Python多进程编程中遇到的奇怪问题咨询

#coding:utf-8
import os, sys, time
from multiprocessing import Pool, Queue, Manager

class Out(object):
----def out(self,queue):
--------print(“start”)
--------while True:
------------item = queue.get()
------------print(item)
------------time.sleep(0.01)


class Data(object):

----def init(self):
--------self.pool = Pool(2)
--------self.queue = Manager().Queue()
--------self.out = Out()

----def put(self,item):
--------self.queue.put(item)


----def start(self):
--------print(self.queue.qsize())
--------for _ in range(2):
------------self.pool.apply_async(self.out.out,(self.queue,))

if name == ‘main’:

----data = Data()
----for i in range(1000):
--------data.put(i)
----data.start()
----data.pool.close()
----data.pool.join()
----time.sleep(5)