Python Multiprocessing Queue

One of my old post from CSDN.

import multiprocessing, Queue
from multiprocessing import Process
from time import sleep
from datetime import datetime

class MultiProcessProducer(multiprocessing.Process):
    """"""

    #----------------------------------------------------------------------
    def __init__(self,num, queue):
        """Constructor"""
        multiprocessing.Process.__init__(self)
        self.num = num
        self.queue = queue

    def run(self):
        t1 = datetime.now()
        print 'producer start', self.num, t1
        for i in range(1000000):
            self.queue.put((i, self.num))
            #print 'producer put', i, self.num
        t2 = datetime.now()
        print 'producer exit', self.num, t2
        print 'producer', self.num, t2-t1


class MultiProcessConsumer(multiprocessing.Process):
    """"""

    #----------------------------------------------------------------------
    def __init__(self,num, queue):
        """Constructor"""
        multiprocessing.Process.__init__(self)
        self.num = num
        self.queue = queue

    def run(self):
        t1 = datetime.now()
        print 'consumer start', self.num, t1
        while True:
            d = self.queue.get()
            if d != None:
                #print 'consumer get', d, self.num
                continue
            else:
                break
        t2 = datetime.now()
        print 'consumer exit', self.num, t2
        print 'consumer', self.num, t2-t1

def main():
    #create queue
    queue = multiprocessing.Queue()

    #create processes
    producer = []
    for i in range(1):
        producer.append(MultiProcessProducer(i, queue))

    consumer = []
    for i in range(2):
        consumer.append(MultiProcessConsumer(i, queue))

    #start processes
    for i in range(len(producer)):
        producer[i].start()

    for i in range(len(consumer)):
        consumer[i].start()

    #wait for processs to exit
    for i in range(len(producer)):
        producer[i].join()

    for i in range(len(consumer)):
        queue.put(None)

    for i in range(len(consumer)):
        consumer[i].join()

    print 'finish'


if __name__ == "__main__":
    main()