From f5162eaf78e69aad911391920c27ef2909339112 Mon Sep 17 00:00:00 2001
From: hongweipeng <hongweichen8888@sina.com>
Date: Thu, 9 Dec 2021 23:06:42 +0800
Subject: [PATCH] singledispatchmethod exposes registry and dispatch

---
 Doc/whatsnew/3.11.rst                                      | 7 +++++++
 Lib/functools.py                                           | 2 ++
 Lib/test/test_functools.py                                 | 7 +++++++
 .../next/Library/2021-12-09-23-00-06.bpo-42943.fVg5Bz.rst  | 2 ++
 4 files changed, 18 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Library/2021-12-09-23-00-06.bpo-42943.fVg5Bz.rst

diff --git a/Doc/whatsnew/3.11.rst b/Doc/whatsnew/3.11.rst
index 7a828663e7f34e..d7bc4086a4b634 100644
--- a/Doc/whatsnew/3.11.rst
+++ b/Doc/whatsnew/3.11.rst
@@ -213,6 +213,13 @@ fractions
   (Contributed by Mark Dickinson in :issue:`44547`.)
 
 
+functools
+---------
+
+* :class:`functools.singledispatchmethod` exposes members 'registry' and
+  'dispatch'. (Contributed by Weipeng Hong in :issue:`42943`.)
+
+
 inspect
 -------
 * Add :func:`inspect.getmembers_static`: return all members without
diff --git a/Lib/functools.py b/Lib/functools.py
index 77ec852805c104..5bda2b435c7482 100644
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -916,6 +916,8 @@ def _method(*args, **kwargs):
 
         _method.__isabstractmethod__ = self.__isabstractmethod__
         _method.register = self.register
+        _method.dispatch = self.dispatcher.dispatch
+        _method.registry = self.dispatcher.registry
         update_wrapper(_method, self.func)
         return _method
 
diff --git a/Lib/test/test_functools.py b/Lib/test/test_functools.py
index 08cf457cc17db5..39999b08133d4f 100644
--- a/Lib/test/test_functools.py
+++ b/Lib/test/test_functools.py
@@ -2371,6 +2371,13 @@ def _(self, arg):
         self.assertEqual(a.arg, "base")
         aa = A()
         self.assertFalse(hasattr(aa, 'arg'))
+        def fun(self, arg):
+            pass
+        A.t.register(list, fun)
+        self.assertIs(fun, A.t.dispatch(list))
+        self.assertIs(fun, A().t.dispatch(list))
+        self.assertIs(fun, A.t.registry[list])
+        self.assertIs(fun, A().t.registry[list])
 
     def test_staticmethod_register(self):
         class A:
diff --git a/Misc/NEWS.d/next/Library/2021-12-09-23-00-06.bpo-42943.fVg5Bz.rst b/Misc/NEWS.d/next/Library/2021-12-09-23-00-06.bpo-42943.fVg5Bz.rst
new file mode 100644
index 00000000000000..a492366a553670
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2021-12-09-23-00-06.bpo-42943.fVg5Bz.rst
@@ -0,0 +1,2 @@
+The :class:`functools.singledispatchmethod` exposes members 'registry' and
+'dispatch'. Patch by Weipeng Hong.