From: Shantanu <12621235+hauntsaninja@users.noreply.github.com>
Date: Fri, 27 Dec 2024 01:25:07 +0000 (-0800)
Subject: [3.12] gh-127537: Add __class_getitem__ to the python implementation of functools... 
X-Git-Tag: v3.12.9~133
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=82dbfbfec9e09b7cc63a8191e9068f13c04e31d8;p=thirdparty%2FPython%2Fcpython.git

[3.12] gh-127537: Add __class_getitem__ to the python implementation of functools.partial (#127537) (#128282)

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

(cherry picked from commit 401bba6b58497ce59e7b45ad33e43ae8c67abcb9)

Co-authored-by: CF Bolz-Tereick <cfbolz@gmx.de>
---

diff --git a/Lib/functools.py b/Lib/functools.py
index f6849899e757..6025032bfaa2 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 ff71fd53c08a..dadcd04394b3 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 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.