命令行 nc.py -h 后 它 print 出 err err err err 想usage()

#   ----nc.py---------
import sys
import time

def usage():
    print "BHP Net Tool"
    print
    print "Usage:kkkkkk"
    sys.exit(0)
   

def main():
    global listen
    global port
    global execute
    global command
    global upload_destination
    global target
   
    if not len(sys.argv[1:]):
        print  "err err err err"
        
    try:
        opts,args=getopt.getopt(sys.argv[1:],"hle:t:p:cu:", \
        ["help","listen","execute","target","port","command","upload"])
    except getopt.GetoptError as err:
            print str(err)
            usage()
            
            
    for o,a in opts:
        if o in("-h","--help"):             usage()
        elif o in("-l","--listen"):         print "llllllllll"
        elif o in("-e","--execute"):        print "eeeeeeeeee"
        elif o in("-c","--commandshell"):   print "cccccccccc"
        elif o in("-u","--upload"):         print "uuuuuuuuuu"
        elif o in("-t","--target"):         print "tttttttttt"
        elif o in("-p","--port"):           print "pppppppppp"
        else:
                                            assert False,"Unhandled Option"
              
           
#sys.argv[1:]="-h"            
main()
#raw_input("\n\nPress the enter key to exit.")  
time.sleep(300)
print "******************"