Nov 25, 2022 · Nov 25, 2022 · Nov 25, 2022 · Nov 25, 2022 · Nov 25, 2022 · Nov 25, 2022
diff --git a/Lib/argparse.py b/Lib/argparse.py
    'ZERO_OR_MORE',
 ]


 import difflib as _difflib
 import os as _os
 import re as _re
 import sys as _sys
        return result

    def _check_value(self, action, value):
        if not action.choices and isinstance(action.choices, list):
            msg = 'Either add options in choices array or remove it'
            raise ArgumentError(action, msg)

        # 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)')
            try:
                closest_choice = _difflib.get_close_matches(value, action.choices, 1)
            except TypeError:
                closest_choice = []

            args = {
                'value': value,
                'choices': ', '.join(map(repr, action.choices)),
            }
            if closest_choice:
                closest_choice = closest_choice[0]
                args['closest'] = closest_choice
                msg = _('invalid choice: %(value)r, maybe you meant %(closest)r? '
                        '(choose from %(choices)s)')
            else:
                msg = _('invalid choice: %(value)r (choose from %(choices)s)')

            raise ArgumentError(action, msg % args)

    # =======================
diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py
        subparsers.add_parser('bar')
        with self.assertRaises(ArgumentParserError) as excinfo:
            parser.parse_args(('baz',))
        self.assertRegex(
        self.assertIn(
            "error: argument {foo,bar}: invalid choice: 'baz', maybe you meant 'bar'? (choose from 'foo', 'bar')",
            excinfo.exception.stderr,
            r"error: argument {foo,bar}: invalid choice: 'baz' \(choose from 'foo', 'bar'\)\n$"
        )

    def test_optional_subparsers(self):
diff --git a/Misc/NEWS.d/next/Core and Builtins/2022-11-25-12-23-56.gh-issue-99749.-S_guS.rst b/Misc/NEWS.d/next/Core and Builtins/2022-11-25-12-23-56.gh-issue-99749.-S_guS.rst
 Add closest choice if exists in Argparser if wrong choice picked.
Original file line number	Diff line number	Diff line change
Expand Up		@@ -84,7 +84,7 @@
		'ZERO_OR_MORE',
		]


		import difflib as _difflib
Copy link Member savannahostrowskiSep 23, 2024 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. I think we'd probably want to move the import down into the case where the error is thrown, since this is probably not going to be used very often.
		import os as _os
		import re as _re
		import sys as _sys
Expand DownExpand Up		@@ -2541,11 +2541,29 @@ def _get_value(self, action, arg_string):
		return result

		def _check_value(self, action, value):
		if not action.choices and isinstance(action.choices, list):
		msg = 'Either add options in choices array or remove it'
		raise ArgumentError(action, msg)

		# 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)')
		try:
		closest_choice = _difflib.get_close_matches(value, action.choices, 1)
		except TypeError:
		closest_choice = []

		args = {
		'value': value,
		'choices': ', '.join(map(repr, action.choices)),
		}
		if closest_choice:
		closest_choice = closest_choice[0]
		args['closest'] = closest_choice
		msg = _('invalid choice: %(value)r, maybe you meant %(closest)r? '
		'(choose from %(choices)s)')
		else:
		msg = _('invalid choice: %(value)r (choose from %(choices)s)')

		raise ArgumentError(action, msg % args)

		# =======================
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -2193,9 +2193,9 @@ def test_wrong_argument_subparsers_no_destination_error(self):
		subparsers.add_parser('bar')
		with self.assertRaises(ArgumentParserError) as excinfo:
		parser.parse_args(('baz',))
		self.assertRegex(
		self.assertIn(
Copy link Member savannahostrowskiSep 23, 2024 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. We probably also want some additional test cases here.
		"error: argument {foo,bar}: invalid choice: 'baz', maybe you meant 'bar'? (choose from 'foo', 'bar')",
Copy link Member savannahostrowskiSep 23, 2024 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. I'd be interested in others' opinions around the verbiage here. It seems like we are using both "Maybe you meant" and "Did you mean" verbiage in the codebase. Not sure if we have any principle around this.
		excinfo.exception.stderr,
		r"error: argument {foo,bar}: invalid choice: 'baz' \(choose from 'foo', 'bar'\)\n$"
		)

		def test_optional_subparsers(self):
Expand Down
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Add closest choice if exists in Argparser if wrong choice picked.