Vehicle-Anti-Theft-Face-Rec.../venv/Lib/site-packages/jedi/inference/compiled/getattr_static.py

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2020-11-12 16:05:57 +00:00
"""
A static version of getattr.
This is a backport of the Python 3 code with a little bit of additional
information returned to enable Jedi to make decisions.
"""
import types
from jedi import debug
from jedi._compatibility import py_version
_sentinel = object()
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_newstyle(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 _static_getmro_newstyle(klass):
mro = type.__dict__['__mro__'].__get__(klass)
if not isinstance(mro, (tuple, list)):
# There are unfortunately no tests for this, I was not able to
# reproduce this in pure Python. However should still solve the issue
# raised in GH #1517.
debug.warning('mro of %s returned %s, should be a tuple' % (klass, mro))
return ()
return mro
if py_version >= 30:
_shadowed_dict = _shadowed_dict_newstyle
_get_type = type
_static_getmro = _static_getmro_newstyle
else:
def _shadowed_dict(klass):
"""
In Python 2 __dict__ is not overwritable:
class Foo(object): pass
setattr(Foo, '__dict__', 4)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: __dict__ must be a dictionary object
It applies to both newstyle and oldstyle classes:
class Foo(object): pass
setattr(Foo, '__dict__', 4)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: attribute '__dict__' of 'type' objects is not writable
It also applies to instances of those objects. However to keep things
straight forward, newstyle classes always use the complicated way of
accessing it while oldstyle classes just use getattr.
"""
if type(klass) is _oldstyle_class_type:
return getattr(klass, '__dict__', _sentinel)
return _shadowed_dict_newstyle(klass)
class _OldStyleClass:
pass
_oldstyle_instance_type = type(_OldStyleClass())
_oldstyle_class_type = type(_OldStyleClass)
def _get_type(obj):
type_ = object.__getattribute__(obj, '__class__')
if type_ is _oldstyle_instance_type:
# Somehow for old style classes we need to access it directly.
return obj.__class__
return type_
def _static_getmro(klass):
if type(klass) is _oldstyle_class_type:
def oldstyle_mro(klass):
"""
Oldstyle mro is a really simplistic way of look up mro:
https://stackoverflow.com/questions/54867/what-is-the-difference-between-old-style-and-new-style-classes-in-python
"""
yield klass
for base in klass.__bases__:
for yield_from in oldstyle_mro(base):
yield yield_from
return oldstyle_mro(klass)
return _static_getmro_newstyle(klass)
def _safe_hasattr(obj, name):
return _check_class(_get_type(obj), name) is not _sentinel
def _safe_is_data_descriptor(obj):
return _safe_hasattr(obj, '__set__') or _safe_hasattr(obj, '__delete__')
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.
Returns a tuple `(attr, is_get_descriptor)`. is_get_descripter means that
the attribute is a descriptor that has a `__get__` attribute.
"""
instance_result = _sentinel
if not _is_type(obj):
klass = _get_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 _safe_hasattr(klass_result, '__get__') \
and _safe_is_data_descriptor(klass_result):
# A get/set descriptor has priority over everything.
return klass_result, True
if instance_result is not _sentinel:
return instance_result, False
if klass_result is not _sentinel:
return klass_result, _safe_hasattr(klass_result, '__get__')
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], False
except KeyError:
pass
if default is not _sentinel:
return default, False
raise AttributeError(attr)