python中的数组过滤器? [英] array filter in python?

问题描述

例如，我有两个列表

 A           = [6, 7, 8, 9, 10, 11, 12]
subset_of_A  = [6, 9, 12]; # the subset of A


the result should be [7, 8, 10, 11]; the remaining elements 

python 中是否有内置函数来执行此操作?

Is there a built-in function in python to do this?

推荐答案

如果顺序不重要，你应该使用set.difference.但是，如果您想保持顺序，只需简单的列表推导即可.

If the order is not important, you should use set.difference. However, if you want to retain order, a simple list comprehension is all it takes.

result = [a for a in A if a not in subset_of_A]

正如 delnan 所说，如果 subset_of_A 是一个实际的 set，性能将得到显着提高，因为检查 中的成员资格>set 与列表的 O(n) 相比是 O(1).

As delnan says, performance will be substantially improved if subset_of_A is an actual set, since checking for membership in a set is O(1) as compared to O(n) for a list.

A = [6, 7, 8, 9, 10, 11, 12]
subset_of_A = set([6, 9, 12]) # the subset of A

result = [a for a in A if a not in subset_of_A]

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