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# encoding: utf-8
# The MIT License
#
# Copyright (c) 2009-2011 the bpython authors.
# Copyright (c) 2015 Sebastian Ramacher
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
from __future__ import absolute_import
import inspect
import io
import keyword
import pydoc
from collections import namedtuple
from six.moves import range
from pygments.token import Token
from types import MemberDescriptorType
from ._py3compat import PythonLexer, py3
from .lazyre import LazyReCompile
if not py3:
import types
_name = LazyReCompile(r"[a-zA-Z_]\w*$")
ArgSpec = namedtuple(
"ArgSpec",
[
"args",
"varargs",
"varkwargs",
"defaults",
"kwonly",
"kwonly_defaults",
"annotations",
],
)
FuncProps = namedtuple("FuncProps", ["func", "argspec", "is_bound_method"])
class AttrCleaner(object):
"""A context manager that tries to make an object not exhibit side-effects
on attribute lookup."""
def __init__(self, obj):
self.obj = obj
def __enter__(self):
"""Try to make an object not exhibit side-effects on attribute
lookup."""
type_ = type(self.obj)
__getattribute__ = None
__getattr__ = None
# Dark magic:
# If __getattribute__ doesn't exist on the class and __getattr__ does
# then __getattr__ will be called when doing
# getattr(type_, '__getattribute__', None)
# so we need to first remove the __getattr__, then the
# __getattribute__, then look up the attributes and then restore the
# original methods. :-(
# The upshot being that introspecting on an object to display its
# attributes will avoid unwanted side-effects.
if is_new_style(self.obj):
__getattr__ = getattr(type_, "__getattr__", None)
if __getattr__ is not None:
try:
setattr(type_, "__getattr__", (lambda *_, **__: None))
except TypeError:
__getattr__ = None
__getattribute__ = getattr(type_, "__getattribute__", None)
if __getattribute__ is not None:
try:
setattr(type_, "__getattribute__", object.__getattribute__)
except TypeError:
# XXX: This happens for e.g. built-in types
__getattribute__ = None
self.attribs = (__getattribute__, __getattr__)
# /Dark magic
def __exit__(self, exc_type, exc_val, exc_tb):
"""Restore an object's magic methods."""
type_ = type(self.obj)
__getattribute__, __getattr__ = self.attribs
# Dark magic:
if __getattribute__ is not None:
setattr(type_, "__getattribute__", __getattribute__)
if __getattr__ is not None:
setattr(type_, "__getattr__", __getattr__)
# /Dark magic
if py3:
def is_new_style(obj):
return True
else:
def is_new_style(obj):
"""Returns True if obj is a new-style class or object"""
return type(obj) not in [types.InstanceType, types.ClassType]
class _Repr(object):
"""
Helper for `fixlongargs()`: Returns the given value in `__repr__()`.
"""
def __init__(self, value):
self.value = value
def __repr__(self):
return self.value
__str__ = __repr__
def parsekeywordpairs(signature):
tokens = PythonLexer().get_tokens(signature)
preamble = True
stack = []
substack = []
parendepth = 0
for token, value in tokens:
if preamble:
if token is Token.Punctuation and value == u"(":
preamble = False
continue
if token is Token.Punctuation:
if value in [u"(", u"{", u"["]:
parendepth += 1
elif value in [u")", u"}", u"]"]:
parendepth -= 1
elif value == ":" and parendepth == -1:
# End of signature reached
break
if (value == "," and parendepth == 0) or (
value == ")" and parendepth == -1
):
stack.append(substack)
substack = []
continue
if value and (parendepth > 0 or value.strip()):
substack.append(value)
d = {}
for item in stack:
if len(item) >= 3:
d[item[0]] = "".join(item[2:])
return d
def fixlongargs(f, argspec):
"""Functions taking default arguments that are references to other objects
whose str() is too big will cause breakage, so we swap out the object
itself with the name it was referenced with in the source by parsing the
source itself !"""
if argspec[3] is None:
# No keyword args, no need to do anything
return
values = list(argspec[3])
if not values:
return
keys = argspec[0][-len(values) :]
try:
src = inspect.getsourcelines(f)
except (IOError, IndexError):
