| """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 |
| """ |
| |
| # 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 itertools |
| import string |
| import re |
| import imp |
| import tokenize |
| import linecache |
| from operator import attrgetter |
| from collections import namedtuple |
| |
| # Create constants for the compiler flags in Include/code.h |
| # We try to get them from dis to avoid duplication, but fall |
| # back to hardcording 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().""" |
| 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 |
| __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 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_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.""" |
| 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. |
| # Getting an obj from the __dict__ sometimes reveals more than |
| # using getattr. Static and class methods are dramatic examples. |
| if name in cls.__dict__: |
| obj = cls.__dict__[name] |
| else: |
| obj = getattr(cls, name) |
| |
| # Figure out where it was defined. |
| homecls = getattr(obj, "__objclass__", None) |
| if homecls is None: |
| # search the dicts. |
| for base in mro: |
| if name in base.__dict__: |
| homecls = base |
| break |
| |
| # Get the object again, in order to get it from the defining |
| # __dict__ instead of via getattr (if possible). |
| if homecls is not None and name in homecls.__dict__: |
| obj = homecls.__dict__[name] |
| |
| # Also get the object via getattr. |
| obj_via_getattr = getattr(cls, name) |
| |
| # Classify the object. |
| if isinstance(obj, staticmethod): |
| kind = "static method" |
| elif isinstance(obj, classmethod): |
| kind = "class method" |
| elif isinstance(obj, property): |
| kind = "property" |
| elif (isfunction(obj_via_getattr) or |
| ismethoddescriptor(obj_via_getattr)): |
| kind = "method" |
| else: |
| kind = "data" |
| |
| 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.""" |
| 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.""" |
| 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 filename[-4:].lower() in ('.pyc', '.pyo'): |
| filename = filename[:-4] + '.py' |
| for suffix, mode, kind in imp.get_suffixes(): |
| if 'b' in mode and filename[-len(suffix):].lower() == 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['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 = getsourcefile(object) |
| if not file: |
| raise IOError('source code not available') |
| 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] = [] |
| 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 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_total = num_pos + len(named) |
| num_args = len(args) |
| num_defaults = len(defaults) if defaults else 0 |
| for arg, value in zip(args, positional): |
| arg2value[arg] = value |
| if varargs: |
| if num_pos > num_args: |
| arg2value[varargs] = positional[-(num_pos-num_args):] |
| else: |
| arg2value[varargs] = () |
| elif 0 < num_args < num_pos: |
| raise TypeError('%s() takes %s %d positional %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: |
| raise TypeError('%s() takes no arguments (%d given)' % |
| (f_name, num_total)) |
| |
| for arg in itertools.chain(args, kwonlyargs): |
| if arg in named: |
| if arg in arg2value: |
| raise TypeError("%s() got multiple values for keyword " |
| "argument '%s'" % (f_name, arg)) |
| else: |
| arg2value[arg] = named.pop(arg) |
| for kwonlyarg in kwonlyargs: |
| if kwonlyarg not in arg2value: |
| try: |
| arg2value[kwonlyarg] = kwonlydefaults[kwonlyarg] |
| except KeyError: |
| raise TypeError("%s() needs keyword-only argument %s" % |
| (f_name, kwonlyarg)) |
| if defaults: # fill in any missing values with the defaults |
| for arg, value in zip(args[-num_defaults:], defaults): |
| if arg not in arg2value: |
| arg2value[arg] = value |
| if varkw: |
| arg2value[varkw] = named |
| elif named: |
| unexpected = next(iter(named)) |
| raise TypeError("%s() got an unexpected keyword argument '%s'" % |
| (f_name, unexpected)) |
| unassigned = num_args - len([arg for arg in args if arg in arg2value]) |
| 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 |
| |
| 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 instance_dict.get(attr, _sentinel) |
| |
| |
| def _check_class(klass, attr): |
| for entry in _static_getmro(klass): |
| 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 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): |
| instance_result = _check_instance(obj, attr) |
| klass = type(obj) |
| 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)): |
| try: |
| return entry.__dict__[attr] |
| except KeyError: |
| pass |
| if default is not _sentinel: |
| return default |
| raise AttributeError(attr) |
| |
| |
| GEN_CREATED, GEN_RUNNING, GEN_SUSPENDED, GEN_CLOSED = range(4) |
| |
| 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 |