"""Get useful information from live Python objects.

This module encapsulates the interface provided by the internal special

attributes (co_*, im_*, tb_*, etc.) in a friendlier fashion.

It also provides some help for examining source code and class layout.

Here are some of the useful functions provided by this module:

ismodule(), isclass(), ismethod(), isfunction(), isgeneratorfunction(),

isgenerator(), istraceback(), isframe(), iscode(), isbuiltin(),

isroutine() - check object types

getmembers() - get members of an object that satisfy a given condition

getfile(), getsourcefile(), getsource() - find an object's source code

getdoc(), getcomments() - get documentation on an object

getmodule() - determine the module that an object came from

getclasstree() - arrange classes so as to represent their hierarchy

getargvalues(), getcallargs() - get info about function arguments

getfullargspec() - same, with support for Python 3 features

formatargvalues() - format an argument spec

getouterframes(), getinnerframes() - get info about frames

currentframe() - get the current stack frame

stack(), trace() - get info about frames on the stack or in a traceback

signature() - get a Signature object for the callable

"""

# This module is in the public domain. No warranties.

__author__ = ('Ka-Ping Yee <ping@lfw.org>',

'Yury Selivanov <yselivanov@sprymix.com>')

import abc

import dis

import collections.abc

import enum

import importlib.machinery

import itertools

import linecache

import os

import re

import sys

import tokenize

import token

import types

import warnings

import functools

import builtins

from operator import attrgetter

from collections import namedtuple, OrderedDict

# Create constants for the compiler flags in Include/code.h

# We try to get them from dis to avoid duplication

mod_dict = globals()

for k, v in dis.COMPILER_FLAG_NAMES.items():

mod_dict["CO_" + v] = k

# See Include/object.h

TPFLAGS_IS_ABSTRACT = 1 << 20

# ----------------------------------------------------------- type-checking

def ismodule(object):

"""Return true if the object is a module.

Module objects provide these attributes:

__cached__ pathname to byte compiled file

__doc__ documentation string

__file__ filename (missing for built-in modules)"""

return isinstance(object, types.ModuleType)

def isclass(object):

"""Return true if the object is a class.

Class objects provide these attributes:

__doc__ documentation string

__module__ name of module in which this class was defined"""

return isinstance(object, type)

def ismethod(object):

"""Return true if the object is an instance method.

Instance method objects provide these attributes:

__doc__ documentation string

__name__ name with which this method was defined

__func__ function object containing implementation of method

__self__ instance to which this method is bound"""

return isinstance(object, types.MethodType)

def ismethoddescriptor(object):

"""Return true if the object is a method descriptor.

But not if ismethod() or isclass() or isfunction() are true.

This is new in Python 2.2, and, for example, is true of int.__add__.

An object passing this test has a __get__ attribute but not a __set__

attribute, but beyond that the set of attributes varies. __name__ is

usually sensible, and __doc__ often is.

Methods implemented via descriptors that also pass one of the other

tests return false from the ismethoddescriptor() test, simply because

the other tests promise more -- you can, e.g., count on having the

__func__ attribute (etc) when an object passes ismethod()."""

if isclass(object) or ismethod(object) or isfunction(object):

# mutual exclusion

return False

tp = type(object)

return hasattr(tp, "__get__") and not hasattr(tp, "__set__")

def isdatadescriptor(object):

"""Return true if the object is a data descriptor.

Data descriptors have a __set__ or a __delete__ attribute. Examples are

properties (defined in Python) and getsets and members (defined in C).

Typically, data descriptors will also have __name__ and __doc__ attributes

(properties, getsets, and members have both of these attributes), but this

is not guaranteed."""

if isclass(object) or ismethod(object) or isfunction(object):

# mutual exclusion

return False

tp = type(object)

return hasattr(tp, "__set__") or hasattr(tp, "__delete__")

if hasattr(types, 'MemberDescriptorType'):

# CPython and equivalent

def ismemberdescriptor(object):

"""Return true if the object is a member descriptor.

Member descriptors are specialized descriptors defined in extension

modules."""

return isinstance(object, types.MemberDescriptorType)

else:

# Other implementations

def ismemberdescriptor(object):

"""Return true if the object is a member descriptor.

