diff --git a/Lib/argparse.py b/Lib/argparse.py index 9962e61a679..a999ea60614 100644 --- a/Lib/argparse.py +++ b/Lib/argparse.py @@ -2464,7 +2464,7 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer): # ======================== def _get_values(self, action, arg_strings): # for everything but PARSER, REMAINDER args, strip out first '--' - if action.nargs not in [PARSER, REMAINDER]: + if not action.option_strings and action.nargs not in [PARSER, REMAINDER]: try: arg_strings.remove('--') except ValueError: diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py index 6322ebbb840..adee4f3dc27 100644 --- a/Lib/test/test_argparse.py +++ b/Lib/test/test_argparse.py @@ -5272,6 +5272,23 @@ class TestParseKnownArgs(TestCase): self.assertEqual(NS(v=3, spam=True, badger="B"), args) self.assertEqual(["C", "--foo", "4"], extras) + def test_double_dash(self): + parser = argparse.ArgumentParser() + parser.add_argument('-f', '--foo', nargs='*') + parser.add_argument('bar', nargs='*') + + args = parser.parse_args(['--foo=--']) + self.assertEqual(NS(foo=['--'], bar=[]), args) + args = parser.parse_args(['--foo', '--']) + self.assertEqual(NS(foo=[], bar=[]), args) + args = parser.parse_args(['-f--']) + self.assertEqual(NS(foo=['--'], bar=[]), args) + args = parser.parse_args(['-f', '--']) + self.assertEqual(NS(foo=[], bar=[]), args) + args = parser.parse_args(['--foo', 'a', 'b', '--', 'c', 'd']) + self.assertEqual(NS(foo=['a', 'b'], bar=['c', 'd']), args) + + # =========================== # parse_intermixed_args tests # =========================== diff --git a/Misc/NEWS.d/next/Library/2024-01-31-20-07-11.gh-issue-109475.lmTb9S.rst b/Misc/NEWS.d/next/Library/2024-01-31-20-07-11.gh-issue-109475.lmTb9S.rst new file mode 100644 index 00000000000..7582cb2bcd7 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-01-31-20-07-11.gh-issue-109475.lmTb9S.rst @@ -0,0 +1,2 @@ +Fix support of explicit option value "--" in :mod:`argparse` (e.g. +``--option=--``).