event.wait() 等待一定时间，或者当遇到event.set() 时，继续执行 

event.clear() 清除信号 

event.set() 设置信号 

event.isset() 判断信号 

 

例一： 红绿灯

#event 实现两个线程之间的交互 import time, threading def lighter():     if not event.is_set():       event.set()     count = 0     while True:       if count<10:          print('the green light is run %s'%count)       elif count<15:          print('the yellow light is run %s'%count)       elif count<20:           print('the red light is run %s'%count)           event.clear()       else:           count = 0           event.set()       time.sleep(1)       count += 1 def cars(n):     while True:       if event.is_set():           print('%s is running'%n)       else:           print('%s is stoping'%n)       time.sleep(1) event = threading.Event() light = threading.Thread(target=lighter, args=()) light.start() car = threading.Thread(target=cars, args=('tesl', )) car.start() 例二 开关门

import threading, time, random def door():     door_count_number = 0     while True:         if door_state.is_set():             print('the door is open')             door_count_number += 1         else:             print('the door has been closed')             door_count_number = 0             door_state.wait()         if door_count_number > 3:             door_state.clear()         time.sleep(0.5) def staff(n):     print('%s is comming'%n)     while True:       if door_state.is_set():         print('%s is pass'%n)         break       else :         door_state.set()         print('staff[%s]sees door got closed, swipped the card')       time.sleep(0.5) door_state = threading.Event() Door = threading.Thread(target=door) Door.start() for i in range(5):     p = threading.Thread(target=staff, args=(i, ))     time.sleep(random.randrange(3))     p.start()