Python Threading 模块计算所有线程的执行时间

import threading
import time

def run(n):
    print("task",n)
    time.sleep(1)

t_objs = []
start_time = time.time()
for i in range(1,6):
    t = threading.Thread(target=run,args=("t-%s" %i,))
    t.start()
    t_objs.append(t)

for t in t_objs:
    t.join()

print("-----all threads has finished-----")
print("cost:",time.time() - start_time)