From: CF Bolz-Tereick <cfbolz@gmx.de>
Date: Fri, 27 Dec 2024 01:03:47 +0000 (+0100)
Subject: gh-127537: Add __class_getitem__ to the python implementation of functools.partial... 
X-Git-Tag: v3.14.0a4~186
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=401bba6b58497ce59e7b45ad33e43ae8c67abcb9;p=thirdparty%2FPython%2Fcpython.git

gh-127537: Add __class_getitem__ to the python implementation of functools.partial (#127537)
---

diff --git a/Lib/functools.py b/Lib/functools.py
index eff6540c7f60..786b8aedfd77 100644
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -433,6 +433,9 @@ class partial:
         self._phcount = phcount
         self._merger = merger
 
+    __class_getitem__ = classmethod(GenericAlias)
+
+
 try:
     from _functools import partial, Placeholder, _PlaceholderType
 except ImportError:
diff --git a/Lib/test/test_functools.py b/Lib/test/test_functools.py
index ffd2adb8665b..4a0252cb637a 100644
--- a/Lib/test/test_functools.py
+++ b/Lib/test/test_functools.py
@@ -473,6 +473,12 @@ class TestPartial:
         self.assertEqual(a.cmeth(3, b=4), ((1, A, 3), {'a': 2, 'b': 4}))
         self.assertEqual(a.smeth(3, b=4), ((1, 3), {'a': 2, 'b': 4}))
 
+    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):
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 000000000000..5e3993304799
--- /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.