多处理队列子类问题

时间:2015-12-15 14:53:27

标签: python-3.x multiprocessing

我想将multiprocessing.Queue子类化,以实现抓取队列块的进程。唯一的问题是,我得到一个奇怪的TypeError?

#!/usr/bin/env python

#whaaaaa!?

from multiprocessing import Queue

class BufferQueue(Queue):
    '''A thread/process safe queue for append/popleft operations with the import
    buffer.'''

    def __init__(self, **kwargs):
        super(BufferQueue,self).__init__(**kwargs)

    def consume(self, lim):
        '''Consume up to but no more than lim elements and return them in a new
        list, cleaning up the buffer.

        @params
        lim -- the maximum (limit) to consume from the list.  If less items
        exist in the list then that's fine too.
        '''
        lim = len(queue) if len(queue) < lim else lim
        return [self.popleft() for i in range(lim)]

对此进行测试(我把它拆分出来,以便我不会拉其他任何东西)

| => ./tests/wtf_queue.py 
Traceback (most recent call last):
  File "./tests/wtf_queue.py", line 10, in <module>
    class BufferQueue(Queue):
TypeError: method expected 2 arguments, got 3

编辑/更新:

1 个答案:

答案 0 :(得分:10)

multiprocessing.Queue是一种创建队列的方法,因此您应该将其用作函数my_queue = Queue()

>>> from multiprocessing import Queue
>>> type(Queue)
<class 'method'>

正如您所看到的,不是&#39;类型&#39;,您将用它来进行子类化。

如果您想实现自己的队列,可以查看queue.Queue

修改

如果要从多处理子类化队列,请改用multiprocessing.queues.Queue,这是multiprocessing.Queue()

返回的对象的类型