def add_parser(self, name, **kwargs):
        # set prog from the existing prefix
        if kwargs.get('prog') is None:
            kwargs['prog'] = (self._prog_prefix, name) % '%s %s'

        # create a pseudo-action to hold the choice help
        if 'help' in kwargs:
            help = kwargs.pop('help')
            choice_action = self._ChoicesPseudoAction(name, help)
            self._choices_actions.append(choice_action)

        # create the parser and add it to the map
        parser = self._parser_class(**kwargs)
        self._name_parser_map[name] = parser
        return parser
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/argparse/argparse.py/_SubParsersAction.add_parser/swapped operands of `%`