[Python数据结构] 序列中n个最大最小集

[Python数据结构] 序列中n个最大最小集

>>> import heapq
>>> nums = [1, 8, 2, 23, 7, -4, 18, 23, 42, 37, 2]
>>> heapq.nlargest(3, a)
[5, 4, 3]
>>> heapq.nsmallest(3, a)       
[1, 2, 3]
>>> 
>>> portfolio = [
... {'name': 'IBM', 'shares': 100, 'price': 91.1},
... {'name': 'AAPL', 'shares': 50, 'price': 543.22},
... {'name': 'FB', 'shares': 200, 'price': 21.09},
... {'name': 'HPQ', 'shares': 35, 'price': 31.75},
... {'name': 'YHOO', 'shares': 45, 'price': 16.35},
... {'name': 'ACME', 'shares': 75, 'price': 115.65}
... ]
>>> 
>>> heapq.nlargest(3, portfolio, key=lambda item: item['price'])
[{'name': 'AAPL', 'shares': 50, 'price': 543.22}, {'name': 'ACME', 'shares': 75, 'price': 115.65}, {'name': 'IBM', 'shares': 100, 'price': 91.1}]
>>> 
>>> heapq.heapify(nums)
>>> nums
[-4, 2, 1, 23, 7, 2, 18, 23, 42, 37, 8]
>>> heapq.heappop(nums)
-4
>>> heapq.heappop(nums)
1
>>> heapq.heappop(nums)
2
>>> heapq.heappop(nums)
2
>>> heapq.heappop(nums)
7
>>> heapq.heappop(nums)
8
>>>