Member descriptors are specialized descriptors defined in extension

modules."""

return False

if hasattr(types, 'GetSetDescriptorType'):

# CPython and equivalent

def isgetsetdescriptor(object):

"""Return true if the object is a getset descriptor.

getset descriptors are specialized descriptors defined in extension

modules."""

return isinstance(object, types.GetSetDescriptorType)

else:

# Other implementations

def isgetsetdescriptor(object):

"""Return true if the object is a getset descriptor.

getset descriptors are specialized descriptors defined in extension

modules."""

return False

def isfunction(object):

"""Return true if the object is a user-defined function.

Function objects provide these attributes:

__doc__ documentation string

__name__ name with which this function was defined

__code__ code object containing compiled function bytecode

__defaults__ tuple of any default values for arguments

__globals__ global namespace in which this function was defined

__annotations__ dict of parameter annotations

__kwdefaults__ dict of keyword only parameters with defaults"""

return isinstance(object, types.FunctionType)

def _has_code_flag(f, flag):

"""Return true if ``f`` is a function (or a method or functools.partial

wrapper wrapping a function) whose code object has the given ``flag``

set in its flags."""

while ismethod(f):

f = f.__func__

f = functools._unwrap_partial(f)

if not isfunction(f):

return False

return bool(f.__code__.co_flags & flag)

def isgeneratorfunction(obj):

"""Return true if the object is a user-defined generator function.

Generator function objects provide the same attributes as functions.

See help(isfunction) for a list of attributes."""

return _has_code_flag(obj, CO_GENERATOR)

def iscoroutinefunction(obj):

"""Return true if the object is a coroutine function.

Coroutine functions are defined with "async def" syntax.

"""

return _has_code_flag(obj, CO_COROUTINE)

def isasyncgenfunction(obj):

"""Return true if the object is an asynchronous generator function.

Asynchronous generator functions are defined with "async def"

syntax and have "yield" expressions in their body.

"""

return _has_code_flag(obj, CO_ASYNC_GENERATOR)

def isasyncgen(object):

"""Return true if the object is an asynchronous generator."""

return isinstance(object, types.AsyncGeneratorType)

def isgenerator(object):

"""Return true if the object is a generator.

Generator objects provide these attributes:

__iter__ defined to support iteration over container

close raises a new GeneratorExit exception inside the

generator to terminate the iteration

gi_code code object

gi_frame frame object or possibly None once the generator has

been exhausted

gi_running set to 1 when generator is executing, 0 otherwise

next return the next item from the container

send resumes the generator and "sends" a value that becomes

the result of the current yield-expression

throw used to raise an exception inside the generator"""

return isinstance(object, types.GeneratorType)

def iscoroutine(object):

"""Return true if the object is a coroutine."""

return isinstance(object, types.CoroutineType)

def isawaitable(object):

"""Return true if object can be passed to an ``await`` expression."""

return (isinstance(object, types.CoroutineType) or

isinstance(object, types.GeneratorType) and

bool(object.gi_code.co_flags & CO_ITERABLE_COROUTINE) or

isinstance(object, collections.abc.Awaitable))

def istraceback(object):

"""Return true if the object is a traceback.

Traceback objects provide these attributes:

tb_frame frame object at this level

tb_lasti index of last attempted instruction in bytecode

tb_lineno current line number in Python source code

tb_next next inner traceback object (called by this level)"""

return isinstance(object, types.TracebackType)

def isframe(object):

"""Return true if the object is a frame object.

Frame objects provide these attributes:

f_back next outer frame object (this frame's caller)

f_builtins built-in namespace seen by this frame

f_code code object being executed in this frame

f_globals global namespace seen by this frame

f_lasti index of last attempted instruction in bytecode

f_lineno current line number in Python source code

f_locals local namespace seen by this frame

f_trace tracing function for this frame, or None"""

return isinstance(object, types.FrameType)

def iscode(object):

"""Return true if the object is a code object.

Code objects provide these attributes:

co_argcount number of arguments (not including *, ** args

or keyword only arguments)

co_code string of raw compiled bytecode

co_cellvars tuple of names of cell variables

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

| 16=nested | 32=generator | 64=nofree | 128=coroutine

| 256=iterable_coroutine | 512=async_generator

co_freevars tuple of names of free variables

co_posonlyargcount number of positional only arguments

co_kwonlyargcount number of keyword only arguments (not including ** 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)."""

if not isinstance(object, type):

return False

if object.__flags__ & TPFLAGS_IS_ABSTRACT:

return True

if not issubclass(type(object), abc.ABCMeta):

return False

if hasattr(object, '__abstractmethods__'):

# It looks like ABCMeta.__new__ has finished running;

# TPFLAGS_IS_ABSTRACT should have been accurate.

return False

# It looks like ABCMeta.__new__ has not finished running yet; we're

# probably in __init_subclass__. We'll look for abstractmethods manually.

for name, value in object.__dict__.items():

if getattr(value, "__isabstractmethod__", False):

return True

for base in object.__bases__:

for name in getattr(base, "__abstractmethods__", ()):

value = getattr(object, name, None)

if getattr(value, "__isabstractmethod__", False):

return True

return False

def getmembers(object, predicate=None):

"""Return all members of an object as (name, value) pairs sorted by name.

