| """Get useful information from live Python objects. |
| |
| This module encapsulates the interface provided by the internal special |
| attributes (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 |
| getfullargspec() - same, with support for Python-3000 features |
| 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 |
| |
| signature() - get a Signature object for the callable |
| """ |
| |
| # This module is in the public domain. No warranties. |
| |
| __author__ = ('Ka-Ping Yee <ping@lfw.org>', |
| 'Yury Selivanov <yselivanov@sprymix.com>') |
| |
| import imp |
| import importlib.machinery |
| import itertools |
| import linecache |
| import os |
| import re |
| import sys |
| import tokenize |
| import types |
| import warnings |
| import functools |
| import builtins |
| from operator import attrgetter |
| from collections import namedtuple, OrderedDict |
| |
| # Create constants for the compiler flags in Include/code.h |
| # We try to get them from dis to avoid duplication, but fall |
| # back to hardcoding so the dependency is optional |
| try: |
| from dis import COMPILER_FLAG_NAMES as _flag_names |
| except ImportError: |
| CO_OPTIMIZED, CO_NEWLOCALS = 0x1, 0x2 |
| CO_VARARGS, CO_VARKEYWORDS = 0x4, 0x8 |
| CO_NESTED, CO_GENERATOR, CO_NOFREE = 0x10, 0x20, 0x40 |
| else: |
| mod_dict = globals() |
| for k, v in _flag_names.items(): |
| mod_dict["CO_" + v] = k |
| |
| # 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: |
| __cached__ pathname to byte compiled file |
| __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) |
| |
| 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 |
| __func__ function object containing implementation of method |
| __self__ instance to which this method is bound""" |
| 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 |
| __func__ attribute (etc) when an object passes ismethod().""" |
| if isclass(object) or ismethod(object) or isfunction(object): |
| # mutual exclusion |
| return False |
| tp = type(object) |
| return hasattr(tp, "__get__") and not hasattr(tp, "__set__") |
| |
| 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.""" |
| if isclass(object) or ismethod(object) or isfunction(object): |
| # mutual exclusion |
| return False |
| tp = type(object) |
| return hasattr(tp, "__set__") and hasattr(tp, "__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 |
| __code__ code object containing compiled function bytecode |
| __defaults__ tuple of any default values for arguments |
| __globals__ global namespace in which this function was defined |
| __annotations__ dict of parameter annotations |
| __kwdefaults__ dict of keyword only parameters with defaults""" |
| 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.__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_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_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.""" |
| if isclass(object): |
| mro = (object,) + getmro(object) |
| else: |
| mro = () |
| results = [] |
| for key in dir(object): |
| # First try to get the value via __dict__. Some descriptors don't |
| # like calling their __get__ (see bug #1785). |
| for base in mro: |
| if key in base.__dict__: |
| value = base.__dict__[key] |
| break |
| else: |
| 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 (isfunction(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 getmro(cls): |
| "Return tuple of base classes (including cls) in method resolution order." |
| return cls.__mro__ |
| |
| # -------------------------------------------------- source code extraction |
| def indentsize(line): |
| """Return the indent size, in spaces, at the start of a line of text.""" |
| expline = line.expandtabs() |
| return len(expline) - len(expline.lstrip()) |
| |
| 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, str): |
| 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 = doc.expandtabs().split('\n') |
| except UnicodeError: |
| return None |
| else: |
| # Find minimum indentation of any non-blank lines after first line. |
| margin = sys.maxsize |
| for line in lines[1:]: |
| content = len(line.lstrip()) |
| if content: |
| indent = len(line) - content |
| margin = min(margin, indent) |
| # Remove indentation. |
| if lines: |
| lines[0] = lines[0].lstrip() |
| if margin < sys.maxsize: |
| 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 '\n'.join(lines) |
| |
| 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.__func__ |
| if isfunction(object): |
| object = object.__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.""" |
| warnings.warn('inspect.getmoduleinfo() is deprecated', DeprecationWarning, |
| 2) |
| filename = os.path.basename(path) |
| suffixes = [(-len(suffix), suffix, mode, mtype) |
| for suffix, mode, mtype in 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.""" |
| fname = os.path.basename(path) |
| # Check for paths that look like an actual module file |
| suffixes = [(-len(suffix), suffix) |
| for suffix in importlib.machinery.all_suffixes()] |
| suffixes.sort() # try longest suffixes first, in case they overlap |
| for neglen, suffix in suffixes: |
| if fname.endswith(suffix): |
| return fname[:neglen] |
| return None |
| |
| 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) |
| all_bytecode_suffixes = importlib.machinery.DEBUG_BYTECODE_SUFFIXES[:] |
| all_bytecode_suffixes += importlib.machinery.OPTIMIZED_BYTECODE_SUFFIXES[:] |
| if any(filename.endswith(s) for s in all_bytecode_suffixes): |
| filename = (os.path.splitext(filename)[0] + |
| importlib.machinery.SOURCE_SUFFIXES[0]) |
| elif any(filename.endswith(s) for s in |
| importlib.machinery.EXTENSION_SUFFIXES): |
