List intersection

Python, List · Nov 2, 2020

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.

def intersection(a, b):
  _a, _b = set(a), set(b)
  return list(_a & _b)

intersection([1, 2, 3], [4, 3, 2]) # [2, 3]

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