#This problem has you write a nested loop to process a list of list of int, and accumulate a list of list of int. The starter code #provides an accumulator for the result and a loop over the lists, and you need to write the code that checks whether sublist #contains only even ints.
#
#You'll probably want a one-way flag: a Boolean variable that starts out as True and is set to False if you find an odd int in the #sublist. You'll need to check the value of this variable to figure out whether to append sublist to the even_lists accumulator.
def only_evens(lst):
    """ (list of list of int) -> list of list of int

    Return a list of the lists in lst that contain only even integers.

    >>> only_evens([[1, 2, 4], [4, 0, 6], [22, 4, 3], [2]])
    [[4, 0, 6], [2]]
    """

    even_lists = []
    check = 0
    for sublist in lst:
        for item in sublist:
            if item % 1 == check:
                even_lists.append(sublist)
    return even_lists