34 lines
1.0 KiB
Python
34 lines
1.0 KiB
Python
import heapq
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# heapq里有两个函数，nlargest和nsmallest可以找最大N个和最小N个；
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# 参数接受一个列表和一个N
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def max_n(search_list, n):
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list_max_n = heapq.nlargest(n ,search_list)
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return list_max_n
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def min_n(search_list, n):
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list_min_n = heapq.nsmallest(n, search_list)
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return list_min_n
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# 这两个函数都提供了一个key输入来实现在字典列表中的应用
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def max_in_dictlist(search_list, n, key):
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max_key_n = heapq.nlargest(n, search_list, key=lambda dic : dic[key])
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return max_key_n
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# 如果寻找最大N个和最小N个元素，这个方法在N的规模不大的时候好用；
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# 当日在N=1的时候还是用max和min方法更快，要是N巨大那就得排序了
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# heapq事实上是一个堆方法，将列表在底层序列化为一个最小堆
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def heapq_func():
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ori_list = [1,2,3,4,5]
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heap = list(ori_list)
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# 将列表进行堆排序
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heapq.heapify(heap)
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# 弹出堆顶元素
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heapq.heappop(heap)
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if __name__ == '__main__':
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l = [1,2,3,4,5]
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print(max_n(l, 3))
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