bpo-38531: document extend action's added version (GH-16865) (GH-16868)

miss-islington · isidentical · rhettinger · commit db385229645d · 2019-10-20T13:25:25.000-07:00
(cherry picked from commit 7414207) Co-authored-by: Batuhan Taşkaya <47358913+isidentical@users.noreply.github.com>
diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst
@@ -810,6 +810,8 @@ how the command-line arguments should be handled. The supplied actions are:
     >>> 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
