command-line options and arguments using getopt

I'm trying to write a piece of code in python to get command-line options and arguments using getopt module. Here is my code:

import getopt
impor开发者_如何学编程t sys

def usage ():
    print('Usage')

def main():
    try:
        opts, args = getopt.getopt(sys.argv[1:], 'xy:')
    except getopt.GetoptError as err:
        print(err)
        usage()
        sys.exit()

    for o,a in opts:
        if o in ("-x", "--xxx"):
            print(a)
        elif o in ("-y", "--yyy"):
            print(a)
        else:
            usage()
            sys.exit()

if __name__ == "__main__":
    main()

The problem is that I can't read the argument of option x, but I can read the argument of y. What should I do to fix this?

Try getopt.getopt(sys.argv[1:], 'x:y:')

http://docs.python.org/library/getopt.html

Parses command line options and parameter list. args is the argument list to be parsed, without the leading reference to the running program. Typically, this means sys.argv[1:]. options is the string of option letters that the script wants to recognize, with options that require an argument followed by a colon (':'; i.e., the same format that Unix getopt() uses).

If you want to read argument then the option should've ':' next to it, there are few options which doesn't need argument like 'help' and 'verbose' which don't need ':' to be followed.

import getopt
import sys

def usage ():
    print('Usage')

def main():
    try:
        opts, args = getopt.getopt(sys.argv[1:], 'x:y:h', ['xxx=', 'yyy=', 'help='])
    except getopt.GetoptError as err:
        print(err)
        usage()
        sys.exit()

    for opt,arg in opts:
        if opt in('-h', '--help'):
            usage()
            sys.exit( 2 )
        elif opt in ('-x', '--xxx'):
            print(arg)
        elif opt in ('-y', '--yyy'):
            print(arg)
        else:
            usage()
            sys.exit()

if __name__ == "__main__":
    main()