def create_bin_permutations(length):
    """Return sorted list of permutations of 0, 1 of length. I.e, 2 -->
    ['00', '01', '10', '11']
    """
    output = []
    for num in range(0, length**2):
        perm = f'{num:b}'
        perm = perm.zfill(length)
    return output