30秒学会 Python 片段 – List intersection based on function

Returns a list of elements that exist in both lists, after applying the provided function to each list element of both.

• Create a set, using map() to apply fn to each element in b.
• Use a list comprehension in combination with fn on a to only keep values contained in both lists.

代码实现

def intersection_by(a, b, fn):
  _b = set(map(fn, b))
  return [item for item in a if fn(item) in _b]

使用样例

from math import floor

intersection_by([2.1, 1.2], [2.3, 3.4], floor) # [2.1]

翻译自：https://www.30secondsofcode.org/python/s/intersection-by