| 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 list(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['builtins'] |
| 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.__func__ |
| if isfunction(object): |
| object = object.__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 lines[start].strip() 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(lines[end].expandtabs()) |
| end = end + 1 |
| return ''.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 lines[end].lstrip()[:1] == '#' and \ |
| indentsize(lines[end]) == indent: |
| comments = [lines[end].expandtabs().lstrip()] |
| if end > 0: |
| end = end - 1 |
| comment = lines[end].expandtabs().lstrip() |
| while comment[:1] == '#' and indentsize(lines[end]) == indent: |
| comments[:0] = [comment] |
| end = end - 1 |
| if end < 0: break |
| comment = lines[end].expandtabs().lstrip() |
| while comments and comments[0].strip() == '#': |
| comments[:1] = [] |
| while comments and comments[-1].strip() == '#': |
| comments[-1:] = [] |
| return ''.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, srowcol, erowcol, line): |
| 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 = srowcol[0] |
| 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: |
| tokens = tokenize.generate_tokens(iter(lines).__next__) |
| for _token in tokens: |
| blockfinder.tokeneater(*_token) |
| 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 ''.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=False): |
| """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, varkw') |
| |
| def getargs(co): |
| """Get information about the arguments accepted by a code object. |
| |
| Three things are returned: (args, varargs, varkw), where |
| 'args' is the list of argument names. Keyword-only arguments are |
| appended. 'varargs' and 'varkw' are the names of the * and ** |
| arguments or None.""" |
| args, varargs, kwonlyargs, varkw = _getfullargs(co) |
| return Arguments(args + kwonlyargs, varargs, varkw) |
| |
| def _getfullargs(co): |
| """Get information about the arguments accepted by a code object. |
| |
| Four things are returned: (args, varargs, kwonlyargs, varkw), where |
| 'args' and 'kwonlyargs' are lists of argument names, 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 |
| nkwargs = co.co_kwonlyargcount |
| args = list(names[:nargs]) |
| kwonlyargs = list(names[nargs:nargs+nkwargs]) |
| step = 0 |
| |
| nargs += nkwargs |
| 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 args, varargs, kwonlyargs, 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. |
| 'args' will include keyword-only argument names. |
| '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. |
| |
| Use the getfullargspec() API for Python-3000 code, as annotations |
| and keyword arguments are supported. getargspec() will raise ValueError |
| if the func has either annotations or keyword arguments. |
| """ |
| |
| args, varargs, varkw, defaults, kwonlyargs, kwonlydefaults, ann = \ |
| getfullargspec(func) |
| if kwonlyargs or ann: |
| raise ValueError("Function has keyword-only arguments or annotations" |
| ", use getfullargspec() API which can support them") |
| return ArgSpec(args, varargs, varkw, defaults) |
| |
| FullArgSpec = namedtuple('FullArgSpec', |
| 'args, varargs, varkw, defaults, kwonlyargs, kwonlydefaults, annotations') |
| |
| def getfullargspec(func): |
| """Get the names and default values of a function's arguments. |
| |
| A tuple of seven things is returned: |
| (args, varargs, varkw, defaults, kwonlyargs, kwonlydefaults annotations). |
| 'args' is a list of the argument names. |
| '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. |
| 'kwonlyargs' is a list of keyword-only argument names. |
| 'kwonlydefaults' is a dictionary mapping names from kwonlyargs to defaults. |
| 'annotations' is a dictionary mapping argument names to annotations. |
| |
| The first four items in the tuple correspond to getargspec(). |
| """ |
| |
| if ismethod(func): |
| func = func.__func__ |
| if not isfunction(func): |
| raise TypeError('{!r} is not a Python function'.format(func)) |
| args, varargs, kwonlyargs, varkw = _getfullargs(func.__code__) |
| return FullArgSpec(args, varargs, varkw, func.__defaults__, |
| kwonlyargs, func.__kwdefaults__, func.__annotations__) |
| |
| 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. |
| '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 formatannotation(annotation, base_module=None): |
| if isinstance(annotation, type): |
| if annotation.__module__ in ('builtins', base_module): |
| return annotation.__name__ |
| return annotation.__module__+'.'+annotation.__name__ |
| return repr(annotation) |
| |
| def formatannotationrelativeto(object): |
| module = getattr(object, '__module__', None) |
| def _formatannotation(annotation): |
| return formatannotation(annotation, module) |
| return _formatannotation |
| |
| def formatargspec(args, varargs=None, varkw=None, defaults=None, |
| kwonlyargs=(), kwonlydefaults={}, annotations={}, |
| formatarg=str, |
| formatvarargs=lambda name: '*' + name, |
| formatvarkw=lambda name: '**' + name, |
| formatvalue=lambda value: '=' + repr(value), |
| formatreturns=lambda text: ' -> ' + text, |
| formatannotation=formatannotation): |
| """Format an argument spec from the values returned by getargspec |
| or getfullargspec. |
| |
| The first seven arguments are (args, varargs, varkw, defaults, |
| kwonlyargs, kwonlydefaults, annotations). The other five arguments |
| are the corresponding optional formatting functions that are called to |
| turn names and values into strings. The last argument is an optional |
| function to format the sequence of arguments.""" |
