from threading import Thread,Semaphore      #类似锁的一个东西
import time
lock_num=Semaphore(2)            #设置锁的数量
def test(name):
    lock_num.acquire()
    print(f'{name}已加入')
    time.sleep(2)
    print(f'{name}已离开')
    lock_num.release()
if __name__ == '__main__':
    l=['马云','马化腾','马斯克','马保国',]
    for name in l:
        t=Thread(target=test,args=(name,))
        t.start()