bpo-38531: document extend action's added version (GH-16865) (GH-16868)
(cherry picked from commit 74142078b3b78fea7b4cd791e5c577c0c0964eb7)
Co-authored-by: Batuhan Taşkaya <47358913+isidentical@users.noreply.github.com>
diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst
index ee005594..5a61a5b 100644
--- a/Doc/library/argparse.rst
+++ b/Doc/library/argparse.rst
@@ -810,6 +810,8 @@
>>> parser.parse_args(["--foo", "f1", "--foo", "f2", "f3", "f4"])
Namespace(foo=['f1', 'f2', 'f3', 'f4'])
+ .. versionadded:: 3.8
+
You may also specify an arbitrary action by passing an Action subclass or
other object that implements the same interface. The recommended way to do
this is to extend :class:`Action`, overriding the ``__call__`` method