python · serhiy-storchaka · Sep 29, 2024 · Sep 29, 2024
diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst
@@ -1774,7 +1774,7 @@ Sub-commands
     >>>
     >>> # create the parser for the "b" command
     >>> parser_b = subparsers.add_parser('b', help='b help')
-     >>> parser_b.add_argument('--baz', choices='XYZ', help='baz help')
+     >>> parser_b.add_argument('--baz', choices=('X', 'Y', 'Z'), help='baz help')
     >>>
     >>> # parse some argument lists
     >>> parser.parse_args(['a', '12'])

diff --git a/Lib/argparse.py b/Lib/argparse.py
@@ -2587,11 +2587,15 @@ def _get_value(self, action, arg_string):

    def _check_value(self, action, value):
        # converted value must be one of the choices (if specified)
-        if action.choices is not None and value not in action.choices:
-            args = {'value': value,
-                    'choices': ', '.join(map(repr, action.choices))}
-            msg = _('invalid choice: %(value)r (choose from %(choices)s)')
-            raise ArgumentError(action, msg % args)
+        choices = action.choices
+        if choices is not None:
+            if isinstance(choices, str):
+                choices = iter(choices)
+            if value not in choices:
+                args = {'value': value,
+                        'choices': ', '.join(map(repr, action.choices))}
+                msg = _('invalid choice: %(value)r (choose from %(choices)s)')
+                raise ArgumentError(action, msg % args)

    # =======================
    # Help-formatting methods

diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py
@@ -679,7 +679,7 @@ class TestOptionalsChoices(ParserTestCase):
    argument_signatures = [
        Sig('-f', choices='abc'),
        Sig('-g', type=int, choices=range(5))]
-    failures = ['a', '-f d', '-fad', '-ga', '-g 6']
+    failures = ['a', '-f d', '-f ab', '-fad', '-ga', '-g 6']
    successes = [
        ('', NS(f=None, g=None)),
        ('-f a', NS(f='a', g=None)),
@@ -2195,14 +2195,14 @@ def _get_parser(self, subparser_help=False, prefix_chars=None,
            parser1_kwargs['aliases'] = ['1alias1', '1alias2']
        parser1 = subparsers.add_parser('1', **parser1_kwargs)
        parser1.add_argument('-w', type=int, help='w help')
-        parser1.add_argument('x', choices='abc', help='x help')
+        parser1.add_argument('x', choices=['a', 'b', 'c'], help='x help')

        # add second sub-parser
        parser2_kwargs = dict(description='2 description')
        if subparser_help:
            parser2_kwargs['help'] = '2 help'
        parser2 = subparsers.add_parser('2', **parser2_kwargs)
-        parser2.add_argument('-y', choices='123', help='y help')
+        parser2.add_argument('-y', choices=['1', '2', '3'], help='y help')
        parser2.add_argument('z', type=complex, nargs='*', help='z help')

        # add third sub-parser
@@ -4365,7 +4365,7 @@ class TestHelpVariableExpansion(HelpTestCase):
            help='x %(prog)s %(default)s %(type)s %%'),
        Sig('-y', action='store_const', default=42, const='XXX',
            help='y %(prog)s %(default)s %(const)s'),
-        Sig('--foo', choices='abc',
+        Sig('--foo', choices=['a', 'b', 'c'],
            help='foo %(prog)s %(default)s %(choices)s'),
        Sig('--bar', default='baz', choices=[1, 2], metavar='BBB',
            help='bar %(prog)s %(default)s %(dest)s'),
@@ -5025,7 +5025,7 @@ def test_no_argument_actions(self):
        for action in ['store_const', 'store_true', 'store_false',
                       'append_const', 'count']:
            for attrs in [dict(type=int), dict(nargs='+'),
-                          dict(choices='ab')]:
+                          dict(choices=['a', 'b'])]:
                self.assertTypeError('-x', action=action, **attrs)

    def test_no_argument_no_const_actions(self):

diff --git a/Misc/NEWS.d/next/Library/2024-09-26-09-18-09.gh-issue-61181.dwjmch.rst b/Misc/NEWS.d/next/Library/2024-09-26-09-18-09.gh-issue-61181.dwjmch.rst
@@ -0,0 +1,2 @@
+Fix support of :ref:`choices` with string value in :mod:`argparse`. Substrings
+of the specified string no longer considered valid values.
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		Fix support of :ref:`choices` with string value in :mod:`argparse`. Substrings
		of the specified string no longer considered valid values.