def __init__(self,
                 option_strings,
                 dest,
                 nargs=None,
                 const=None,
                 default=None,
                 type=None,
                 choices=None,
                 required=False,
                 help=None,
                 metavar=None):
        if nargs == 0:
            raise ValueError('nargs for append actions must be > 0; if arg '
                             'strings are not supplying the value to append, '
                             'the append const action may be more appropriate')
        if const is not None and nargs != OPTIONAL:
            raise ValueError('nargs must be %r to supply const' % OPTIONAL)
        super(_AppendAction, self).__init__(
            option_strings=option_strings,
            dest=dest,
            nargs=nargs,
            const=const,
            default=default,
            type=type,
            choices=choices,
            required=required,
            help=help,
            metavar=metavar)
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/argparse/argparse.py/_AppendAction.__init__/original