Python itertools

itertools.py

from itertools import zip_longest


def splitby(xs, f):
    """Split a list by a function.

    >>> splitby([{'a': 1}, {'b': 2}, {'a': 3}], lambda x: x.get('a'))
    [[{'a': 1}, {'b': 2}], [{'a': 3}]]
    
    >>> splitby([1, 0, 0, 1, 0], lambda x: x == 1)
    [[1, 0, 0], [1, 0]]
    """
    index = [i for i, v in enumerate(map(lambda x: True if f(x) else False, xs)) if v]
    return [xs[start:stop] for start, stop in zip_longest(index, index[1:])]