# example4.py
from datetime import datetime

def main(dsn, table='product', today=datetime.today()):
    "Do something on the database"
    print(dsn, table, today)

if __name__ == '__main__': # manual management before argparse
    import sys
    args = sys.argv[1:]
    if not args:
        sys.exit('usage: python %s dsn' % sys.argv[0])
    elif len(args) > 2:
        sys.exit('Unrecognized arguments: %s' % ' '.join(argv[2:]))
    main(*args)