Optionally, only return members that satisfy a given predicate."""

if isclass(object):

mro = (object,) + getmro(object)

else:

mro = ()

results = []

processed = set()

names = dir(object)

# :dd any DynamicClassAttributes to the list of names if object is a class;

# this may result in duplicate entries if, for example, a virtual

# attribute with the same name as a DynamicClassAttribute exists

try:

for base in object.__bases__:

for k, v in base.__dict__.items():

if isinstance(v, types.DynamicClassAttribute):

names.append(k)

except AttributeError:

pass

for key in names:

# First try to get the value via getattr. Some descriptors don't

# like calling their __get__ (see bug #1785), so fall back to

# looking in the __dict__.

try:

value = getattr(object, key)

# handle the duplicate key

if key in processed:

raise AttributeError

except AttributeError:

for base in mro:

if key in base.__dict__:

value = base.__dict__[key]

break

else:

# could be a (currently) missing slot member, or a buggy

# __dir__; discard and move on

continue

if not predicate or predicate(value):

results.append((key, value))

processed.add(key)

results.sort(key=lambda pair: pair[0])

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 or descriptor

'data' not a method

2. The class which defined this attribute (a class).

3. The object as obtained by calling getattr; if this fails, or if the

resulting object does not live anywhere in the class' mro (including

metaclasses) then the object is looked up in the defining class's

dict (found by walking the mro).

If one of the items in dir(cls) is stored in the metaclass it will now

be discovered and not have None be listed as the class in which it was

defined. Any items whose home class cannot be discovered are skipped.

"""

mro = getmro(cls)

metamro = getmro(type(cls)) # for attributes stored in the metaclass

metamro = tuple(cls for cls in metamro if cls not in (type, object))

class_bases = (cls,) + mro

all_bases = class_bases + metamro

names = dir(cls)

# :dd any DynamicClassAttributes to the list of names;

# this may result in duplicate entries if, for example, a virtual

# attribute with the same name as a DynamicClassAttribute exists.

for base in mro:

for k, v in base.__dict__.items():

if isinstance(v, types.DynamicClassAttribute):

names.append(k)

result = []

processed = set()

for name in names:

# Get the object associated with the name, and where it was defined.

# Normal objects will be looked up with both getattr and directly in

# its class' dict (in case getattr fails [bug #1785], and also to look

# for a docstring).

# For DynamicClassAttributes on the second pass we only look in the

# class's dict.

#

# Getting an obj from the __dict__ sometimes reveals more than

# using getattr. Static and class methods are dramatic examples.

homecls = None

get_obj = None

dict_obj = None

if name not in processed:

try:

if name == '__dict__':

raise Exception("__dict__ is special, don't want the proxy")

get_obj = getattr(cls, name)

except Exception as exc:

pass

else:

homecls = getattr(get_obj, "__objclass__", homecls)

if homecls not in class_bases:

# if the resulting object does not live somewhere in the

# mro, drop it and search the mro manually

homecls = None

last_cls = None

# first look in the classes

for srch_cls in class_bases:

srch_obj = getattr(srch_cls, name, None)

if srch_obj is get_obj:

last_cls = srch_cls

# then check the metaclasses

for srch_cls in metamro:

try:

srch_obj = srch_cls.__getattr__(cls, name)

except AttributeError:

continue

if srch_obj is get_obj:

last_cls = srch_cls

if last_cls is not None:

homecls = last_cls

for base in all_bases:

if name in base.__dict__:

dict_obj = base.__dict__[name]

if homecls not in metamro:

homecls = base

break

if homecls is None:

# unable to locate the attribute anywhere, most likely due to

# buggy custom __dir__; discard and move on

continue

obj = get_obj if get_obj is not None else dict_obj

# Classify the object or its descriptor.

if isinstance(dict_obj, (staticmethod, types.BuiltinMethodType)):

kind = "static method"

obj = dict_obj

elif isinstance(dict_obj, (classmethod, types.ClassMethodDescriptorType)):

kind = "class method"

obj = dict_obj

elif isinstance(dict_obj, property):

kind = "property"

obj = dict_obj

elif isroutine(obj):

kind = "method"

else:

kind = "data"

result.append(Attribute(name, kind, homecls, obj))

processed.add(name)

return result

# ----------------------------------------------------------- class helpers

def getmro(cls):

"Return tuple of base classes (including cls) in method resolution order."

return cls.__mro__

# -------------------------------------------------------- function helpers

def unwrap(func, *, stop=None):

"""Get the object wrapped by *func*.

