diff --git a/Lib/functools.py b/Lib/functools.py index f6849899e75..6025032bfaa 100644 --- a/Lib/functools.py +++ b/Lib/functools.py @@ -340,6 +340,9 @@ class partial: self.args = args self.keywords = kwds + __class_getitem__ = classmethod(GenericAlias) + + try: from _functools import partial except ImportError: diff --git a/Lib/test/test_functools.py b/Lib/test/test_functools.py index ff71fd53c08..dadcd04394b 100644 --- a/Lib/test/test_functools.py +++ b/Lib/test/test_functools.py @@ -390,6 +390,13 @@ class TestPartial: f = self.partial(object) self.assertRaises(TypeError, f.__setstate__, BadSequence()) + def test_partial_genericalias(self): + alias = self.partial[int] + self.assertIs(alias.__origin__, self.partial) + self.assertEqual(alias.__args__, (int,)) + self.assertEqual(alias.__parameters__, ()) + + @unittest.skipUnless(c_functools, 'requires the C _functools module') class TestPartialC(TestPartial, unittest.TestCase): if c_functools: diff --git a/Misc/NEWS.d/next/Library/2024-12-04-10-39-29.gh-issue-83662.CG1s3m.rst b/Misc/NEWS.d/next/Library/2024-12-04-10-39-29.gh-issue-83662.CG1s3m.rst new file mode 100644 index 00000000000..5e399330479 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-12-04-10-39-29.gh-issue-83662.CG1s3m.rst @@ -0,0 +1,5 @@ +Add missing ``__class_getitem__`` method to the Python implementation of +:func:`functools.partial`, to make it compatible with the C version. This is +mainly relevant for alternative Python implementations like PyPy and +GraalPy, because CPython will usually use the C-implementation of that +function.