def drop_right_t(n):
    """
    Transformation for Sequence.drop_right
    :param n: number to drop from right
    :return: transformation
    """
    if n <= 0:
        end_index = None
    else:
        end_index = -n
    return Transformation(
        'drop_right({0})'.format(n),
        lambda sequence: sequence[:end_index],
        None
    )