2074 lines
77 KiB
Python
2074 lines
77 KiB
Python
"""Get useful information from live Python objects.
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This module encapsulates the interface provided by the internal special
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attributes (co_*, im_*, tb_*, etc.) in a friendlier fashion.
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It also provides some help for examining source code and class layout.
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Here are some of the useful functions provided by this module:
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ismodule(), isclass(), ismethod(), isfunction(), isgeneratorfunction(),
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isgenerator(), istraceback(), isframe(), iscode(), isbuiltin(),
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isroutine() - check object types
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getmembers() - get members of an object that satisfy a given condition
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getfile(), getsourcefile(), getsource() - find an object's source code
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getdoc(), getcomments() - get documentation on an object
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getmodule() - determine the module that an object came from
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getclasstree() - arrange classes so as to represent their hierarchy
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getargspec(), getargvalues(), getcallargs() - get info about function arguments
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getfullargspec() - same, with support for Python-3000 features
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formatargspec(), formatargvalues() - format an argument spec
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getouterframes(), getinnerframes() - get info about frames
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currentframe() - get the current stack frame
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stack(), trace() - get info about frames on the stack or in a traceback
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signature() - get a Signature object for the callable
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"""
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# This module is in the public domain. No warranties.
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__author__ = ('Ka-Ping Yee <ping@lfw.org>',
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'Yury Selivanov <yselivanov@sprymix.com>')
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import imp
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import importlib.machinery
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import itertools
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import linecache
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import os
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import re
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import sys
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import tokenize
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import types
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import warnings
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import functools
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import builtins
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from operator import attrgetter
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from collections import namedtuple, OrderedDict
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# Create constants for the compiler flags in Include/code.h
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# We try to get them from dis to avoid duplication, but fall
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# back to hardcording so the dependency is optional
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try:
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from dis import COMPILER_FLAG_NAMES as _flag_names
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except ImportError:
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CO_OPTIMIZED, CO_NEWLOCALS = 0x1, 0x2
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CO_VARARGS, CO_VARKEYWORDS = 0x4, 0x8
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CO_NESTED, CO_GENERATOR, CO_NOFREE = 0x10, 0x20, 0x40
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else:
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mod_dict = globals()
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for k, v in _flag_names.items():
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mod_dict["CO_" + v] = k
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# See Include/object.h
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TPFLAGS_IS_ABSTRACT = 1 << 20
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# ----------------------------------------------------------- type-checking
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def ismodule(object):
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"""Return true if the object is a module.
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Module objects provide these attributes:
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__cached__ pathname to byte compiled file
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__doc__ documentation string
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__file__ filename (missing for built-in modules)"""
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return isinstance(object, types.ModuleType)
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def isclass(object):
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"""Return true if the object is a class.
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Class objects provide these attributes:
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__doc__ documentation string
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__module__ name of module in which this class was defined"""
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return isinstance(object, type)
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def ismethod(object):
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"""Return true if the object is an instance method.
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Instance method objects provide these attributes:
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__doc__ documentation string
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__name__ name with which this method was defined
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__func__ function object containing implementation of method
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__self__ instance to which this method is bound"""
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return isinstance(object, types.MethodType)
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def ismethoddescriptor(object):
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"""Return true if the object is a method descriptor.
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But not if ismethod() or isclass() or isfunction() are true.
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This is new in Python 2.2, and, for example, is true of int.__add__.
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An object passing this test has a __get__ attribute but not a __set__
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attribute, but beyond that the set of attributes varies. __name__ is
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usually sensible, and __doc__ often is.
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Methods implemented via descriptors that also pass one of the other
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tests return false from the ismethoddescriptor() test, simply because
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the other tests promise more -- you can, e.g., count on having the
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__func__ attribute (etc) when an object passes ismethod()."""
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if isclass(object) or ismethod(object) or isfunction(object):
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# mutual exclusion
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return False
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tp = type(object)
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return hasattr(tp, "__get__") and not hasattr(tp, "__set__")
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def isdatadescriptor(object):
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"""Return true if the object is a data descriptor.
