线程锁

import threading,time
num=1
lock=threading.Lock()  #申请一把锁

def run():
    time.sleep(1)
    global num
    lock.acquire()  #加锁 #python3里面不加也无所谓,python2里面要加锁
    num+=1
    lock.release()  #解锁

ts=[]
for i in range(50):
    t = threading.Thread(target=run)
    t.start()
    ts.append(t)
[t.join() for t in ts]
print(num)

# 守护线程
# 只要主线程结束,那么子线程立即结束,不管子线程有没有运行完成