def to_algebraic(cartesian):
    """Convert cartesian to algebraic

    Parameters
    ----------
    cartesian: tuple
        Cartesian coordinate

    Returns
    -------
    str
        Algebraic coordinate

    """
    mapper = {
        1: 'A',
        2: 'B',
        3: 'C',
        4: 'D',
        5: 'E',
        6: 'F',
        7: 'G',
        8: 'H'}

    file_ = mapper[cartesian[0]]
    rank_ = str(cartesian[1])

    return file_ + rank_