show a value assocciated with an attribute for each
    DataProperty instance in the dp_matrix

def display_dp_matrix_attr(dp_matrix, attr_name):
    """
    show a value assocciated with an attribute for each
    DataProperty instance in the dp_matrix
    """

    print()
    print("---------- {:s} ----------".format(attr_name))
    for dp_list in dp_matrix:
        print([getattr(dp, attr_name) for dp in dp_list])