标签：queue
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.not_empty()：判断消息队列是否为非空。同上不可靠。
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。
Queue.task_done()：接收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()：表示等待，等到队列为空，在执行别的操作。
Queue.terminate()：表示强制关闭。
例子:
#!/usr/bin/env python
# -*- coding:utf-8 -*-
from multiprocessing import Queue
from threading import Thread
import time
"""
写一个消费者和生产者，
用多线程方式实现，
通过类的重写的方法实现。
"""
class Proceducer(Thread):
def __init__(self, queue):
super(Proceducer,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
class Consumer_even(Thread):
def __init__(self, queue):
super(Consumer_even , self).__init__()
self.queue = queue
def run(self):
try:
while not self.queue.empty():
number = self.queue.get(block=True, timeout=3)
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 e
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(block=True, timeout=3)
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 e
def main():
queue = Queue()
p = Proceducer(queue=queue)
p.start()
p.join()
time.sleep(1)
c1 = Consumer_even(queue=queue)
c2 = Consumer_odd(queue=queue)
c1.start()
c2.start()
c1.join()
c2.join()
print ("All thread terminate!")
if __name__ == '__main__':
main()结果：
put data is 1 to queue put data is 2 to queue put data is 3 to queue put data is 4 to queue put data is 5 to queue put data is 6 to queue put data is 7 to queue put data is 8 to queue put data is 9 to queue get 1 from queue EVEN, thread name is Thread-2 get 2 from queue ODD get 3 from queue EVEN, thread name is Thread-2 get 4 from queue ODD get 5 from queue EVEN, thread name is Thread-2 get 6 from queue ODD get 7 from queue EVEN, thread name is Thread-2 get 8 from queue ODD get 9 from queue EVEN, thread name is Thread-2 All thread terminate!
标签：queue
原文地址：http://blog.51cto.com/286577399/2051848
