详解Python3定时器任务代码

import timeimport sysimport signalimport datetimeimport threading#定时器def schedule_update():  t = threading.Timer(0, event_func)  t.setDaemon(True)  t.start()#执行函数def event_func():  now_time = datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')  print(now_time)  exec_update()  #update_openvas_dbs_from_cache()  interval_time = delay_time()  t = threading.Timer(interval_time, event_func)  t.setDaemon(True)  t.start()#取时间点def delay_time():  # now time  now_time = datetime.datetime.now()  # tomorrow time  next_time = now_time + datetime.timedelta(days=+1)  next_year = next_time.date().year  next_month = next_time.date().month  next_day = next_time.date().day  # get tomorrow 00:00  next_time = datetime.datetime.strptime(str(next_year)+"-"+str(next_month)+"-"+str(next_day)+" 00:00:00", "%Y-%m-%d %H:%M:%S")  # get secondes  delay_time = (next_time - now_time).total_seconds()  return delay_timedef quit_sys(signum, frame):  sys.exit()#接收Cif __name__ == "__main__":  try:    signal.signal(signal.SIGINT, quit_sys)    signal.signal(signal.SIGTERM, quit_sys)    schedule_update()    print("schedule_update server starting up.../nHit Ctrl-C to quit./n")    while 1:      time.sleep(1)  except Exception as e:    print(e)