- python线程的事件用于主线程控制其他线程的执行，事件是一个简单的线程同步对象，其主要提供以下几个方法：
- clear 将flag设置为“False”
- set 将flag设置为“True”
- is_set 判断是否设置了flag
- wait 会一直监听flag，如果没有检测到flag就一直处于阻塞状态
- 事件处理的机制：全局定义了一个“Flag”，当flag值为“False”，那么event.wait()就会阻塞，当flag值为“True”，那么event.wait()便不再阻塞。
#!/usr/bin/env python
# coding:utf-8
import threading
import time
event = threading.Event()
def lighter():
count = 0
event.set() # green
while True:
if 5 < count <= 10:
event.clear() # red
print("\33[41;1mred light is on...\033[0m")
elif count > 10:
event.set() # green
count = 0
else:
print("\33[42;1mgreen light is on...\033[0m")
time.sleep(1)
count += 1
def car(name):
while True:
if event.is_set():
print("[%s] running..." % name)
time.sleep(1)
else:
print("[%s] sees red light,waiting..." % name)
event.wait()
print("[%s] green light is on,start going..." % name)
if __name__ == '__main__':
light = threading.Thread(target=lighter)
light.start()
car = threading.Thread(target=car, args=('OOOO',))
car.start()
