队列

其实好多包都实现了队列这种数据结构，本篇重点介绍multiprocessing(mp)库的队列数据结构。

#
# Queue type using a pipe, buffer and thread
#

class Queue(object):

    def put(self, obj, block=True, timeout=None):
        # ...

    def get(self, block=True, timeout=None):
        # ...

    def qsize(self):
        # Raises NotImplementedError on Mac OSX because of broken sem_getvalue()
        return self._maxsize - self._sem._semlock._get_value()

    def empty(self):
        return not self._poll()

    def full(self):
        return self._sem._semlock._is_zero()
        
        
#
# Simplified Queue type -- really just a locked pipe
#

class SimpleQueue(object):
    
    def empty(self):
        return not self._poll()
    
    def get(self):
        # ...

    def put(self, obj):
        # ...

可见SimpleQueue基本只实现了队列的get/put方法，而Queue还可查询队列的很多状态