[Python-checkins] gh-89828: Do not relay the __class__ attribute in GenericAlias (#93754)
serhiy-storchaka
webhook-mailer at python.org
Sat Jun 18 04:35:06 EDT 2022
https://github.com/python/cpython/commit/f9433fff476aa13af9cb314fcc6962055faa4085
commit: f9433fff476aa13af9cb314fcc6962055faa4085
branch: main
author: Serhiy Storchaka <storchaka at gmail.com>
committer: serhiy-storchaka <storchaka at gmail.com>
date: 2022-06-18T11:34:57+03:00
summary:
gh-89828: Do not relay the __class__ attribute in GenericAlias (#93754)
list[int].__class__ returned type, and isinstance(list[int], type)
returned True. It caused numerous problems in code that checks
isinstance(x, type).
files:
A Misc/NEWS.d/next/Core and Builtins/2022-06-12-19-31-56.gh-issue-89828.bq02M7.rst
M Lib/dataclasses.py
M Lib/functools.py
M Lib/pydoc.py
M Lib/types.py
M Lib/typing.py
M Objects/genericaliasobject.c
diff --git a/Lib/dataclasses.py b/Lib/dataclasses.py
index 18ab69053fd52..69cab8c563ea9 100644
--- a/Lib/dataclasses.py
+++ b/Lib/dataclasses.py
@@ -230,7 +230,7 @@ def __init__(self, type):
self.type = type
def __repr__(self):
- if isinstance(self.type, type) and not isinstance(self.type, GenericAlias):
+ if isinstance(self.type, type):
type_name = self.type.__name__
else:
# typing objects, e.g. List[int]
@@ -1248,7 +1248,7 @@ def _is_dataclass_instance(obj):
def is_dataclass(obj):
"""Returns True if obj is a dataclass or an instance of a
dataclass."""
- cls = obj if isinstance(obj, type) and not isinstance(obj, GenericAlias) else type(obj)
+ cls = obj if isinstance(obj, type) else type(obj)
return hasattr(cls, _FIELDS)
diff --git a/Lib/functools.py b/Lib/functools.py
index cd5666dfa71fd..43ead512e1ea4 100644
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -843,12 +843,11 @@ def _is_union_type(cls):
return get_origin(cls) in {Union, types.UnionType}
def _is_valid_dispatch_type(cls):
- if isinstance(cls, type) and not isinstance(cls, GenericAlias):
+ if isinstance(cls, type):
return True
from typing import get_args
return (_is_union_type(cls) and
- all(isinstance(arg, type) and not isinstance(arg, GenericAlias)
- for arg in get_args(cls)))
+ all(isinstance(arg, type) for arg in get_args(cls)))
def register(cls, func=None):
"""generic_func.register(cls, func) -> func
diff --git a/Lib/pydoc.py b/Lib/pydoc.py
index cec9ac89f1cc8..e96cacbe43445 100755
--- a/Lib/pydoc.py
+++ b/Lib/pydoc.py
@@ -70,7 +70,6 @@ class or function within a module or module in a package. If the
import sysconfig
import time
import tokenize
-import types
import urllib.parse
import warnings
from collections import deque
@@ -92,16 +91,13 @@ def pathdirs():
normdirs.append(normdir)
return dirs
-def _isclass(object):
- return inspect.isclass(object) and not isinstance(object, types.GenericAlias)
-
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):
+ if not inspect.isclass(cls):
return None
return cls
@@ -109,7 +105,7 @@ def _finddoc(obj):
if inspect.ismethod(obj):
name = obj.__func__.__name__
self = obj.__self__
- if (_isclass(self) and
+ if (inspect.isclass(self) and
getattr(getattr(self, name, None), '__func__') is obj.__func__):
# classmethod
cls = self
@@ -123,7 +119,7 @@ def _finddoc(obj):
elif inspect.isbuiltin(obj):
name = obj.__name__
self = obj.__self__
- if (_isclass(self) and
+ if (inspect.isclass(self) and
self.__qualname__ + '.' + name == obj.__qualname__):
# classmethod
cls = self
@@ -210,7 +206,7 @@ def classname(object, modname):
def isdata(object):
"""Check if an object is of a type that probably means it's data."""
