30-seconds-of-code/snippets/find_index.md

title, tags

title	tags
find_index	list,intermediate

Returns the index of the first element in the provided list that satisfies the provided testing function.

• Use list comprehension, enumerate() and next() to return the index of the first element in lst for which fn returns True.

def find_index(lst, fn):
  return next(i for i, x in enumerate(lst) if fn(x))

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