| def formatargandannotation(arg): |
| result = formatarg(arg) |
| if arg in annotations: |
| result += ': ' + formatannotation(annotations[arg]) |
| return result |
| specs = [] |
| if defaults: |
| firstdefault = len(args) - len(defaults) |
| for i, arg in enumerate(args): |
| spec = formatargandannotation(arg) |
| if defaults and i >= firstdefault: |
| spec = spec + formatvalue(defaults[i - firstdefault]) |
| specs.append(spec) |
| if varargs is not None: |
| specs.append(formatvarargs(formatargandannotation(varargs))) |
| else: |
| if kwonlyargs: |
| specs.append('*') |
| if kwonlyargs: |
| for kwonlyarg in kwonlyargs: |
| spec = formatargandannotation(kwonlyarg) |
| if kwonlydefaults and kwonlyarg in kwonlydefaults: |
| spec += formatvalue(kwonlydefaults[kwonlyarg]) |
| specs.append(spec) |
| if varkw is not None: |
| specs.append(formatvarkw(formatargandannotation(varkw))) |
| result = '(' + ', '.join(specs) + ')' |
| if 'return' in annotations: |
| result += formatreturns(formatannotation(annotations['return'])) |
| return result |
| |
| def formatargvalues(args, varargs, varkw, locals, |
| formatarg=str, |
| formatvarargs=lambda name: '*' + name, |
| formatvarkw=lambda name: '**' + name, |
| formatvalue=lambda value: '=' + repr(value)): |
| """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(convert(args[i])) |
| if varargs: |
| specs.append(formatvarargs(varargs) + formatvalue(locals[varargs])) |
| if varkw: |
| specs.append(formatvarkw(varkw) + formatvalue(locals[varkw])) |
| return '(' + ', '.join(specs) + ')' |
| |
| def _missing_arguments(f_name, argnames, pos, values): |
| names = [repr(name) for name in argnames if name not in values] |
| missing = len(names) |
| if missing == 1: |
| s = names[0] |
| elif missing == 2: |
| s = "{} and {}".format(*names) |
| else: |
| tail = ", {} and {}".format(names[-2:]) |
| del names[-2:] |
| s = ", ".join(names) + tail |
| raise TypeError("%s() missing %i required %s argument%s: %s" % |
| (f_name, missing, |
| "positional" if pos else "keyword-only", |
| "" if missing == 1 else "s", s)) |
| |
| def _too_many(f_name, args, kwonly, varargs, defcount, given, values): |
| atleast = len(args) - defcount |
| kwonly_given = len([arg for arg in kwonly if arg in values]) |
| if varargs: |
| plural = atleast != 1 |
| sig = "at least %d" % (atleast,) |
| elif defcount: |
| plural = True |
| sig = "from %d to %d" % (atleast, len(args)) |
| else: |
| plural = len(args) != 1 |
| sig = str(len(args)) |
| kwonly_sig = "" |
| if kwonly_given: |
| msg = " positional argument%s (and %d keyword-only argument%s)" |
| kwonly_sig = (msg % ("s" if given != 1 else "", kwonly_given, |
| "s" if kwonly_given != 1 else "")) |
| raise TypeError("%s() takes %s positional argument%s but %d%s %s given" % |
| (f_name, sig, "s" if plural else "", given, kwonly_sig, |
| "was" if given == 1 and not kwonly_given else "were")) |
| |
| 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'.""" |
| spec = getfullargspec(func) |
| args, varargs, varkw, defaults, kwonlyargs, kwonlydefaults, ann = spec |
| f_name = func.__name__ |
| arg2value = {} |
| |
| |
| if ismethod(func) and func.__self__ is not None: |
| # implicit 'self' (or 'cls' for classmethods) argument |
| positional = (func.__self__,) + positional |
| num_pos = len(positional) |
| num_args = len(args) |
| num_defaults = len(defaults) if defaults else 0 |
| |
| n = min(num_pos, num_args) |
| for i in range(n): |
| arg2value[args[i]] = positional[i] |
| if varargs: |
| arg2value[varargs] = tuple(positional[n:]) |
| possible_kwargs = set(args + kwonlyargs) |
| if varkw: |
| arg2value[varkw] = {} |
| for kw, value in named.items(): |
| if kw not in possible_kwargs: |
| if not varkw: |
| raise TypeError("%s() got an unexpected keyword argument %r" % |
| (f_name, kw)) |
| arg2value[varkw][kw] = value |
| continue |
| if kw in arg2value: |
| raise TypeError("%s() got multiple values for argument %r" % |
| (f_name, kw)) |
| arg2value[kw] = value |
| if num_pos > num_args and not varargs: |
| _too_many(f_name, args, kwonlyargs, varargs, num_defaults, |
| num_pos, arg2value) |
| if num_pos < num_args: |
| req = args[:num_args - num_defaults] |
| for arg in req: |
| if arg not in arg2value: |
| _missing_arguments(f_name, req, True, arg2value) |
| for i, arg in enumerate(args[num_args - num_defaults:]): |
| if arg not in arg2value: |
| arg2value[arg] = defaults[i] |
| missing = 0 |
| for kwarg in kwonlyargs: |
| if kwarg not in arg2value: |
| if kwarg in kwonlydefaults: |
| arg2value[kwarg] = kwonlydefaults[kwarg] |
| else: |
| missing += 1 |
| if missing: |
| _missing_arguments(f_name, kwonlyargs, False, arg2value) |
| return arg2value |
| |
| ClosureVars = namedtuple('ClosureVars', 'nonlocals globals builtins unbound') |
| |
| def getclosurevars(func): |
| """ |
| Get the mapping of free variables to their current values. |
| |
| Returns a named tuple of dicts mapping the current nonlocal, global |
| and builtin references as seen by the body of the function. A final |
| set of unbound names that could not be resolved is also provided. |
| """ |
| |
| if ismethod(func): |
| func = func.__func__ |
| |
| if not isfunction(func): |
| raise TypeError("'{!r}' is not a Python function".format(func)) |
| |
| code = func.__code__ |
| # Nonlocal references are named in co_freevars and resolved |
| # by looking them up in __closure__ by positional index |
| if func.__closure__ is None: |
| nonlocal_vars = {} |
| else: |
| nonlocal_vars = { |
| var : cell.cell_contents |
| for var, cell in zip(code.co_freevars, func.__closure__) |
| } |
| |
| # Global and builtin references are named in co_names and resolved |
