Python提供了Queue模块来专门实现消息队列Queue对象
Queue对象实现一个fifo队列(其他的还有lifo、priority队列,这里不再介绍)。queue只有maxsize一个构造参数,用来指定队列容量,指定为0的时候代表容量无限。主要有以下成员函数: Queue.qsize():返回消息队列的当前空间。返回的值不一定可靠。 Queue.empty():判断消息队列是否为空,返回True或False。同样不可靠。 Queue.full():类似上边,判断消息队列是否满 Queue.put(item, block=True, timeout=None):往消息队列中存放消息。block可以控制是否阻塞,timeout指定阻塞时候的等待时间。如果不阻塞或者超时,会引起一个full exception。 Queue.put_nowait(item):相当于put(item, False). Queue.get(block=True, timeout=None):获取一个消息,其他同put。以下两个函数用来判断消息对应的任务是否完成。 Queue.task_done():接受消息的线程通过调用这个函数来说明消息对应的任务已完成。 Queue.join(): 实际上意味着等到队列为空,再执行别的操作
例子:
#!/usr/bin/env python# -*- coding:utf-8 -*-# @time: 2017/12/18 19:31# Author: caicai# @File: demon3.py'''写一个消费者和生产者,为了练习多线程,用多线程的方式实现,并通过类的重写的方法来实现'''from Queue import Queuefrom threading import Threadimport time#生成类,输出一堆数字class Proceduer(Thread): def __init__(self,queue): super(Proceduer, self).__init__() self.queue = queue def run(self): try: for i in xrange(1,10): print("put data is: {0} to queue".format(i)) self.queue.put(i) except Exception as e: print("put data error!") raise e#消费者类class Consumer_odd(Thread): def __init__(self,queue): super(Consumer_odd, self).__init__() self.queue = queue def run(self): try: while not self.queue.empty(): number = self.queue.get() if number % 2 != 0: print("get {0} from queue ODD".format(number)) else: self.queue.put(number) time.sleep(1) except Exception as e: raise eclass Consumer_even(Thread): def __init__(self,queue): super(Consumer_even, self).__init__() self.queue = queue def run(self): try: while not self.queue.empty(): #queue.empty() number = self.queue.get() if number % 2 == 0: print("get {0} from queue EVEN,thread name is: {1}".format(number, self.getName())) else: self.queue.put(number) time.sleep(1) except Exception as e: raise edef main(): queue = Queue() p = Proceduer(queue=queue) p.start() p.join() time.sleep(1) c1 = Consumer_odd(queue=queue) c2 = Consumer_even(queue=queue) c1.start() c2.start() c1.join() c2.join() print("All threads terminate!")if __name__ == '__main__': main()输出结果:put data is: 1 to queueput data is: 2 to queueput data is: 3 to queueput data is: 4 to queueput data is: 5 to queueput data is: 6 to queueput data is: 7 to queueput data is: 8 to queueput data is: 9 to queueget 1 from queue ODDget 2 from queue EVEN,thread name is: Thread-3get 5 from queue ODDget 6 from queue EVEN,thread name is: Thread-3get 7 from queue ODDget 8 from queue EVEN,thread name is: Thread-3get 9 from queue ODDget 4 from queue EVEN,thread name is: Thread-3get 3 from queue ODDAll threads terminate!