argv, cannot push, keep here

# obtain target IP and options
visualize = ''
target_ip = ''
def usage():
    print '-h for help'
    print '-t for target IP'

try:
    opts, args = getopt.getopt(sys.argv[1:], "ht:vd", ["help", "targetip=", "visualize", "debug"])
except getopt.GetoptError:
    usage()
        print 'err'
    sys.exit(2)
for opt, arg in opts:
    if opt in ("-h", "--help"):
        usage()
                print 'help help'
        sys.exit()
    elif opt in ("-t", "--targetip"):
        target_ip = arg
    elif opt in ('-v', '--visualize'):
        visualize = True
    elif opt in ('-d', '--debug'):
        global _debug
        _debug = 1
if visualize:
    print 'visualize'
else:
    print 'no v'
if target_ip == '':
    print 'Shall we indicate target AP or Ctrllr IP'
    sys.exit()
else:
    print target_ip