| # by looking them up in __globals__ or __builtins__ |
| global_ns = func.__globals__ |
| builtin_ns = global_ns.get("__builtins__", builtins.__dict__) |
| if ismodule(builtin_ns): |
| builtin_ns = builtin_ns.__dict__ |
| global_vars = {} |
| builtin_vars = {} |
| unbound_names = set() |
| for name in code.co_names: |
| if name in ("None", "True", "False"): |
| # Because these used to be builtins instead of keywords, they |
| # may still show up as name references. We ignore them. |
| continue |
| try: |
| global_vars[name] = global_ns[name] |
| except KeyError: |
| try: |
| builtin_vars[name] = builtin_ns[name] |
| except KeyError: |
| unbound_names.add(name) |
| |
| return ClosureVars(nonlocal_vars, global_vars, |
| builtin_vars, unbound_names) |
| |
| # -------------------------------------------------- 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 |
| |
| def currentframe(): |
| """Return the frame of the caller or None if this is not possible.""" |
| return sys._getframe(1) if hasattr(sys, "_getframe") else 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) |
| |
| |
| # ------------------------------------------------ static version of getattr |
| |
| _sentinel = object() |
| |
| def _static_getmro(klass): |
| return type.__dict__['__mro__'].__get__(klass) |
| |
| def _check_instance(obj, attr): |
| instance_dict = {} |
| try: |
| instance_dict = object.__getattribute__(obj, "__dict__") |
| except AttributeError: |
| pass |
| return dict.get(instance_dict, attr, _sentinel) |
| |
| |
| def _check_class(klass, attr): |
| for entry in _static_getmro(klass): |
| if _shadowed_dict(type(entry)) is _sentinel: |
| try: |
| return entry.__dict__[attr] |
| except KeyError: |
| pass |
| return _sentinel |
| |
| def _is_type(obj): |
| try: |
| _static_getmro(obj) |
| except TypeError: |
| return False |
| return True |
| |
| def _shadowed_dict(klass): |
| dict_attr = type.__dict__["__dict__"] |
| for entry in _static_getmro(klass): |
| try: |
| class_dict = dict_attr.__get__(entry)["__dict__"] |
| except KeyError: |
| pass |
| else: |
| if not (type(class_dict) is types.GetSetDescriptorType and |
| class_dict.__name__ == "__dict__" and |
| class_dict.__objclass__ is entry): |
| return class_dict |
| return _sentinel |
| |
| def getattr_static(obj, attr, default=_sentinel): |
| """Retrieve attributes without triggering dynamic lookup via the |
| descriptor protocol, __getattr__ or __getattribute__. |
| |
| Note: this function may not be able to retrieve all attributes |
| that getattr can fetch (like dynamically created attributes) |
| and may find attributes that getattr can't (like descriptors |
| that raise AttributeError). It can also return descriptor objects |
| instead of instance members in some cases. See the |
| documentation for details. |
| """ |
| instance_result = _sentinel |
| if not _is_type(obj): |
| klass = type(obj) |
| dict_attr = _shadowed_dict(klass) |
| if (dict_attr is _sentinel or |
| type(dict_attr) is types.MemberDescriptorType): |
| instance_result = _check_instance(obj, attr) |
| else: |
| klass = obj |
| |
| klass_result = _check_class(klass, attr) |
| |
| if instance_result is not _sentinel and klass_result is not _sentinel: |
| if (_check_class(type(klass_result), '__get__') is not _sentinel and |
| _check_class(type(klass_result), '__set__') is not _sentinel): |
| return klass_result |
| |
| if instance_result is not _sentinel: |
| return instance_result |
| if klass_result is not _sentinel: |
| return klass_result |
| |
| if obj is klass: |
| # for types we check the metaclass too |
| for entry in _static_getmro(type(klass)): |
| if _shadowed_dict(type(entry)) is _sentinel: |
| try: |
| return entry.__dict__[attr] |
| except KeyError: |
| pass |
| if default is not _sentinel: |
| return default |
| raise AttributeError(attr) |
| |
| |
| # ------------------------------------------------ generator introspection |
| |
| GEN_CREATED = 'GEN_CREATED' |
| GEN_RUNNING = 'GEN_RUNNING' |
| GEN_SUSPENDED = 'GEN_SUSPENDED' |
| GEN_CLOSED = 'GEN_CLOSED' |
| |
| def getgeneratorstate(generator): |
| """Get current state of a generator-iterator. |
| |
| Possible states are: |
| GEN_CREATED: Waiting to start execution. |
| GEN_RUNNING: Currently being executed by the interpreter. |
| GEN_SUSPENDED: Currently suspended at a yield expression. |
| GEN_CLOSED: Execution has completed. |
| """ |
| if generator.gi_running: |
| return GEN_RUNNING |
| if generator.gi_frame is None: |
| return GEN_CLOSED |
| if generator.gi_frame.f_lasti == -1: |
| return GEN_CREATED |
| return GEN_SUSPENDED |
| |
| |
| def getgeneratorlocals(generator): |
| """ |
| Get the mapping of generator local variables to their current values. |
| |
| A dict is returned, with the keys the local variable names and values the |
| bound values.""" |
| |
| if not isgenerator(generator): |
| raise TypeError("'{!r}' is not a Python generator".format(generator)) |
| |
| frame = getattr(generator, "gi_frame", None) |
| if frame is not None: |
| return generator.gi_frame.f_locals |
| else: |
| return {} |
| |
| ############################################################################### |
| ### Function Signature Object (PEP 362) |
| ############################################################################### |
| |
| |
| _WrapperDescriptor = type(type.__call__) |
| _MethodWrapper = type(all.__call__) |
| |
| _NonUserDefinedCallables = (_WrapperDescriptor, |
| _MethodWrapper, |
| types.BuiltinFunctionType) |
| |
| |
| def _get_user_defined_method(cls, method_name): |
| try: |
| meth = getattr(cls, method_name) |
| except AttributeError: |
| return |
