2.多线程简单应用

import threading,time,random
#查看线程的数量
def sing():
    for i in range(3):
        print('正在唱歌....%d'%i)
        time.sleep(random.random()*10)

def dance():
    for i in range(3):
        print('正在跳舞....%d'%i)
        time.sleep(random.random()*10)

if __name__ == "__main__":
    print("时刻关注新技术,晚会开始:%s"%time.ctime())

    t1 = threading.Thread(target=sing)
    t2 = threading.Thread(target=dance)
    t1.start()
    t2.start()

    while True:
        #输出线程数
        length = len(threading.enumerate())
        print("当前运行的线程数为:%d"%length)
        time.sleep(1)
        if length <= 1:
            break