Bifurcate list based on function

Splits values into two groups, based on the result of the given filtering function.

  • Use a list comprehension to add elements to groups, based on the value returned by fn for each element.
  • If fn returns a truthy value for any element, add it to the first group, otherwise add it to the second group.
def bifurcate_by(lst, fn):
  return [
    [x for x in lst if fn(x)],
    [x for x in lst if not fn(x)]
bifurcate_by(['beep', 'boop', 'foo', 'bar'], lambda x: x[0] == 'b')
# [ ['beep', 'boop', 'bar'], ['foo'] ]