| else: |
| if not isinstance(meth, _NonUserDefinedCallables): |
| # Once '__signature__' will be added to 'C'-level |
| # callables, this check won't be necessary |
| return meth |
| |
| |
| def signature(obj): |
| '''Get a signature object for the passed callable.''' |
| |
| if not callable(obj): |
| raise TypeError('{!r} is not a callable object'.format(obj)) |
| |
| if isinstance(obj, types.MethodType): |
| # In this case we skip the first parameter of the underlying |
| # function (usually `self` or `cls`). |
| sig = signature(obj.__func__) |
| return sig.replace(parameters=tuple(sig.parameters.values())[1:]) |
| |
| try: |
| sig = obj.__signature__ |
| except AttributeError: |
| pass |
| else: |
| if sig is not None: |
| return sig |
| |
| try: |
| # Was this function wrapped by a decorator? |
| wrapped = obj.__wrapped__ |
| except AttributeError: |
| pass |
| else: |
| return signature(wrapped) |
| |
| if isinstance(obj, types.FunctionType): |
| return Signature.from_function(obj) |
| |
| if isinstance(obj, functools.partial): |
| sig = signature(obj.func) |
| |
| new_params = OrderedDict(sig.parameters.items()) |
| |
| partial_args = obj.args or () |
| partial_keywords = obj.keywords or {} |
| try: |
| ba = sig.bind_partial(*partial_args, **partial_keywords) |
| except TypeError as ex: |
| msg = 'partial object {!r} has incorrect arguments'.format(obj) |
| raise ValueError(msg) from ex |
| |
| for arg_name, arg_value in ba.arguments.items(): |
| param = new_params[arg_name] |
| if arg_name in partial_keywords: |
| # We set a new default value, because the following code |
| # is correct: |
| # |
| # >>> def foo(a): print(a) |
| # >>> print(partial(partial(foo, a=10), a=20)()) |
| # 20 |
| # >>> print(partial(partial(foo, a=10), a=20)(a=30)) |
| # 30 |
| # |
| # So, with 'partial' objects, passing a keyword argument is |
| # like setting a new default value for the corresponding |
| # parameter |
| # |
| # We also mark this parameter with '_partial_kwarg' |
| # flag. Later, in '_bind', the 'default' value of this |
| # parameter will be added to 'kwargs', to simulate |
| # the 'functools.partial' real call. |
| new_params[arg_name] = param.replace(default=arg_value, |
| _partial_kwarg=True) |
| |
| elif (param.kind not in (_VAR_KEYWORD, _VAR_POSITIONAL) and |
| not param._partial_kwarg): |
| new_params.pop(arg_name) |
| |
| return sig.replace(parameters=new_params.values()) |
| |
| sig = None |
| if isinstance(obj, type): |
| # obj is a class or a metaclass |
| |
| # First, let's see if it has an overloaded __call__ defined |
| # in its metaclass |
| call = _get_user_defined_method(type(obj), '__call__') |
| if call is not None: |
| sig = signature(call) |
| else: |
| # Now we check if the 'obj' class has a '__new__' method |
| new = _get_user_defined_method(obj, '__new__') |
| if new is not None: |
| sig = signature(new) |
| else: |
| # Finally, we should have at least __init__ implemented |
| init = _get_user_defined_method(obj, '__init__') |
| if init is not None: |
| sig = signature(init) |
| elif not isinstance(obj, _NonUserDefinedCallables): |
| # An object with __call__ |
| # We also check that the 'obj' is not an instance of |
| # _WrapperDescriptor or _MethodWrapper to avoid |
| # infinite recursion (and even potential segfault) |
| call = _get_user_defined_method(type(obj), '__call__') |
| if call is not None: |
| sig = signature(call) |
| |
| if sig is not None: |
| # For classes and objects we skip the first parameter of their |
| # __call__, __new__, or __init__ methods |
| return sig.replace(parameters=tuple(sig.parameters.values())[1:]) |
| |
| if isinstance(obj, types.BuiltinFunctionType): |
| # Raise a nicer error message for builtins |
| msg = 'no signature found for builtin function {!r}'.format(obj) |
| raise ValueError(msg) |
| |
| raise ValueError('callable {!r} is not supported by signature'.format(obj)) |
| |
| |
| class _void: |
| '''A private marker - used in Parameter & Signature''' |
| |
| |
| class _empty: |
| pass |
| |
| |
| class _ParameterKind(int): |
| def __new__(self, *args, name): |
| obj = int.__new__(self, *args) |
| obj._name = name |
| return obj |
| |
| def __str__(self): |
| return self._name |
| |
| def __repr__(self): |
| return '<_ParameterKind: {!r}>'.format(self._name) |
| |
| |
| _POSITIONAL_ONLY = _ParameterKind(0, name='POSITIONAL_ONLY') |
| _POSITIONAL_OR_KEYWORD = _ParameterKind(1, name='POSITIONAL_OR_KEYWORD') |
| _VAR_POSITIONAL = _ParameterKind(2, name='VAR_POSITIONAL') |
| _KEYWORD_ONLY = _ParameterKind(3, name='KEYWORD_ONLY') |
| _VAR_KEYWORD = _ParameterKind(4, name='VAR_KEYWORD') |
| |
| |
| class Parameter: |
| '''Represents a parameter in a function signature. |
| |
| Has the following public attributes: |
| |
| * name : str |
| The name of the parameter as a string. |
| * default : object |
| The default value for the parameter if specified. If the |
| parameter has no default value, this attribute is not set. |
| * annotation |
| The annotation for the parameter if specified. If the |
| parameter has no annotation, this attribute is not set. |
| * kind : str |
| Describes how argument values are bound to the parameter. |
| Possible values: `Parameter.POSITIONAL_ONLY`, |
| `Parameter.POSITIONAL_OR_KEYWORD`, `Parameter.VAR_POSITIONAL`, |
| `Parameter.KEYWORD_ONLY`, `Parameter.VAR_KEYWORD`. |
| ''' |
| |
| __slots__ = ('_name', '_kind', '_default', '_annotation', '_partial_kwarg') |
| |
| POSITIONAL_ONLY = _POSITIONAL_ONLY |
| POSITIONAL_OR_KEYWORD = _POSITIONAL_OR_KEYWORD |
| VAR_POSITIONAL = _VAR_POSITIONAL |
| KEYWORD_ONLY = _KEYWORD_ONLY |
| VAR_KEYWORD = _VAR_KEYWORD |
| |
| empty = _empty |
