--- title: List similarity tags: list cover: sunflowers firstSeen: 2019-08-20T16:12:11+03:00 lastUpdated: 2020-11-02T19:28:35+02:00 --- Returns a list of elements that exist in both lists. - Use a list comprehension on `a` to only keep values contained in both lists. ```py def similarity(a, b): return [item for item in a if item in b] ``` ```py similarity([1, 2, 3], [1, 2, 4]) # [1, 2] ```