#!/usr/bin/env python
import bisect
from Queue import Queue, Empty #thread-safe Queue

class PriorityQueue(Queue):
	def _init(self, maxsize):
		self.maxsize = maxsize;
		self.queue = [];
	def _get(self):
		return self.queue.pop(0);
	def _put(self, item):
		if item is None:
			raise Exception('PriorityQueue does not take None')
		bisect.insort(self.queue, item)