From: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Date: Tue, 12 May 2026 02:53:36 +0000 (+0200) Subject: [3.14] gh-148669: Clarify `__reduce__()` module lookup behavior (GH-148670) (#149704) X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=49bf2d1cbd1ee3022dffed1af50c40b3a66238bb;p=thirdparty%2FPython%2Fcpython.git [3.14] gh-148669: Clarify `__reduce__()` module lookup behavior (GH-148670) (#149704) gh-148669: Clarify `__reduce__()` module lookup behavior (GH-148670) (cherry picked from commit 54a5fd4126df74f7b84d1f8a6a36ef79803f66f9) Co-authored-by: Victorien <65306057+Viicos@users.noreply.github.com> --- diff --git a/Doc/library/pickle.rst b/Doc/library/pickle.rst index 02b79a9f3a7a..efae4910ca43 100644 --- a/Doc/library/pickle.rst +++ b/Doc/library/pickle.rst @@ -59,7 +59,7 @@ The :mod:`!pickle` module differs from :mod:`marshal` in several significant way * :mod:`marshal` cannot be used to serialize user-defined classes and their instances. :mod:`!pickle` can save and restore class instances transparently, however the class definition must be importable and live in the same module as - when the object was stored. + when the object was pickled. * The :mod:`marshal` serialization format is not guaranteed to be portable across Python versions. Because its primary job in life is to support @@ -696,7 +696,10 @@ or both. If a string is returned, the string should be interpreted as the name of a global variable. It should be the object's local name relative to its module; the pickle module searches the module namespace to determine the - object's module. This behaviour is typically useful for singletons. + object's module: for a given ``obj`` to be pickled, the ``__module__`` + attribute is looked up on ``obj`` directly, which falls back to a lookup + on the type of ``obj`` if no ``__module__`` instance attribute is set. + This behaviour is typically useful for singletons. When a tuple is returned, it must be between two and six items long. Optional items can either be omitted, or ``None`` can be provided as their