def bounds_elementwise(lst):
    """Given a non-empty list, returns (mins, maxes) each of which is the same
    length as the list items.

    >>> bounds_elementwise([[0,6,0], [5,0,7]])
    ([0,0,0], [5,6,7])
    """
    indices = list(range(len(lst[0])))
    mins = [min(el[i] for el in lst) for i in indices]
    maxes = [max(el[i] for el in lst) for i in indices]
    return (mins, maxes)