| |
| def __init__(self, name, kind, *, default=_empty, annotation=_empty, |
| _partial_kwarg=False): |
| |
| if kind not in (_POSITIONAL_ONLY, _POSITIONAL_OR_KEYWORD, |
| _VAR_POSITIONAL, _KEYWORD_ONLY, _VAR_KEYWORD): |
| raise ValueError("invalid value for 'Parameter.kind' attribute") |
| self._kind = kind |
| |
| if default is not _empty: |
| if kind in (_VAR_POSITIONAL, _VAR_KEYWORD): |
| msg = '{} parameters cannot have default values'.format(kind) |
| raise ValueError(msg) |
| self._default = default |
| self._annotation = annotation |
| |
| if name is None: |
| if kind != _POSITIONAL_ONLY: |
| raise ValueError("None is not a valid name for a " |
| "non-positional-only parameter") |
| self._name = name |
| else: |
| name = str(name) |
| if kind != _POSITIONAL_ONLY and not name.isidentifier(): |
| msg = '{!r} is not a valid parameter name'.format(name) |
| raise ValueError(msg) |
| self._name = name |
| |
| self._partial_kwarg = _partial_kwarg |
| |
| @property |
| def name(self): |
| return self._name |
| |
| @property |
| def default(self): |
| return self._default |
| |
| @property |
| def annotation(self): |
| return self._annotation |
| |
| @property |
| def kind(self): |
| return self._kind |
| |
| def replace(self, *, name=_void, kind=_void, annotation=_void, |
| default=_void, _partial_kwarg=_void): |
| '''Creates a customized copy of the Parameter.''' |
| |
| if name is _void: |
| name = self._name |
| |
| if kind is _void: |
| kind = self._kind |
| |
| if annotation is _void: |
| annotation = self._annotation |
| |
| if default is _void: |
| default = self._default |
| |
| if _partial_kwarg is _void: |
| _partial_kwarg = self._partial_kwarg |
| |
| return type(self)(name, kind, default=default, annotation=annotation, |
| _partial_kwarg=_partial_kwarg) |
| |
| def __str__(self): |
| kind = self.kind |
| |
| formatted = self._name |
| if kind == _POSITIONAL_ONLY: |
| if formatted is None: |
| formatted = '' |
| formatted = '<{}>'.format(formatted) |
| |
| # Add annotation and default value |
| if self._annotation is not _empty: |
| formatted = '{}:{}'.format(formatted, |
| formatannotation(self._annotation)) |
| |
| if self._default is not _empty: |
| formatted = '{}={}'.format(formatted, repr(self._default)) |
| |
| if kind == _VAR_POSITIONAL: |
| formatted = '*' + formatted |
| elif kind == _VAR_KEYWORD: |
| formatted = '**' + formatted |
| |
| return formatted |
| |
| def __repr__(self): |
| return '<{} at {:#x} {!r}>'.format(self.__class__.__name__, |
| id(self), self.name) |
| |
| def __eq__(self, other): |
| return (issubclass(other.__class__, Parameter) and |
| self._name == other._name and |
| self._kind == other._kind and |
| self._default == other._default and |
| self._annotation == other._annotation) |
| |
| def __ne__(self, other): |
| return not self.__eq__(other) |
| |
| |
| class BoundArguments: |
| '''Result of `Signature.bind` call. Holds the mapping of arguments |
| to the function's parameters. |
| |
| Has the following public attributes: |
| |
| * arguments : OrderedDict |
| An ordered mutable mapping of parameters' names to arguments' values. |
| Does not contain arguments' default values. |
| * signature : Signature |
| The Signature object that created this instance. |
| * args : tuple |
| Tuple of positional arguments values. |
| * kwargs : dict |
| Dict of keyword arguments values. |
| ''' |
| |
| def __init__(self, signature, arguments): |
| self.arguments = arguments |
| self._signature = signature |
| |
| @property |
| def signature(self): |
| return self._signature |
| |
| @property |
| def args(self): |
| args = [] |
| for param_name, param in self._signature.parameters.items(): |
| if (param.kind in (_VAR_KEYWORD, _KEYWORD_ONLY) or |
| param._partial_kwarg): |
| # Keyword arguments mapped by 'functools.partial' |
| # (Parameter._partial_kwarg is True) are mapped |
| # in 'BoundArguments.kwargs', along with VAR_KEYWORD & |
| # KEYWORD_ONLY |
| break |
| |
| try: |
| arg = self.arguments[param_name] |
| except KeyError: |
| # We're done here. Other arguments |
| # will be mapped in 'BoundArguments.kwargs' |
| break |
| else: |
| if param.kind == _VAR_POSITIONAL: |
| # *args |
| args.extend(arg) |
| else: |
| # plain argument |
| args.append(arg) |
| |
| return tuple(args) |
| |
| @property |
| def kwargs(self): |
| kwargs = {} |
| kwargs_started = False |
| for param_name, param in self._signature.parameters.items(): |
| if not kwargs_started: |
| if (param.kind in (_VAR_KEYWORD, _KEYWORD_ONLY) or |
| param._partial_kwarg): |
| kwargs_started = True |
| else: |
| if param_name not in self.arguments: |
| kwargs_started = True |
| continue |
| |
| if not kwargs_started: |
| continue |
| |
| try: |
| arg = self.arguments[param_name] |
| except KeyError: |
| pass |
| else: |
| if param.kind == _VAR_KEYWORD: |
| # **kwargs |
| kwargs.update(arg) |
| else: |
| # plain keyword argument |
| kwargs[param_name] = arg |
| |
| return kwargs |
| |
| def __eq__(self, other): |
| return (issubclass(other.__class__, BoundArguments) and |
| self.signature == other.signature and |
| self.arguments == other.arguments) |
| |
| def __ne__(self, other): |
| return not self.__eq__(other) |
| |
| |
| class Signature: |
| '''A Signature object represents the overall signature of a function. |
| It stores a Parameter object for each parameter accepted by the |
| function, as well as information specific to the function itself. |
| |
| A Signature object has the following public attributes and methods: |
| |
| * parameters : OrderedDict |
| An ordered mapping of parameters' names to the corresponding |
| Parameter objects (keyword-only arguments are in the same order |
