import timeimport randomfrom multiprocessing import Process,Queuedef producer(q,name,food):    for i in range(4):        time.sleep(random.random())        f = "{}生产出一个{}".format(name,food)        print(f)        q.put(f)def consumer(q,name):    while True:        food = q.get()        if food is None:            print("{}获取空，退出".format(name))            break        time.sleep(random.random())        print("{}消费了一个{}".format(name,food))if __name__ == '__main__':    q = Queue(10)    p1 = Process(target=producer,args=(q,"生产者1号","包子"))    p2 = Process(target=producer,args=(q,"生产者2号","馒头"))    c1 = Process(target=consumer,args=(q,"消费者1号"))    c2 = Process(target=consumer,args=(q,"消费者2号"))    c3 = Process(target=consumer,args=(q,"消费者3号"))    p1.start()    p2.start()    c1.start()    c2.start()    c3.start()    p1.join()    p2.join()    q.put(None)    q.put(None)    q.put(None)

import timeimport randomfrom multiprocessing import Process,JoinableQueuedef producer(q,name,food):    for i in range(4):        time.sleep(random.random())        f = "{}生产出一个{}".format(name,food)        print(f)        q.put(f)    q.join()   #生产周期变长，要等到所生产的数据被处理完，这个子进程才结束def consumer(q,name):    while True:        food = q.get()        time.sleep(random.random())        print("{}消费了一个{}".format(name,food))        q.task_done()if __name__ == '__main__':    q = JoinableQueue(10)    p1 = Process(target=producer,args=(q,"生产者1号","包子"))    p2 = Process(target=producer,args=(q,"生产者2号","馒头"))    c1 = Process(target=consumer,args=(q,"消费者1号"))    c2 = Process(target=consumer,args=(q,"消费者2号"))    c3 = Process(target=consumer,args=(q,"消费者3号"))    p1.start()    p2.start()    c1.daemon = True  #设置为守护进程，主进程中的代码执行完毕之后，该守护进程自动结束    c2.daemon = True    c3.daemon = True    c1.start()    c2.start()    c3.start()    p1.join()   #感知一个进程的结束    p2.join()