线程 事件

import time
import random
from threading import Thread,Event

def connect_db(e):
    count = 0
    while count<3:
        e.wait(1)     #状态为false的时候，我只等待1s就结束
        if e.is_set() == True:
            print('连接数据库成功')
            break
        else:
            count+=1
            print('第%s次连接失败'%count)
    else:
        raise TimeoutError('连接数据库超时')



def check_web(e):
    time.sleep(random.randint(0, 3))
    e.set()

e=Event()
t1 = Thread(target = connect_db,args=(e,))
t2 = Thread(target = check_web,args=(e,))
t1.start()
t2.start()