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