code: def _deleteSpinBoxes(self, row):
          
          tree = self.tree
          model = self.tree.model()
  
          for col, spinBox in enumerate(self._spinBoxes, self.COL_FIRST_COMBO + self.maxCombos):
              spinBox.valueChanged[int].disconnect(self._spinboxValueChanged)
              tree.setIndexWidget(model.index(row, col), None)
          self._spinBoxes = []
  
          self._setColumnCountForContents()
docs: Removes all spinboxes