Follows the chain of :attr:`__wrapped__` attributes returning the last

object in the chain.

*stop* is an optional callback accepting an object in the wrapper chain

as its sole argument that allows the unwrapping to be terminated early if

the callback returns a true value. If the callback never returns a true

value, the last object in the chain is returned as usual. For example,

:func:`signature` uses this to stop unwrapping if any object in the

chain has a ``__signature__`` attribute defined.

:exc:`ValueError` is raised if a cycle is encountered.

"""

if stop is None:

def _is_wrapper(f):

return hasattr(f, '__wrapped__')

else:

def _is_wrapper(f):

return hasattr(f, '__wrapped__') and not stop(f)

f = func # remember the original func for error reporting

# Memoise by id to tolerate non-hashable objects, but store objects to

# ensure they aren't destroyed, which would allow their IDs to be reused.

memo = {id(f): f}

recursion_limit = sys.getrecursionlimit()

while _is_wrapper(func):

func = func.__wrapped__

id_func = id(func)

if (id_func in memo) or (len(memo) >= recursion_limit):

raise ValueError('wrapper loop when unwrapping {!r}'.format(f))

memo[id_func] = func

return func

# -------------------------------------------------- source code extraction

def indentsize(line):

"""Return the indent size, in spaces, at the start of a line of text."""

expline = line.expandtabs()

return len(expline) - len(expline.lstrip())

def _findclass(func):

cls = sys.modules.get(func.__module__)

if cls is None:

return None

for name in func.__qualname__.split('.')[:-1]:

cls = getattr(cls, name)

if not isclass(cls):

return None

return cls

def _finddoc(obj):

if isclass(obj):

for base in obj.__mro__:

if base is not object:

try:

doc = base.__doc__

except AttributeError:

continue

if doc is not None:

return doc

return None

if ismethod(obj):

name = obj.__func__.__name__

self = obj.__self__

if (isclass(self) and

getattr(getattr(self, name, None), '__func__') is obj.__func__):

# classmethod

cls = self

else:

cls = self.__class__

elif isfunction(obj):

name = obj.__name__

cls = _findclass(obj)

if cls is None or getattr(cls, name) is not obj:

return None

elif isbuiltin(obj):

name = obj.__name__

self = obj.__self__

if (isclass(self) and

self.__qualname__ + '.' + name == obj.__qualname__):

# classmethod

cls = self

else:

cls = self.__class__

# Should be tested before isdatadescriptor().

elif isinstance(obj, property):

func = obj.fget

name = func.__name__

cls = _findclass(func)

if cls is None or getattr(cls, name) is not obj:

return None

elif ismethoddescriptor(obj) or isdatadescriptor(obj):

name = obj.__name__

cls = obj.__objclass__

if getattr(cls, name) is not obj:

return None

if ismemberdescriptor(obj):

slots = getattr(cls, '__slots__', None)

if isinstance(slots, dict) and name in slots:

return slots[name]

else:

return None

for base in cls.__mro__:

try:

doc = getattr(base, name).__doc__

except AttributeError:

continue

if doc is not None:

return doc

return None

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 doc is None:

try:

doc = _finddoc(object)

except (AttributeError, TypeError):

return None

if not isinstance(doc, str):

return None

return cleandoc(doc)

def cleandoc(doc):

"""Clean up indentation from docstrings.

