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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 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)