守护线程

import threading,time

def run():
    time.sleep(3)
    print('哈哈哈')


for i in range(50):
    t = threading.Thread(target=run)
    t.setDaemon(True) #把子线程设置成守护线程 (主线程一死,守护线程就死)
    t.start()

print('Done,运行完成.')
time.sleep(3)