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      1. Python 可迭代队列

        时间:2023-09-29

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                  本文介绍了Python 可迭代队列的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着跟版网的小编来一起学习吧!

                  问题描述

                  我需要知道队列何时关闭并且不会有更多项目,以便我可以结束迭代.

                  I need to know when a Queue is closed and wont have more items so I can end the iteration.

                  我通过在队列中放置一个哨兵来做到这一点:

                  I did it by putting a sentinel in the queue:

                  from Queue import Queue
                  
                  class IterableQueue(Queue): 
                  
                      _sentinel = object()
                  
                      def __iter__(self):
                          return self
                  
                      def close(self):
                          self.put(self._sentinel)
                  
                      def next(self):
                          item = self.get()
                          if item is self._sentinel:
                              raise StopIteration
                          else:
                              return item
                  

                  鉴于这是队列的一种非常常见的用途,难道没有任何内置实现吗?

                  Given that this is a very common use for a queue, isn't there any builtin implementation?

                  推荐答案

                  sentinel 是生产者发送没有更多队列任务即将到来的消息的合理方式.

                  A sentinel is a reasonable way for a producer to send a message that no more queue tasks are forthcoming.

                  FWIW,您的代码可以使用 iter():

                  FWIW, your code can be simplified quite a bit with the two argument form of iter():

                  from Queue import Queue
                  
                  class IterableQueue(Queue): 
                  
                      _sentinel = object()
                  
                      def __iter__(self):
                          return iter(self.get, self._sentinel)
                  
                      def close(self):
                          self.put(self._sentinel)
                  

                  这篇关于Python 可迭代队列的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持跟版网!

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