- return not (inspect.ismodule(object) or _isclass(object) or
+ return not (inspect.ismodule(object) or inspect.isclass(object) or
inspect.isroutine(object) or inspect.isframe(object) or
inspect.istraceback(object) or inspect.iscode(object))
@@ -481,7 +477,7 @@ def document(self, object, name=None, *args):
# by lacking a __name__ attribute) and an instance.
try:
if inspect.ismodule(object): return self.docmodule(*args)
- if _isclass(object): return self.docclass(*args)
+ if inspect.isclass(object): return self.docclass(*args)
if inspect.isroutine(object): return self.docroutine(*args)
except AttributeError:
pass
@@ -783,7 +779,7 @@ def docmodule(self, object, name=None, mod=None, *ignored):
modules = inspect.getmembers(object, inspect.ismodule)
classes, cdict = [], {}
- for key, value in inspect.getmembers(object, _isclass):
+ for key, value in inspect.getmembers(object, inspect.isclass):
# if __all__ exists, believe it. Otherwise use old heuristic.
if (all is not None or
(inspect.getmodule(value) or object) is object):
@@ -1223,7 +1219,7 @@ def docmodule(self, object, name=None, mod=None):
result = result + self.section('DESCRIPTION', desc)
classes = []
- for key, value in inspect.getmembers(object, _isclass):
+ for key, value in inspect.getmembers(object, inspect.isclass):
# if __all__ exists, believe it. Otherwise use old heuristic.
if (all is not None
or (inspect.getmodule(value) or object) is object):
@@ -1707,7 +1703,7 @@ def describe(thing):
return 'member descriptor %s.%s.%s' % (
thing.__objclass__.__module__, thing.__objclass__.__name__,
thing.__name__)
- if _isclass(thing):
+ if inspect.isclass(thing):
return 'class ' + thing.__name__
if inspect.isfunction(thing):
return 'function ' + thing.__name__
@@ -1768,7 +1764,7 @@ def render_doc(thing, title='Python Library Documentation: %s', forceload=0,
desc += ' in module ' + module.__name__
if not (inspect.ismodule(object) or
- _isclass(object) or
+ inspect.isclass(object) or
inspect.isroutine(object) or
inspect.isdatadescriptor(object) or
_getdoc(object)):
diff --git a/Lib/types.py b/Lib/types.py
index 9490da7b9ee3b..2e73fbc450133 100644
--- a/Lib/types.py
+++ b/Lib/types.py
@@ -80,7 +80,7 @@ def resolve_bases(bases):
updated = False
shift = 0
for i, base in enumerate(bases):
- if isinstance(base, type) and not isinstance(base, GenericAlias):
+ if isinstance(base, type):
continue
if not hasattr(base, "__mro_entries__"):
continue
diff --git a/Lib/typing.py b/Lib/typing.py
index 25cae7ffb8d78..1ebc3ce1f64bd 100644
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -1079,7 +1079,7 @@ def __typing_prepare_subst__(self, alias, args):
var_tuple_index = None
fillarg = None
for k, arg in enumerate(args):
- if not (isinstance(arg, type) and not isinstance(arg, GenericAlias)):
+ if not isinstance(arg, type):
subargs = getattr(arg, '__typing_unpacked_tuple_args__', None)
if subargs and len(subargs) == 2 and subargs[-1] is ...:
if var_tuple_index is not None:
diff --git a/Misc/NEWS.d/next/Core and Builtins/2022-06-12-19-31-56.gh-issue-89828.bq02M7.rst b/Misc/NEWS.d/next/Core and Builtins/2022-06-12-19-31-56.gh-issue-89828.bq02M7.rst
new file mode 100644
index 0000000000000..14ca99e1458ce
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2022-06-12-19-31-56.gh-issue-89828.bq02M7.rst
@@ -0,0 +1,2 @@
+:class:`types.GenericAlias` no longer relays the ``__class__`` attribute.
+For example, ``isinstance(list[int], type)`` no longer returns ``True``.
diff --git a/Objects/genericaliasobject.c b/Objects/genericaliasobject.c
index 0a0d0cc4c15b6..b2636d5475dbb 100644
--- a/Objects/genericaliasobject.c
+++ b/Objects/genericaliasobject.c
@@ -583,6 +583,7 @@ ga_vectorcall(PyObject *self, PyObject *const *args,
}
static const char* const attr_exceptions[] = {
+ "__class__",
"__origin__",
"__args__",
"__unpacked__",
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