bpo-42194: Add "New in version: 3.9" to argparse.BooleanOptionalAction (GH-23026...

(cherry picked from commit da2e673c53974641a0e13941950e7976bbda64d5)

Co-authored-by: David Sanders <shang.xiao.sanders@gmail.com>

diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst
index aa4713e75cd47188d26aed250c8e6553d389cc66..6c01667b961861893de9a47ac73f480e61aae4a4 100644 (file)
--- a/Doc/library/argparse.rst
+++ b/Doc/library/argparse.rst
@@ -853,6 +853,8 @@ is available in ``argparse`` and adds support for boolean actions such as
     >>> parser.parse_args(['--no-foo'])
     Namespace(foo=False)
 
+.. versionadded:: 3.9
+
 The recommended way to create a custom action is to extend :class:`Action`,
 overriding the ``__call__`` method and optionally the ``__init__`` and
 ``format_usage`` methods.