| as listed in `code.co_varnames`). |
| * return_annotation : object |
| The annotation for the return type of the function if specified. |
| If the function has no annotation for its return type, this |
| attribute is not set. |
| * bind(*args, **kwargs) -> BoundArguments |
| Creates a mapping from positional and keyword arguments to |
| parameters. |
| * bind_partial(*args, **kwargs) -> BoundArguments |
| Creates a partial mapping from positional and keyword arguments |
| to parameters (simulating 'functools.partial' behavior.) |
| ''' |
| |
| __slots__ = ('_return_annotation', '_parameters') |
| |
| _parameter_cls = Parameter |
| _bound_arguments_cls = BoundArguments |
| |
| empty = _empty |
| |
| def __init__(self, parameters=None, *, return_annotation=_empty, |
| __validate_parameters__=True): |
| '''Constructs Signature from the given list of Parameter |
| objects and 'return_annotation'. All arguments are optional. |
| ''' |
| |
| if parameters is None: |
| params = OrderedDict() |
| else: |
| if __validate_parameters__: |
| params = OrderedDict() |
| top_kind = _POSITIONAL_ONLY |
| |
| for idx, param in enumerate(parameters): |
| kind = param.kind |
| if kind < top_kind: |
| msg = 'wrong parameter order: {} before {}' |
| msg = msg.format(top_kind, param.kind) |
| raise ValueError(msg) |
| else: |
| top_kind = kind |
| |
| name = param.name |
| if name is None: |
| name = str(idx) |
| param = param.replace(name=name) |
| |
| if name in params: |
| msg = 'duplicate parameter name: {!r}'.format(name) |
| raise ValueError(msg) |
| params[name] = param |
| else: |
| params = OrderedDict(((param.name, param) |
| for param in parameters)) |
| |
| self._parameters = types.MappingProxyType(params) |
| self._return_annotation = return_annotation |
| |
| @classmethod |
| def from_function(cls, func): |
| '''Constructs Signature for the given python function''' |
| |
| if not isinstance(func, types.FunctionType): |
| raise TypeError('{!r} is not a Python function'.format(func)) |
| |
| Parameter = cls._parameter_cls |
| |
| # Parameter information. |
| func_code = func.__code__ |
| pos_count = func_code.co_argcount |
| arg_names = func_code.co_varnames |
| positional = tuple(arg_names[:pos_count]) |
| keyword_only_count = func_code.co_kwonlyargcount |
| keyword_only = arg_names[pos_count:(pos_count + keyword_only_count)] |
| annotations = func.__annotations__ |
| defaults = func.__defaults__ |
| kwdefaults = func.__kwdefaults__ |
| |
| if defaults: |
| pos_default_count = len(defaults) |
| else: |
| pos_default_count = 0 |
| |
| parameters = [] |
| |
| # Non-keyword-only parameters w/o defaults. |
| non_default_count = pos_count - pos_default_count |
| for name in positional[:non_default_count]: |
| annotation = annotations.get(name, _empty) |
| parameters.append(Parameter(name, annotation=annotation, |
| kind=_POSITIONAL_OR_KEYWORD)) |
| |
| # ... w/ defaults. |
| for offset, name in enumerate(positional[non_default_count:]): |
| annotation = annotations.get(name, _empty) |
| parameters.append(Parameter(name, annotation=annotation, |
| kind=_POSITIONAL_OR_KEYWORD, |
| default=defaults[offset])) |
| |
| # *args |
| if func_code.co_flags & 0x04: |
| name = arg_names[pos_count + keyword_only_count] |
| annotation = annotations.get(name, _empty) |
| parameters.append(Parameter(name, annotation=annotation, |
| kind=_VAR_POSITIONAL)) |
| |
| # Keyword-only parameters. |
| for name in keyword_only: |
| default = _empty |
| if kwdefaults is not None: |
| default = kwdefaults.get(name, _empty) |
| |
| annotation = annotations.get(name, _empty) |
| parameters.append(Parameter(name, annotation=annotation, |
| kind=_KEYWORD_ONLY, |
| default=default)) |
| # **kwargs |
| if func_code.co_flags & 0x08: |
| index = pos_count + keyword_only_count |
| if func_code.co_flags & 0x04: |
| index += 1 |
| |
| name = arg_names[index] |
| annotation = annotations.get(name, _empty) |
| parameters.append(Parameter(name, annotation=annotation, |
| kind=_VAR_KEYWORD)) |
| |
| return cls(parameters, |
| return_annotation=annotations.get('return', _empty), |
| __validate_parameters__=False) |
| |
| @property |
| def parameters(self): |
| return self._parameters |
| |
| @property |
| def return_annotation(self): |
| return self._return_annotation |
| |
| def replace(self, *, parameters=_void, return_annotation=_void): |
| '''Creates a customized copy of the Signature. |
| Pass 'parameters' and/or 'return_annotation' arguments |
| to override them in the new copy. |
| ''' |
| |
| if parameters is _void: |
| parameters = self.parameters.values() |
| |
| if return_annotation is _void: |
| return_annotation = self._return_annotation |
| |
| return type(self)(parameters, |
| return_annotation=return_annotation) |
| |
| def __eq__(self, other): |
| if (not issubclass(type(other), Signature) or |
| self.return_annotation != other.return_annotation or |
| len(self.parameters) != len(other.parameters)): |
| return False |
| |
| other_positions = {param: idx |
| for idx, param in enumerate(other.parameters.keys())} |
| |
| for idx, (param_name, param) in enumerate(self.parameters.items()): |
| if param.kind == _KEYWORD_ONLY: |
| try: |
| other_param = other.parameters[param_name] |
| except KeyError: |
| return False |
| else: |
| if param != other_param: |
| return False |
| else: |
| try: |
| other_idx = other_positions[param_name] |
| except KeyError: |
| return False |
| else: |
| if (idx != other_idx or |
| param != other.parameters[param_name]): |
| return False |
| |
| return True |
| |
| def __ne__(self, other): |
| return not self.__eq__(other) |
| |
