code: def sort(self, columnId, order=Qt.AscendingOrder):
          self.layoutAboutToBeChanged.emit()
          self.sortingAboutToStart.emit()
          column = self._dataFrame.columns[columnId]
          self._dataFrame.sort_values(column, ascending=not bool(order), inplace=True)
          self.layoutChanged.emit()
          self.sortingFinished.emit()