From: Savannah Ostrowski <savannah@python.org>
Date: Tue, 9 Jun 2026 15:37:24 +0000 (-0700)
Subject: GH-61082: Clarify nargs='*' positional default behavior (#150989)
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=bc37a227b2f481d0f260f9beae5229e8d432a0cc;p=thirdparty%2FPython%2Fcpython.git

GH-61082: Clarify nargs='*' positional default behavior (#150989)
---

diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst
index 622f844a4a0b..4c588d447a9a 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``.