From fda4f22d607f7c689a39755f3da673aaf26414e3 Mon Sep 17 00:00:00 2001
From: "Miss Islington (bot)"
 <31488909+miss-islington@users.noreply.github.com>
Date: Tue, 9 Jun 2026 17:46:39 +0200
Subject: [PATCH] [3.15] GH-61082: Clarify nargs='*' positional default
 behavior (GH-150989) (#151168)

GH-61082: Clarify nargs='*' positional default behavior (GH-150989)
(cherry picked from commit bc37a227b2f481d0f260f9beae5229e8d432a0cc)

Co-authored-by: Savannah Ostrowski <savannah@python.org>
---
 Doc/library/argparse.rst | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst
index 622f844a4a0..4c588d447a9 100644
--- a/Doc/library/argparse.rst
+++ b/Doc/library/argparse.rst
@@ -1051,6 +1051,10 @@ is used when no command-line argument was present::
    >>> parser.parse_args([])
    Namespace(foo=42)
 
+Because ``nargs='*'`` gathers any supplied values into a list, an absent
+positional argument yields an empty list (``[]``). Only a non-``None``
+*default* overrides this (so ``default=None`` still gives ``[]``).
+
 For required_ arguments, the ``default`` value is ignored. For example, this
 applies to positional arguments with nargs_ values other than ``?`` or ``*``,
 or optional arguments marked as ``required=True``.