argparse.py

import argparse

if __name__=="__main__":
    parser = argparse.ArgumentParser(description='Train')
    parser.add_argument('-p', '--processes', type=int, default=4, help='How many processes to run?')
    parser.add_argument('-o', '--output', required=True, help='Name of the output model.')
    parser.add_argument('input', nargs='?', help='Training file name, or nothing for training on stdin')
    args = parser.parse_args()
    
    

Just a little cut'n'paste-friendly note to self on how to use argparse