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Data descriptors have both a __get__ and a __set__ attribute. Examples are
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properties (defined in Python) and getsets and members (defined in C).
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Typically, data descriptors will also have __name__ and __doc__ attributes
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(properties, getsets, and members have both of these attributes), but this
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is not guaranteed."""
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if isclass(object) or ismethod(object) or isfunction(object):
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# mutual exclusion
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return False
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tp = type(object)
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return hasattr(tp, "__set__") and hasattr(tp, "__get__")
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if hasattr(types, 'MemberDescriptorType'):
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# CPython and equivalent
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def ismemberdescriptor(object):
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"""Return true if the object is a member descriptor.
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Member descriptors are specialized descriptors defined in extension
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modules."""
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return isinstance(object, types.MemberDescriptorType)
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else:
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# Other implementations
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def ismemberdescriptor(object):
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"""Return true if the object is a member descriptor.
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Member descriptors are specialized descriptors defined in extension
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modules."""
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return False
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if hasattr(types, 'GetSetDescriptorType'):
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# CPython and equivalent
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def isgetsetdescriptor(object):
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"""Return true if the object is a getset descriptor.
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getset descriptors are specialized descriptors defined in extension
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modules."""
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return isinstance(object, types.GetSetDescriptorType)
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else:
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# Other implementations
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def isgetsetdescriptor(object):
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"""Return true if the object is a getset descriptor.
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getset descriptors are specialized descriptors defined in extension
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modules."""
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return False
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def isfunction(object):
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"""Return true if the object is a user-defined function.
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Function objects provide these attributes:
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__doc__ documentation string
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__name__ name with which this function was defined
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__code__ code object containing compiled function bytecode
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__defaults__ tuple of any default values for arguments
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__globals__ global namespace in which this function was defined
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__annotations__ dict of parameter annotations
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__kwdefaults__ dict of keyword only parameters with defaults"""
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return isinstance(object, types.FunctionType)
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def isgeneratorfunction(object):
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"""Return true if the object is a user-defined generator function.
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Generator function objects provides same attributes as functions.
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See help(isfunction) for attributes listing."""
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return bool((isfunction(object) or ismethod(object)) and
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object.__code__.co_flags & CO_GENERATOR)
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def isgenerator(object):
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"""Return true if the object is a generator.
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Generator objects provide these attributes:
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__iter__ defined to support interation over container
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close raises a new GeneratorExit exception inside the
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generator to terminate the iteration
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gi_code code object
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gi_frame frame object or possibly None once the generator has
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been exhausted
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gi_running set to 1 when generator is executing, 0 otherwise
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next return the next item from the container
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send resumes the generator and "sends" a value that becomes
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the result of the current yield-expression
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throw used to raise an exception inside the generator"""
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return isinstance(object, types.GeneratorType)
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def istraceback(object):
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"""Return true if the object is a traceback.
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Traceback objects provide these attributes:
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tb_frame frame object at this level
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tb_lasti index of last attempted instruction in bytecode
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tb_lineno current line number in Python source code
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tb_next next inner traceback object (called by this level)"""
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return isinstance(object, types.TracebackType)
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def isframe(object):
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"""Return true if the object is a frame object.
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Frame objects provide these attributes:
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f_back next outer frame object (this frame's caller)
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f_builtins built-in namespace seen by this frame
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f_code code object being executed in this frame
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f_globals global namespace seen by this frame
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f_lasti index of last attempted instruction in bytecode
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f_lineno current line number in Python source code
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f_locals local namespace seen by this frame
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f_trace tracing function for this frame, or None"""
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return isinstance(object, types.FrameType)
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def iscode(object):
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"""Return true if the object is a code object.
