the context.""" framelist = [] while frame: framelist.append((frame,) + getframeinfo(frame, context)) frame = frame.f_back return framelist def getinnerframes(tb, context=1): """Get a list of records for a traceback's frame and all lower frames. Each record contains a frame object, filename, line number, function name, a list of lines of context, and index within the context.""" framelist = [] while tb: framelist.append((tb.tb_frame,) + getframeinfo(tb, context)) tb = tb.tb_next return framelist if hasattr(sys, '_getframe'): currentframe = sys._getframe else: currentframe = lambda _=None: None def stack(context=1): """Return a list of records for the stack above the caller's frame.""" return getouterframes(sys._getframe(1), context) def trace(context=1): """Return a list of records for the stack below the current exception.""" return getinnerframes(sys.exc_info()[2], context)
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