Python编程：heapq模块堆排序

import heapq

# 添加元素，容器是list列表，元素存放顺序是小根堆的顺序
h = []
heapq.heappush(h, 2)
heapq.heappush(h, 3)

h
Out[6]: 
[2, 3]


# 列表转换为堆
lst = [2, 3, 4, 6, 9, 1, 5]
heapq.heapify(lst)
lst
Out[9]: 
[1, 3, 2, 6, 9, 4, 5]


# 弹出最小值
heapq.heappop(lst)
Out[10]: 
1

lst
Out[11]: 
[2, 3, 4, 6, 9, 5]


# 弹出最小值，添加新元素
heapq.heapreplace(lst, 8)
Out[14]: 
2
lst
Out[15]: 
[3, 6, 4, 8, 9, 5]


# 和根元素比较，如果比其大则替换
heapq.heappushpop(lst, 4)
Out[16]: 
3
lst
Out[17]: 
[4, 6, 4, 8, 9, 5]

# 和根元素比较，如果比其小则不替换
heapq.heappushpop(lst, 3)
Out[18]: 
3
lst
Out[19]: 
[4, 6, 4, 8, 9, 5]


# 合并堆
h = [10, 11, 13]
l = heapq.merge(lst, h)
list(l)
Out[25]: 
[4, 6, 4, 8, 9, 5, 10, 11, 13]

# 查询最大的n个元素
heapq.nlargest(3, lst)
Out[26]: 
[9, 8, 6]

# 查询最小的n个元素
heapq.nsmallest(3, lst)
Out[27]: 
[4, 4, 5]