--- title: Test if every list element is falsy type: snippet language: python tags: [list] cover: jars-on-shelf-2 dateModified: 2020-11-02T19:28:27+02:00 --- Checks if the provided function returns `True` for at least one element in the list. - Use `all()` and `fn` to check if `fn` returns `False` for all the elements in the list. ```py def none(lst, fn = lambda x: x): return all(not fn(x) for x in lst) ``` ```py none([0, 1, 2, 0], lambda x: x >= 2 ) # False none([0, 0, 0]) # True ```