import heapqclass 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‘),2)q.push(Item(‘grok‘),1)print(q.pop())print(q.pop())print(q.pop())print(q.pop())   Item(‘bar‘)   Item(‘spam‘)   Item(‘foo‘)   Item(‘grok‘)