diff --git a/Lib/argparse.py b/Lib/argparse.py index 0658472acf0..f0cfe27eb85 100644 --- a/Lib/argparse.py +++ b/Lib/argparse.py @@ -1969,17 +1969,12 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer): # if we didn't consume all the argument strings, there were extras extras.extend(arg_strings[stop_index:]) - # if we didn't use all the Positional objects, there were too few - # arg strings supplied. - if positionals: - self.error(_('too few arguments')) - # make sure all required actions were present - for action in self._actions: - if action.required: - if action not in seen_actions: - name = _get_action_name(action) - self.error(_('argument %s is required') % name) + required_actions = [_get_action_name(action) for action in self._actions + if action.required and action not in seen_actions] + if required_actions: + self.error(_('the following arguments are required: %s') % + ', '.join(required_actions)) # make sure all required groups had one option present for group in self._mutually_exclusive_groups: diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py index 2836e7ec943..b0e9a03ea81 100644 --- a/Lib/test/test_argparse.py +++ b/Lib/test/test_argparse.py @@ -4480,6 +4480,67 @@ class TestArgumentTypeError(TestCase): else: self.fail() +# ========================= +# MessageContentError tests +# ========================= + +class TestMessageContentError(TestCase): + + def test_missing_argument_name_in_message(self): + parser = ErrorRaisingArgumentParser(prog='PROG', usage='') + parser.add_argument('req_pos', type=str) + parser.add_argument('-req_opt', type=int, required=True) + parser.add_argument('need_one', type=str, nargs='+') + + with self.assertRaises(ArgumentParserError) as cm: + parser.parse_args([]) + msg = str(cm.exception) + self.assertRegex(msg, 'req_pos') + self.assertRegex(msg, 'req_opt') + self.assertRegex(msg, 'need_one') + with self.assertRaises(ArgumentParserError) as cm: + parser.parse_args(['myXargument']) + msg = str(cm.exception) + self.assertNotIn(msg, 'req_pos') + self.assertRegex(msg, 'req_opt') + self.assertRegex(msg, 'need_one') + with self.assertRaises(ArgumentParserError) as cm: + parser.parse_args(['myXargument', '-req_opt=1']) + msg = str(cm.exception) + self.assertNotIn(msg, 'req_pos') + self.assertNotIn(msg, 'req_opt') + self.assertRegex(msg, 'need_one') + + def test_optional_optional_not_in_message(self): + parser = ErrorRaisingArgumentParser(prog='PROG', usage='') + parser.add_argument('req_pos', type=str) + parser.add_argument('--req_opt', type=int, required=True) + parser.add_argument('--opt_opt', type=bool, nargs='?', + default=True) + with self.assertRaises(ArgumentParserError) as cm: + parser.parse_args([]) + msg = str(cm.exception) + self.assertRegex(msg, 'req_pos') + self.assertRegex(msg, 'req_opt') + self.assertNotIn(msg, 'opt_opt') + with self.assertRaises(ArgumentParserError) as cm: + parser.parse_args(['--req_opt=1']) + msg = str(cm.exception) + self.assertRegex(msg, 'req_pos') + self.assertNotIn(msg, 'req_opt') + self.assertNotIn(msg, 'opt_opt') + + def test_optional_positional_not_in_message(self): + parser = ErrorRaisingArgumentParser(prog='PROG', usage='') + parser.add_argument('req_pos') + parser.add_argument('optional_positional', nargs='?', default='eggs') + with self.assertRaises(ArgumentParserError) as cm: + parser.parse_args([]) + msg = str(cm.exception) + self.assertRegex(msg, 'req_pos') + self.assertNotIn(msg, 'optional_positional') + + # ====================== # parse_known_args tests # ====================== diff --git a/Misc/NEWS b/Misc/NEWS index 83aa53aa0af..95626462675 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -187,6 +187,9 @@ Core and Builtins Library ------- +- Issue #10424: Argparse now includes the names of the missing required + arguments in the missing arguments error message. + - Issue #12168: SysLogHandler now allows NUL termination to be controlled using a new 'append_nul' attribute on the handler.