argparse with optional positionals for k_smooth

arg.py

#!/usr/bin/env python

import argparse

def main():
    description = "example: ./argparse.py [--foo arg] [arg1 arg2]"
    parser = argparse.ArgumentParser(description=description)
    parser.add_argument("arg1", nargs="?", help="Argument 1")
    parser.add_argument("arg2", nargs="?", help="Argument 2")
    parser.add_argument("-f", "--foo", required=False, help="foo argument")
    args = parser.parse_args()

    if args.arg1 and args.arg2 and not args.foo:
        print "arg1: %s arg2: %s" % (args.arg1, args.arg2)

    elif args.foo and not args.arg1 and not args.arg2:
        print "foo: %s" % args.foo

    else:
        print "Fix yourself."

if __name__ == "__main__":
    main()