Python实例:简单优先级队列实现

#coding:utf-8
'''
优先级队列
'''
import heapq

class PriorityQueue:
    def __init__(self):
        self._queue = []
        self._index = 0
    
    def push(self,item,priority):
        heapq.heappush(self._queue,( -priority,self._index,item))
        self._index += 1

    def pop(self):
        return heapq.heappop(self._queue)[-1]

class Item:
    def __init__(self,name):
        self.name = name
    
    def __repr__(self):
        return 'Item({!r})'.format(self.name)

q = PriorityQueue()
q.push(Item('foo'),1)
q.push(Item('bar'),5)
q.push(Item('spam'),4)
q.push(Item('grok'),1)

print(q.pop())