from argparse import *
import re as _re
from gettext import gettext as _, ngettext
import sys as _sys

# class ArgumentParser(_AttributeHolder, _ActionsContainer):
class ArgumentParserOpt(ArgumentParser):
    def _match_argument(self, action, arg_strings_pattern):
        # match the pattern for this action to the arg strings
        nargs_pattern = self._get_nargs_pattern(action)
        match = _re.match(nargs_pattern, arg_strings_pattern)

        # if no match, see if we can emulate optparse and return the
        # required number of arguments regardless of their values
        #
        if match is None:
            import numbers
            nargs = action.nargs if action.nargs is not None else 1
            if isinstance(nargs, numbers.Number) and len(arg_strings_pattern) >= nargs:
                return nargs

        # raise an exception if we weren't able to find a match
        if match is None:
            nargs_errors = {
                None: _('expected one argument'),
                OPTIONAL: _('expected at most one argument'),
                ONE_OR_MORE: _('expected at least one argument'),
            }
            default = ngettext('expected %s argument',
                               'expected %s arguments',
                               action.nargs) % action.nargs
            msg = nargs_errors.get(action.nargs, default)
            raise ArgumentError(action, msg)

        # return the number of arguments matched
        return len(match.group(1))

def test(argv):
    try:
        args = parser.parse_args(argv)
        print(args)
        print()
    except SystemExit:
        print()


if __name__ == '__main__':

    if True:
        ParserClass = ArgumentParserOpt
    else:
        ParserClass = ArgumentParser
    # https://bugs.python.org/issue9334 example
    parser = ParserClass(prog='a2x')
    parser.set_defaults(prog=parser.prog)
    parser.add_argument('--asciidoc-opts',
        action='store', dest='asciidoc_opts', default='',
        metavar='ASCIIDOC_OPTS', help='asciidoc options')
    parser.add_argument('--safe', action='store_true')

    test(['--asciidoc-opts', '--safe'])
    test(['--asciidoc-opts', '--safe', '--safe'])

    test(['--asciidoc-opts', '-1'])  # works in default

    test(['--asciidoc-opts', '-one'])

    test(['--asciidoc-opts=-one'])   # works in default

    test(['--safe', '--asciidoc-opts'])  # should return error, but doesnt

    parser = ParserClass(prog='nargs2')
    parser.set_defaults(prog=parser.prog)
    parser.add_argument('-a', nargs=2)
    test(['-a', '-first', '-second'])
    test(['-a', '-first'])

    parser = ParserClass(prog='karzes')
    parser.set_defaults(prog=parser.prog)
    parser.add_argument('--myopt')
    test(['--myopt', '-1,2'])