Issue #25137: Add a note to whatsnew/3.5.rst for nested functools.partial calls

Also, properly skip the test_nested_optimization test for partial subclasses
and add a test for the suggested usage.

1 files changed, 6 insertions, 0 deletions

diff --git a/Doc/whatsnew/3.5.rst b/Doc/whatsnew/3.5.rst
index 8c85b14..56cb00c 100644
--- a/Doc/whatsnew/3.5.rst
+++ b/Doc/whatsnew/3.5.rst
@@ -2441,6 +2441,12 @@ Changes in the Python API
   module and the :func:`help` function.
   (Contributed by Serhiy Storchaka in :issue:`15582`.)
 
+* Nested :func:`functools.partial` calls are now flattened.  If you were
+  relying on the previous behavior, you can now either add an attribute to a
+  :func:`functools.partial` object or you can create a subclass of
+  :func:`functools.partial`.
+  (Contributed by Alexander Belopolsky in :issue:`7830`.)
+
 Changes in the C API
 --------------------