1. python線程的事件用于主線程控制其他線程的執(zhí)行，事件是一個簡單的線程同步對象，其主要提供以下幾個方法：

• clear 將flag設(shè)置為“False”
• set 將flag設(shè)置為“True”
• is_set 判斷是否設(shè)置了flag
• wait 會一直監(jiān)聽flag，如果沒有檢測到flag就一直處于阻塞狀態(tài)

2. 事件處理的機制：全局定義了一個“Flag”，當(dāng)flag值為“False”，那么event.wait()就會阻塞，當(dāng)flag值為“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()