diff options
Diffstat (limited to 'lib/python2.7/inspect.py')
| -rw-r--r-- | lib/python2.7/inspect.py | 1058 |
1 files changed, 1058 insertions, 0 deletions
diff --git a/lib/python2.7/inspect.py b/lib/python2.7/inspect.py new file mode 100644 index 0000000..9e928b2 --- /dev/null +++ b/lib/python2.7/inspect.py @@ -0,0 +1,1058 @@ +# -*- 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 provides same attributes as functions. + + See help(isfunction) for attributes listing.""" + 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 interation 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 ismodule(object): 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] = [] + 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 == 'STORE_FAST': + stack.append(names[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)) + 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) |