22 lines
478 B
Markdown
22 lines
478 B
Markdown
---
|
|
title: intersection
|
|
tags: list,beginner
|
|
firstSeen: 2019-08-20T15:14:26+03:00
|
|
lastUpdated: 2020-11-02T19:28:05+02:00
|
|
---
|
|
|
|
Returns a list of elements that exist in both lists.
|
|
|
|
- Create a `set` from `a` and `b`.
|
|
- Use the built-in set operator `&` to only keep values contained in both sets, then transform the `set` back into a `list`.
|
|
|
|
```py
|
|
def intersection(a, b):
|
|
_a, _b = set(a), set(b)
|
|
return list(_a & _b)
|
|
```
|
|
|
|
```py
|
|
intersection([1, 2, 3], [4, 3, 2]) # [2, 3]
|
|
```
|