def _repack(linear, n=3):
    """This ridiculous function returns chunks of n from a linear list.
    For example, _repack([1, 2, 3, 4, 5, 6], n=3) -> [[1, 2, 3], [4, 5, 6]]
    Good for unravelling ravelled data
    """
    return list(zip(*([iter(linear)] * n)))