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Code objects provide these attributes:
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co_argcount number of arguments (not including * or ** args)
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co_code string of raw compiled bytecode
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co_consts tuple of constants used in the bytecode
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co_filename name of file in which this code object was created
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co_firstlineno number of first line in Python source code
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co_flags bitmap: 1=optimized | 2=newlocals | 4=*arg | 8=**arg
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co_lnotab encoded mapping of line numbers to bytecode indices
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co_name name with which this code object was defined
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co_names tuple of names of local variables
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co_nlocals number of local variables
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co_stacksize virtual machine stack space required
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co_varnames tuple of names of arguments and local variables"""
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return isinstance(object, types.CodeType)
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def isbuiltin(object):
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"""Return true if the object is a built-in function or method.
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Built-in functions and methods provide these attributes:
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__doc__ documentation string
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__name__ original name of this function or method
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__self__ instance to which a method is bound, or None"""
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return isinstance(object, types.BuiltinFunctionType)
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def isroutine(object):
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"""Return true if the object is any kind of function or method."""
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return (isbuiltin(object)
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or isfunction(object)
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or ismethod(object)
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or ismethoddescriptor(object))
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def isabstract(object):
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"""Return true if the object is an abstract base class (ABC)."""
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return bool(isinstance(object, type) and object.__flags__ & TPFLAGS_IS_ABSTRACT)
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def getmembers(object, predicate=None):
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"""Return all members of an object as (name, value) pairs sorted by name.
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Optionally, only return members that satisfy a given predicate."""
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if isclass(object):
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mro = (object,) + getmro(object)
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else:
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mro = ()
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results = []
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for key in dir(object):
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# First try to get the value via __dict__. Some descriptors don't
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# like calling their __get__ (see bug #1785).
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for base in mro:
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if key in base.__dict__:
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value = base.__dict__[key]
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break
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else:
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try:
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value = getattr(object, key)
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except AttributeError:
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continue
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if not predicate or predicate(value):
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results.append((key, value))
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results.sort()
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return results
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Attribute = namedtuple('Attribute', 'name kind defining_class object')
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def classify_class_attrs(cls):
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"""Return list of attribute-descriptor tuples.
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For each name in dir(cls), the return list contains a 4-tuple
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with these elements:
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0. The name (a string).
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1. The kind of attribute this is, one of these strings:
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'class method' created via classmethod()
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'static method' created via staticmethod()
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'property' created via property()
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'method' any other flavor of method
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'data' not a method
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2. The class which defined this attribute (a class).
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3. The object as obtained directly from the defining class's
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__dict__, not via getattr. This is especially important for
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data attributes: C.data is just a data object, but
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C.__dict__['data'] may be a data descriptor with additional
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info, like a __doc__ string.
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"""
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mro = getmro(cls)
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names = dir(cls)
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result = []
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for name in names:
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# Get the object associated with the name, and where it was defined.
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# Getting an obj from the __dict__ sometimes reveals more than
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# using getattr. Static and class methods are dramatic examples.
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# Furthermore, some objects may raise an Exception when fetched with
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# getattr(). This is the case with some descriptors (bug #1785).
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# Thus, we only use getattr() as a last resort.
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homecls = None
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for base in (cls,) + mro:
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if name in base.__dict__:
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obj = base.__dict__[name]
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homecls = base
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break
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else:
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obj = getattr(cls, name)
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homecls = getattr(obj, "__objclass__", homecls)
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# Classify the object.
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if isinstance(obj, staticmethod):
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kind = "static method"
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elif isinstance(obj, classmethod):
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kind = "class method"
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elif isinstance(obj, property):
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kind = "property"
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elif ismethoddescriptor(obj):
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kind = "method"
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elif isdatadescriptor(obj):
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kind = "data"
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else:
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obj_via_getattr = getattr(cls, name)
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if (isfunction(obj_via_getattr) or
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ismethoddescriptor(obj_via_getattr)):
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kind = "method"
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else:
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kind = "data"
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obj = obj_via_getattr
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result.append(Attribute(name, kind, homecls, obj))
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return result
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# ----------------------------------------------------------- class helpers
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def getmro(cls):
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"Return tuple of base classes (including cls) in method resolution order."
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return cls.__mro__
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# -------------------------------------------------- source code extraction
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def indentsize(line):
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"""Return the indent size, in spaces, at the start of a line of text."""