Any whitespace that can be uniformly removed from the second line

onwards is removed."""

try:

lines = doc.expandtabs().split('\n')

except UnicodeError:

return None

else:

# Find minimum indentation of any non-blank lines after first line.

margin = sys.maxsize

for line in lines[1:]:

content = len(line.lstrip())

if content:

indent = len(line) - content

margin = min(margin, indent)

# Remove indentation.

if lines:

lines[0] = lines[0].lstrip()

if margin < sys.maxsize:

for i in range(1, len(lines)): lines[i] = lines[i][margin:]

# Remove any trailing or leading blank lines.

while lines and not lines[-1]:

lines.pop()

while lines and not lines[0]:

lines.pop(0)

return '\n'.join(lines)

def getfile(object):

"""Work out which source or compiled file an object was defined in."""

if ismodule(object):

if getattr(object, '__file__', None):

return object.__file__

raise TypeError('{!r} is a built-in module'.format(object))

if isclass(object):

if hasattr(object, '__module__'):

module = sys.modules.get(object.__module__)

if getattr(module, '__file__', None):

return module.__file__

raise TypeError('{!r} is a built-in class'.format(object))

if ismethod(object):

object = object.__func__

if isfunction(object):

object = object.__code__

if istraceback(object):

object = object.tb_frame

if isframe(object):

object = object.f_code

if iscode(object):

return object.co_filename

raise TypeError('module, class, method, function, traceback, frame, or '

'code object was expected, got {}'.format(

type(object).__name__))

def getmodulename(path):

"""Return the module name for a given file, or None."""

fname = os.path.basename(path)

# Check for paths that look like an actual module file

suffixes = [(-len(suffix), suffix)

for suffix in importlib.machinery.all_suffixes()]

suffixes.sort() # try longest suffixes first, in case they overlap

for neglen, suffix in suffixes:

if fname.endswith(suffix):

return fname[:neglen]

return None

def getsourcefile(object):

"""Return the filename that can be used to locate an object's source.

Return None if no way can be identified to get the source.

"""

filename = getfile(object)

all_bytecode_suffixes = importlib.machinery.DEBUG_BYTECODE_SUFFIXES[:]

all_bytecode_suffixes += importlib.machinery.OPTIMIZED_BYTECODE_SUFFIXES[:]

if any(filename.endswith(s) for s in all_bytecode_suffixes):

filename = (os.path.splitext(filename)[0] +

importlib.machinery.SOURCE_SUFFIXES[0])

elif any(filename.endswith(s) for s in

importlib.machinery.EXTENSION_SUFFIXES):

return None

if os.path.exists(filename):

return filename

# only return a non-existent filename if the module has a PEP 302 loader

if getattr(getmodule(object, filename), '__loader__', None) is not None:

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.copy().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 OSError

is raised if the source code cannot be retrieved."""

file = getsourcefile(object)

if file:

# Invalidate cache if needed.

linecache.checkcache(file)

else:

file = getfile(object)

# Allow filenames in form of "<something>" to pass through.

# `doctest` monkeypatches `linecache` module to enable

# inspection, so let `linecache.getlines` to be called.

if not (file.startswith('<') and file.endswith('>')):

raise OSError('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 OSError('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 OSError('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 OSError('could not find function definition')

lnum = object.co_firstlineno - 1

pat = re.compile(r'^(\s*def\s)|(\s*async\s+def\s)|(.*(?<!\w)lambda(:|\s))|^(\s*@)')

while lnum > 0:

try:

line = lines[lnum]

except IndexError:

raise OSError('lineno is out of bounds')

if pat.match(line):

break

lnum = lnum - 1

return lines, lnum

raise OSError('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 (OSError, 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.indecorator = False

self.decoratorhasargs = False

self.last = 1

self.body_col0 = None

def tokeneater(self, type, token, srowcol, erowcol, line):

if not self.started and not self.indecorator:

# skip any decorators

if token == "@":

self.indecorator = True

# look for the first "def", "class" or "lambda"

elif 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 token == "(":

if self.indecorator:

self.decoratorhasargs = True

elif token == ")":

if self.indecorator:

self.indecorator = False

self.decoratorhasargs = False

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

# hitting a NEWLINE when in a decorator without args

# ends the decorator

if self.indecorator and not self.decoratorhasargs:

self.indecorator = False

elif self.passline:

pass

elif type == tokenize.INDENT:

if self.body_col0 is None and self.started:

self.body_col0 = erowcol[1]

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 type == tokenize.COMMENT:

if self.body_col0 is not None and srowcol[1] >= self.body_col0:

# Include comments if indented at least as much as the block

self.last = srowcol[0]

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 OSError is

raised if the source code cannot be retrieved."""

object = unwrap(object)

lines, lnum = findsource(object)

if istraceback(object):

object = object.tb_frame

# for module or frame that corresponds to module, return all source lines

if (ismodule(object) or

(isframe(object) and object.f_code.co_name == "<module>")):

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

OSError is raised if the source code cannot be retrieved."""

lines, lnum = getsourcelines(object)

return ''.join(lines)

# --------------------------------------------------- class tree extraction