import argparse

def args_validation(valid_list, valid_value):
    assert valid_value in valid_list, ‘invalid {}, valid args:{}’.format(valid_value, ‘/’.join(valid_list))

arg_parser = argparse.ArgumentParser()
arg_parser.add_argument(‘--trainer-pkg-type’)

args = arg_parser.parse_args()

allowed_pkg_type = [
    ‘src’,
    ‘whl’,
    ‘bin’,
]

args_validation(allowed_pkg_type, args.trainer_pkg_type)