| def _bind(self, args, kwargs, *, partial=False): |
| '''Private method. Don't use directly.''' |
| |
| arguments = OrderedDict() |
| |
| parameters = iter(self.parameters.values()) |
| parameters_ex = () |
| arg_vals = iter(args) |
| |
| if partial: |
| # Support for binding arguments to 'functools.partial' objects. |
| # See 'functools.partial' case in 'signature()' implementation |
| # for details. |
| for param_name, param in self.parameters.items(): |
| if (param._partial_kwarg and param_name not in kwargs): |
| # Simulating 'functools.partial' behavior |
| kwargs[param_name] = param.default |
| |
| while True: |
| # Let's iterate through the positional arguments and corresponding |
| # parameters |
| try: |
| arg_val = next(arg_vals) |
| except StopIteration: |
| # No more positional arguments |
| try: |
| param = next(parameters) |
| except StopIteration: |
| # No more parameters. That's it. Just need to check that |
| # we have no `kwargs` after this while loop |
| break |
| else: |
| if param.kind == _VAR_POSITIONAL: |
| # That's OK, just empty *args. Let's start parsing |
| # kwargs |
| break |
| elif param.name in kwargs: |
| if param.kind == _POSITIONAL_ONLY: |
| msg = '{arg!r} parameter is positional only, ' \ |
| 'but was passed as a keyword' |
| msg = msg.format(arg=param.name) |
| raise TypeError(msg) from None |
| parameters_ex = (param,) |
| break |
| elif (param.kind == _VAR_KEYWORD or |
| param.default is not _empty): |
| # That's fine too - we have a default value for this |
| # parameter. So, lets start parsing `kwargs`, starting |
| # with the current parameter |
| parameters_ex = (param,) |
| break |
| else: |
| if partial: |
| parameters_ex = (param,) |
| break |
| else: |
| msg = '{arg!r} parameter lacking default value' |
| msg = msg.format(arg=param.name) |
| raise TypeError(msg) from None |
| else: |
| # We have a positional argument to process |
| try: |
| param = next(parameters) |
| except StopIteration: |
| raise TypeError('too many positional arguments') from None |
| else: |
| if param.kind in (_VAR_KEYWORD, _KEYWORD_ONLY): |
| # Looks like we have no parameter for this positional |
| # argument |
| raise TypeError('too many positional arguments') |
| |
| if param.kind == _VAR_POSITIONAL: |
| # We have an '*args'-like argument, let's fill it with |
| # all positional arguments we have left and move on to |
| # the next phase |
| values = [arg_val] |
| values.extend(arg_vals) |
| arguments[param.name] = tuple(values) |
| break |
| |
| if param.name in kwargs: |
| raise TypeError('multiple values for argument ' |
| '{arg!r}'.format(arg=param.name)) |
| |
| arguments[param.name] = arg_val |
| |
| # Now, we iterate through the remaining parameters to process |
| # keyword arguments |
| kwargs_param = None |
| for param in itertools.chain(parameters_ex, parameters): |
| if param.kind == _POSITIONAL_ONLY: |
| # This should never happen in case of a properly built |
| # Signature object (but let's have this check here |
| # to ensure correct behaviour just in case) |
| raise TypeError('{arg!r} parameter is positional only, ' |
| 'but was passed as a keyword'. \ |
| format(arg=param.name)) |
| |
| if param.kind == _VAR_KEYWORD: |
| # Memorize that we have a '**kwargs'-like parameter |
| kwargs_param = param |
| continue |
| |
| param_name = param.name |
| try: |
| arg_val = kwargs.pop(param_name) |
| except KeyError: |
| # We have no value for this parameter. It's fine though, |
| # if it has a default value, or it is an '*args'-like |
| # parameter, left alone by the processing of positional |
| # arguments. |
| if (not partial and param.kind != _VAR_POSITIONAL and |
| param.default is _empty): |
| raise TypeError('{arg!r} parameter lacking default value'. \ |
| format(arg=param_name)) from None |
| |
| else: |
| arguments[param_name] = arg_val |
| |
| if kwargs: |
| if kwargs_param is not None: |
| # Process our '**kwargs'-like parameter |
| arguments[kwargs_param.name] = kwargs |
| else: |
| raise TypeError('too many keyword arguments') |
| |
| return self._bound_arguments_cls(self, arguments) |
| |
| def bind(__bind_self, *args, **kwargs): |
| '''Get a BoundArguments object, that maps the passed `args` |
| and `kwargs` to the function's signature. Raises `TypeError` |
| if the passed arguments can not be bound. |
| ''' |
| return __bind_self._bind(args, kwargs) |
| |
| def bind_partial(__bind_self, *args, **kwargs): |
| '''Get a BoundArguments object, that partially maps the |
| passed `args` and `kwargs` to the function's signature. |
| Raises `TypeError` if the passed arguments can not be bound. |
| ''' |
| return __bind_self._bind(args, kwargs, partial=True) |
| |
| def __str__(self): |
| result = [] |
| render_kw_only_separator = True |
| for idx, param in enumerate(self.parameters.values()): |
| formatted = str(param) |
| |
| kind = param.kind |
| if kind == _VAR_POSITIONAL: |
| # OK, we have an '*args'-like parameter, so we won't need |
| # a '*' to separate keyword-only arguments |
| render_kw_only_separator = False |
| elif kind == _KEYWORD_ONLY and render_kw_only_separator: |
| # We have a keyword-only parameter to render and we haven't |
| # rendered an '*args'-like parameter before, so add a '*' |
| # separator to the parameters list ("foo(arg1, *, arg2)" case) |
| result.append('*') |
| # This condition should be only triggered once, so |
| # reset the flag |
| render_kw_only_separator = False |
| |
| result.append(formatted) |
| |
| rendered = '({})'.format(', '.join(result)) |
| |
| if self.return_annotation is not _empty: |
| anno = formatannotation(self.return_annotation) |
| rendered += ' -> {}'.format(anno) |
| |
| return rendered |