30-seconds-of-code/python/snippets/find-index-of-all.md

title, type, tags, cover, dateModified

title	type	tags	cover	dateModified
Find all matching indexes	snippet	list	tree-roots	2020-11-02T19:27:53+02:00

Finds the indexes of all elements in the given list that satisfy the provided testing function.

• Use enumerate() and a list comprehension to return the indexes of the all element in lst for which fn returns True.

def find_index_of_all(lst, fn):
  return [i for i, x in enumerate(lst) if fn(x)]

find_index_of_all([1, 2, 3, 4], lambda n: n % 2 == 1) # [0, 2]