Как тестировать cmd скрипты на python?

import sys
import os
from cmd import Cmd
USING_READLINE = True

class Cli(Cmd,object):
    def do_foofail(self):
        if USING_READLINE is True:
            print ""
        else:
            print "try again"
if __name__ == '__main__':
    cmdLine = Cli()
    cmdLine.cmdloop()