def key_value_pair(string):
    output = string.split('=')
    if (len(output) != 2):
        msg = ('%r is not the form of "key=value"' % string)
        raise argparse.ArgumentTypeError(msg)
    return output
def key_value_pair(string):
    output = string.split('=')
    if (len(output) != 2):
        msg = ('%r is not the form of "key=value"' % string)
        raise argparse.ArgumentTypeError(msg)
    return output