def exist_file(x):
        if not path.isfile(x):
            raise argparse.ArgumentError("{0} does not exist".format(x))
        return x
Return user info when a valid code is passed in.
dataset/ETHPy150Open ericgibert/supersid/supersid/sidfile.py/exist_file--crossover with--dataset/ETHPy150Open clef/clef-python/tests.py/ClefIntegrationTests.test_get_login_information