diff --git a/Lib/argparse.py b/Lib/argparse.py index 9746173984c6ca..cc87700d56706e 100644 --- a/Lib/argparse.py +++ b/Lib/argparse.py @@ -863,6 +863,9 @@ def __init__(self, _option_strings.append(option_string) if option_string.startswith('--'): + if option_string.startswith('--no-'): + raise ValueError(f'invalid option name {option_string!r} ' + f'for BooleanOptionalAction') option_string = '--no-' + option_string[2:] _option_strings.append(option_string) diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py index ed1c5c34e526aa..5228b89338f197 100644 --- a/Lib/test/test_argparse.py +++ b/Lib/test/test_argparse.py @@ -782,6 +782,13 @@ def test_const(self): self.assertIn("got an unexpected keyword argument 'const'", str(cm.exception)) + def test_invalid_name(self): + parser = argparse.ArgumentParser() + with self.assertRaises(ValueError) as cm: + parser.add_argument('--no-foo', action=argparse.BooleanOptionalAction) + self.assertEqual(str(cm.exception), + "invalid option name '--no-foo' for BooleanOptionalAction") + class TestBooleanOptionalActionRequired(ParserTestCase): """Tests BooleanOptionalAction required""" diff --git a/Misc/NEWS.d/next/Library/2024-10-23-20-44-30.gh-issue-117941.Y9jdlW.rst b/Misc/NEWS.d/next/Library/2024-10-23-20-44-30.gh-issue-117941.Y9jdlW.rst new file mode 100644 index 00000000000000..f3099059e9db3f --- /dev/null +++ b/Misc/NEWS.d/next/Library/2024-10-23-20-44-30.gh-issue-117941.Y9jdlW.rst @@ -0,0 +1,2 @@ +:class:`argparse.BooleanOptionalAction` now rejects option names starting +with ``--no-``.