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expline = line.expandtabs()
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return len(expline) - len(expline.lstrip())
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def getdoc(object):
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"""Get the documentation string for an object.
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All tabs are expanded to spaces. To clean up docstrings that are
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indented to line up with blocks of code, any whitespace than can be
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uniformly removed from the second line onwards is removed."""
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try:
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doc = object.__doc__
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except AttributeError:
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return None
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if not isinstance(doc, str):
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return None
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return cleandoc(doc)
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def cleandoc(doc):
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"""Clean up indentation from docstrings.
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Any whitespace that can be uniformly removed from the second line
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onwards is removed."""
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try:
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lines = doc.expandtabs().split('\n')
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except UnicodeError:
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return None
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else:
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# Find minimum indentation of any non-blank lines after first line.
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margin = sys.maxsize
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for line in lines[1:]:
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content = len(line.lstrip())
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if content:
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indent = len(line) - content
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margin = min(margin, indent)
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# Remove indentation.
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if lines:
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lines[0] = lines[0].lstrip()
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if margin < sys.maxsize:
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for i in range(1, len(lines)): lines[i] = lines[i][margin:]
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# Remove any trailing or leading blank lines.
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while lines and not lines[-1]:
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lines.pop()
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while lines and not lines[0]:
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lines.pop(0)
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return '\n'.join(lines)
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def getfile(object):
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"""Work out which source or compiled file an object was defined in."""
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if ismodule(object):
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if hasattr(object, '__file__'):
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return object.__file__
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raise TypeError('{!r} is a built-in module'.format(object))
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if isclass(object):
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object = sys.modules.get(object.__module__)
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if hasattr(object, '__file__'):
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return object.__file__
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raise TypeError('{!r} is a built-in class'.format(object))
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if ismethod(object):
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object = object.__func__
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if isfunction(object):
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object = object.__code__
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if istraceback(object):
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object = object.tb_frame
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if isframe(object):
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object = object.f_code
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if iscode(object):
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return object.co_filename
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raise TypeError('{!r} is not a module, class, method, '
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'function, traceback, frame, or code object'.format(object))
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ModuleInfo = namedtuple('ModuleInfo', 'name suffix mode module_type')
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def getmoduleinfo(path):
|
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"""Get the module name, suffix, mode, and module type for a given file."""
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warnings.warn('inspect.getmoduleinfo() is deprecated', DeprecationWarning,
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2)
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filename = os.path.basename(path)
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suffixes = [(-len(suffix), suffix, mode, mtype)
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for suffix, mode, mtype in imp.get_suffixes()]
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suffixes.sort() # try longest suffixes first, in case they overlap
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for neglen, suffix, mode, mtype in suffixes:
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if filename[neglen:] == suffix:
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return ModuleInfo(filename[:neglen], suffix, mode, mtype)
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|
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def getmodulename(path):
|
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"""Return the module name for a given file, or None."""
|
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fname = os.path.basename(path)
|
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# Check for paths that look like an actual module file
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suffixes = [(-len(suffix), suffix)
|
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for suffix in importlib.machinery.all_suffixes()]
|
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suffixes.sort() # try longest suffixes first, in case they overlap
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for neglen, suffix in suffixes:
|
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if fname.endswith(suffix):
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return fname[:neglen]
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return None
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|
|
|
def getsourcefile(object):
|
|
"""Return the filename that can be used to locate an object's source.
|
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Return None if no way can be identified to get the source.
|
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"""
|
|
filename = getfile(object)
|
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all_bytecode_suffixes = importlib.machinery.DEBUG_BYTECODE_SUFFIXES[:]
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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] +
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importlib.machinery.SOURCE_SUFFIXES[0])
|
|
elif any(filename.endswith(s) for s in
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importlib.machinery.EXTENSION_SUFFIXES):
|
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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__'):
|
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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[0] + 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] = []
|
|
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(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 self._bind(args, kwargs)
|
|
|
|
def bind_partial(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 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
|