def truly_relativize(target, relative_to):
    """Return a relative path to `target` from `relative_to`.

    Args:
      target: string, path to directory we want to get relative path to.
      relative_to: string, path to directory from which we are starting.

    Returns:
      string: relative path to `target`.
    """
    t_pieces = target.split("/")
    r_pieces = relative_to.split("/")
    common_part_len = 0

    for tp, rp in zip(t_pieces, r_pieces):
        if tp == rp:
            common_part_len += 1
        else:
            break

    result = [".."] * (len(r_pieces) - common_part_len)
    result += t_pieces[common_part_len:]

    return "/".join(result)