8000 Support PEP 612 in typing_extensions (Python 3) (#774) · python/typing@c23141f · GitHub
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Support PEP 612 in typing_extensions (Python 3) (#774)
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‎typing_extensions/README.rst

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@@ -50,6 +50,7 @@ All Python versions:
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- ``Text``
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- ``Type``
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- ``TypedDict``
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- ``TypeAlias``
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- ``TYPE_CHECKING``
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Python 3.4+ only:
@@ -82,6 +83,12 @@ subclass ``typing.Reversible`` as of Python 3.5.3.
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These changes are _not_ backported to prevent subtle compatibility
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issues when mixing the differing implementations of modified classes.
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Certain types have incorrect runtime behavior due to limitations of older
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versions of the typing module. For example, ``ParamSpec`` and ``Concatenate``
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will not work with ``get_args``, ``get_origin`` or user-defined ``Generic``\ s
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because they need to be lists to work with older versions of ``Callable``.
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These types are only guaranteed to work for static type checking.
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Running tests
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=============
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‎typing_extensions/src_py3/test_typing_extensions.py

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@@ -13,7 +13,8 @@
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from typing import Generic
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from typing import no_type_check
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from typing_extensions import NoReturn, ClassVar, Final, IntVar, Literal, Type, NewType, TypedDict
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from typing_extensions import TypeAlias
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from typing_extensions import TypeAlias, ParamSpec, Concatenate
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try:
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from typing_extensions import Protocol, runtime, runtime_checkable
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except ImportError:
@@ -1898,6 +1899,118 @@ def test_cannot_subscript(self):
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with self.assertRaises(TypeError):
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TypeAlias[int]
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class ParamSpecTests(BaseTestCase):
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def test_basic_plain(self):
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P = ParamSpec('P')
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self.assertEqual(P, P)
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self.assertIsInstance(P, ParamSpec)
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# Should be hashable
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hash(P)
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def test_repr(self):
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P = ParamSpec('P')
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P_co = ParamSpec('P_co', covariant=True)
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P_contra = ParamSpec('P_contra', contravariant=True)
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P_2 = ParamSpec('P_2')
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self.assertEqual(repr(P), '~P')
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self.assertEqual(repr(P_2), '~P_2')
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# Note: PEP 612 doesn't require these to be repr-ed correctly, but
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# just follow CPython.
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self.assertEqual(repr(P_co), '+P_co')
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self.assertEqual(repr(P_contra), '-P_contra')
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def test_valid_uses(self):
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P = ParamSpec('P')
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T = TypeVar('T')
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C1 = typing.Callable[P, int]
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C2 = typing.Callable[P, T]
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# Note: no tests for Callable.__args__ and Callable.__parameters__ here
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# because pre-3.10 Callable sees ParamSpec as a plain list, not a
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# TypeVar.
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# Test collections.abc.Callable too.
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if sys.version_info[:2] >= (3, 9):
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C3 = collections.abc.Callable[P, int]
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C4 = collections.abc.Callable[P, T]
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# ParamSpec instances should also have args and kwargs attributes.
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self.assertIn('args', dir(P))
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self.assertIn('kwargs', dir(P))
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P.args
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P.kwargs
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# Note: ParamSpec doesn't work for pre-3.10 user-defined Generics due
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# to type checks inside Generic.
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def test_pickle(self):
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global P, P_co, P_contra
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P = ParamSpec('P')
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P_co = ParamSpec('P_co', covariant=True)
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P_contra = ParamSpec('P_contra', contravariant=True)
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for proto in range(pickle.HIGHEST_PROTOCOL):
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with self.subTest('Pickle protocol {proto}'.format(proto=proto)):
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for paramspec in (P, P_co, P_contra):
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z = pickle.loads(pickle.dumps(paramspec, proto))
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self.assertEqual(z.__name__, paramspec.__name__)
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self.assertEqual(z.__covariant__, paramspec.__covariant__)
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self.assertEqual(z.__contravariant__, paramspec.__contravariant__)
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self.assertEqual(z.__bound__, paramspec.__bound__)
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def test_eq(self):
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P = ParamSpec('P')
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self.assertEqual(P, P)
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self.assertEqual(hash(P), hash(P))
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# ParamSpec should compare by id similar to TypeVar in CPython
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self.assertNotEqual(ParamSpec('P'), P)
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self.assertIsNot(ParamSpec('P'), P)
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# Note: normally you don't test this as it breaks when there's
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# a hash collision. However, ParamSpec *must* guarantee that
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# as long as two objects don't have the same ID, their hashes
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# won't be the same.
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self.assertNotEqual(hash(ParamSpec('P')), hash(P))
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class ConcatenateTests(BaseTestCase):
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def test_basics(self):
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P = ParamSpec('P')
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class MyClass: ...
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c = Concatenate[MyClass, P]
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self.assertNotEqual(c, Concatenate)
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def test_valid_uses(self):
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P = ParamSpec('P')
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T = TypeVar('T')
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C1 = typing.Callable[Concatenate[int, P], int]
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C2 = typing.Callable[Concatenate[int, T, P], T]
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# Test collections.abc.Callable too.
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if sys.version_info[:2] >= (3, 9):
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C3 = collections.abc.Callable[Concatenate[int, P], int]
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C4 = collections.abc.Callable[Concatenate[int, T, P], T]
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def test_basic_introspection(self):
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P = ParamSpec('P')
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C1 = Concatenate[int, P]
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C2 = Concatenate[int, T, P]
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self.assertEqual(C1.__origin__, Concatenate)
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self.assertEqual(C1.__args__, (int, P))
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self.assertEqual(C2.__origin__, Concatenate)
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self.assertEqual(C2.__args__, (int, T, P))
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def test_eq(self):
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P = ParamSpec('P')
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C1 = Concatenate[int, P]
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C2 = Concatenate[int, P]
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C3 = Concatenate[int, T, P]
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self.assertEqual(C1, C2)
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self.assertEqual(hash(C1), hash(C2))
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self.assertNotEqual(C1, C3)
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class AllTests(BaseTestCase):
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@@ -1914,6 +2027,10 @@ def test_typing_extensions_includes_standard(self):
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self.assertIn('overload', a)
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self.assertIn('Text', a)
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self.assertIn('TYPE_CHECKING', a)
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self.assertIn('TypeAlias', a)
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self.assertIn('ParamSpec', a)
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self.assertIn("Concatenate", a)
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if TYPING_3_5_3:
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self.assertIn('Annotated', a)
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if PEP_560:

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