# IndexError is raised in inspect.findsource(), can happen in
# some situations. See issue #94.
return
signature = "".join(src[0])
kwparsed = parsekeywordpairs(signature)
for i, (key, value) in enumerate(zip(keys, values)):
if len(repr(value)) != len(kwparsed[key]):
values[i] = _Repr(kwparsed[key])
argspec[3] = values
getpydocspec_re = LazyReCompile(r"([a-zA-Z_][a-zA-Z0-9_]*?)\((.*?)\)")
def getpydocspec(f, func):
try:
argspec = pydoc.getdoc(f)
except NameError:
return None
s = getpydocspec_re.search(argspec)
if s is None:
return None
if not hasattr_safe(f, "__name__") or s.groups()[0] != f.__name__:
return None
args = list()
defaults = list()
varargs = varkwargs = None
kwonly_args = list()
kwonly_defaults = dict()
for arg in s.group(2).split(","):
arg = arg.strip()
if arg.startswith("**"):
varkwargs = arg[2:]
elif arg.startswith("*"):
varargs = arg[1:]
else:
arg, _, default = arg.partition("=")
if varargs is not None:
kwonly_args.append(arg)
if default:
kwonly_defaults[arg] = default
else:
args.append(arg)
if default:
defaults.append(default)
return ArgSpec(
args, varargs, varkwargs, defaults, kwonly_args, kwonly_defaults, None
)
def getfuncprops(func, f):
# Check if it's a real bound method or if it's implicitly calling __init__
# (i.e. FooClass(...) and not FooClass.__init__(...) -- the former would
# not take 'self', the latter would:
try:
func_name = getattr(f, "__name__", None)
except:
# if calling foo.__name__ would result in an error
func_name = None
try:
is_bound_method = (
(inspect.ismethod(f) and f.__self__ is not None)
or (func_name == "__init__" and not func.endswith(".__init__"))
or (func_name == "__new__" and not func.endswith(".__new__"))
)
except:
# if f is a method from a xmlrpclib.Server instance, func_name ==
# '__init__' throws xmlrpclib.Fault (see #202)
return None
try:
if py3:
argspec = get_argspec_from_signature(f)
else:
argspec = list(inspect.getargspec(f))
fixlongargs(f, argspec)
if len(argspec) == 4:
argspec = argspec + [list(), dict(), None]
argspec = ArgSpec(*argspec)
fprops = FuncProps(func, argspec, is_bound_method)
except (TypeError, KeyError, ValueError):
argspec = getpydocspec(f, func)
if argspec is None:
return None
if inspect.ismethoddescriptor(f):
argspec.args.insert(0, "obj")
fprops = FuncProps(func, argspec, is_bound_method)
return fprops
def is_eval_safe_name(string):
if py3:
return all(
part.isidentifier() and not keyword.iskeyword(part)
for part in string.split(".")
)
else:
return all(
_name.match(part) and not keyword.iskeyword(part)
for part in string.split(".")
)
def is_callable(obj):
return callable(obj)
def get_argspec_from_signature(f):
"""Get callable signature from inspect.signature in argspec format.
inspect.signature is a Python 3 only function that returns the signature of
a function. Its advantage over inspect.getfullargspec is that it returns
the signature of a decorated function, if the wrapper function itself is
decorated with functools.wraps.
"""
args = []
varargs = varkwargs = None
defaults = []
kwonly = []
kwonly_defaults = {}
annotations = {}
signature = inspect.signature(f)
for parameter in signature.parameters.values():
if parameter.annotation is not inspect._empty:
annotations[parameter.name] = parameter.annotation
if parameter.kind == inspect.Parameter.POSITIONAL_OR_KEYWORD:
args.append(parameter.name)
if parameter.default is not inspect._empty:
defaults.append(parameter.default)
elif parameter.kind == inspect.Parameter.POSITIONAL_ONLY:
args.append(parameter.name)
elif parameter.kind == inspect.Parameter.VAR_POSITIONAL:
varargs = parameter.name
elif parameter.kind == inspect.Parameter.KEYWORD_ONLY:
kwonly.append(parameter.name)
kwonly_defaults[parameter.name] = parameter.default
elif parameter.kind == inspect.Parameter.VAR_KEYWORD:
varkwargs = parameter.name
# inspect.getfullargspec returns None for 'defaults', 'kwonly_defaults' and
# 'annotations' if there are no values for them.
if not defaults:
defaults = None
if not kwonly_defaults:
kwonly_defaults = None
if not annotations:
annotations = None
return [
args,
varargs,
varkwargs,
defaults,
kwonly,
kwonly_defaults,
annotations,
]
get_encoding_line_re = LazyReCompile(r"^.*coding[:=]\s*([-\w.]+).*$")
def get_encoding(obj):
"""Try to obtain encoding information of the source of an object."""
for line in inspect.findsource(obj)[0][:2]:
m = get_encoding_line_re.search(line)
if m:
return m.group(1)
return "ascii"
def get_encoding_comment(source):
"""Returns encoding line without the newline, or None is not found"""
for line in source.splitlines()[:2]:
m = get_encoding_line_re.search(line)
if m:
return m.group(0)
return None
def get_encoding_file(fname):
"""Try to obtain encoding information from a Python source file."""
with io.open(fname, "rt", encoding="ascii", errors="ignore") as f:
for unused in range(2):
line = f.readline()
match = get_encoding_line_re.search(line)
if match:
return match.group(1)
return "ascii"
if not py3:
def getattr_safe(obj, name):
"""side effect free getattr"""
if not is_new_style(obj):
return getattr(obj, name)
with AttrCleaner(obj):
to_look_through = (
obj.__mro__
if inspect.isclass(obj)
else (obj,) + type(obj).__mro__
)
for cls in to_look_through:
if hasattr(cls, "__dict__") and name in cls.__dict__:
result = cls.__dict__[name]
if isinstance(result, MemberDescriptorType):
result = getattr(obj, name)
return result
raise AttributeError(name)
else:
def getattr_safe(obj, name):
"""side effect free getattr (calls getattr_static)."""
result = inspect.getattr_static(obj, name)
# Slots are a MemberDescriptorType
if isinstance(result, MemberDescriptorType):
result = getattr(obj, name)
return result
def hasattr_safe(obj, name):
try:
getattr_safe(obj, name)
return True
except AttributeError:
return False
if py3:
def get_source_unicode(obj):
"""Returns a decoded source of object"""
return inspect.getsource(obj)
else:
def get_source_unicode(obj):
"""Returns a decoded source of object"""
return inspect.getsource(obj).decode(get_encoding(obj))