Show tooltip with full path only for the root directory

def data(self, index, role):
        """Show tooltip with full path only for the root directory"""
        if role == Qt.ToolTipRole:
            root_dir = self.path_list[0].split(osp.sep)[-1]
            if index.data() == root_dir:
                return osp.join(self.root_path, root_dir)
        return QSortFilterProxyModel.data(self, index, role)