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How can we get the n largest items from a list, you may write code like this:
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def nlargest_sort(a_list, n): if n > len(a_list): print("not enough nums") else: a_list.sort() return a_list[-n:][::-1] a = [1, 45, 98, 980, 302, 23, 45, 66, 76, 34, 23, 45, 65, 4, 545, 65] print(nlargest_sort(a, 3)) # Outputs: [980, 545, 302] |
It's will work, but we can use 'heapq' to write much shorter and more efficient code：
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def nlargest_heapq(a_list, n): if n > len(a_list): print("not enough nums") else: return heapq.nlargest(n, a_list) a = [1, 45, 98, 980, 302, 23, 45, 66, 76, 34, 23, 45, 65, 4, 545, 65] print(nlargest_heapq(a, 3)) # Outputs: [980, 545, 302] |
Similarly to "n largest", you can use 'heap.nsmallest(n, some_list)' to get the n smallest nums from a list.
