多线程，多进程（2）

1.多线程等待

import threading,time

def run():

         # time.sleep(3)

         print('哈哈哈')

start_time = time.time()

threads = []  #存放启动的5个线程

for i in range(5):

         t = threading.Thread(target=run)

         t.start()#

         threads.append(t)

for lyl in threads:  #主线程循环等待5个子线程执行结束

         lyl.join()

end_time = time.time()

print('run_time..',end_time-start_time)

2.