一个队列至少满足2个方法,put和get.

借助最小堆来实现.

这里按"值越大优先级越高"的顺序.

#coding=utf-8

from heapq import heappush, heappop

class PriorityQueue:

    def __init__(self):

        self._queue = []

    def put(self, item, priority):

        heappush(self._queue, (-priority, item))

    def get(self):

        return heappop(self._queue)[-1]

q = PriorityQueue()

q.put('world', 1)

q.put('hello', 2)

print q.get()

print q.get()