在Python中的嵌套列表中查找匹配项

Question

我有两个不同大小的嵌套列表：

A = [[1, 7, 3, 5], [5, 5, 14, 10]]

B = [[1, 17, 3, 5], [1487, 34, 14, 74], [1487, 34, 3, 87], [141, 25, 14, 10]]

我想收集列表B中的所有嵌套列表，如果A [2：4] == B [2：4]并将其放入列表L：

L = [[1, 17, 3, 5], [141, 25, 14, 10]]

此外，如果匹配发生，那么我想将子列表B的最后一个元素更改为子列表A的第一个元素，因此最终解决方案将如下所示：

L1 = [[1, 17, 3, 1], [141, 25, 14, 5]]

Answer 1

看起来这样做你想要的：

> [b for b in B if b[2:4] in [a[2:4] for a in A]]
[[1, 17, 3, 5], [141, 25, 14, 10]]

但是，为了提高效率，您可能需要预先计算A的切片。

> a_slices = [a[2:4] for a in A]
> [b for b in B if b[2:4] in a_slices]
[[1, 17, 3, 5], [141, 25, 14, 10]]

这似乎符合您的新要求：

> [b[:-1] + a[:1] for b in B for a in A if b[2:4] == a[2:4]]
[[1, 17, 3, 1], [141, 25, 14, 5]]

Answer 2

[x for x in B if any(x[2:4] == y[2:4] for y in A)]