python使用Queue实现优先级队列详解编程语言

使用Queue.Queue实现的线程安全的优先级队列：

import Queue 
 
class PriorityQueue(Queue.Queue): 
    def _put(self, item): 
        data, priority = item 
        self._insort_right((priority, data)) 
 
    def _get(self): 
        return self.queue.pop(0)[1] 
 
    def _insort_right(self, x): 
        """Insert item x in list, and keep it sorted assuming a is sorted. 
 
        If x is already in list, insert it to the right of the rightmost x.        
        """ 
        a = self.queue 
        lo = 0         
        hi = len(a) 
 
        while lo < hi: 
            mid = (lo+hi)/2 
            if x[0] < a[mid][0]: hi = mid 
            else: lo = mid+1 
        a.insert(lo, x) 
 
def test(): 
    pq = PriorityQueue() 
 
    pq.put(('b', 1)) 
    pq.put(('a', 1)) 
    pq.put(('c', 1)) 
    pq.put(('z', 0)) 
    pq.put(('d', 2)) 
 
    while not pq.empty(): 
        print pq.get(),    
 
test() # prints z b a c d