Python heapq使用详解及实例代码

importheapq

importrandom

classTopkHeap(object):

  def__init__(self, k):

    self.k=k

    self.data=[]

  defPush(self, elem):

    iflen(self.data)

      heapq.heappush(self.data, elem)

    else:

      topk_small=self.data[0]

      ifelem > topk_small:

        heapq.heapreplace(self.data, elem)

  defTopK(self):

    return[xforxinreversed([heapq.heappop(self.data)forxinxrange(len(self.data))])]

if__name__=="__main__":

  print"Hello"

  list_rand=random.sample(xrange(1000000),100)

  th=TopkHeap(3)

  foriinlist_rand:

    th.Push(i)

  printth.TopK()

  printsorted(list_rand, reverse=True)[0:3]

classBtmkHeap(object):

  def__init__(self, k):

    self.k=k

    self.data=[]

  defPush(self, elem):

    # Reverse elem to convert to max-heap

    elem=-elem

    # Using heap algorighem

    iflen(self.data)

      heapq.heappush(self.data, elem)

    else:

      topk_small=self.data[0]

      ifelem > topk_small:

        heapq.heapreplace(self.data, elem)

  defBtmK(self):

    returnsorted([-xforxinself.data])