code: def index(self, row, column, parent):
          
          if not parent.isValid():
              s = self._conf
          else:
              p = parent.internalPointer()
              k = self.get_key(p, parent.row())
              s = p[k]
          return self.createIndex(row, column, s)
docs: Reimplemented from QtCore.QAbstractItemModel
  
          The internal pointer is the section.
          The row determines the key in the scalars then sections of the configobj.
          So for a given index, use row to retrieve the key::
  
            key = self.get_key(index.internalPointer(), index.row())
  
          To use the key on the section to get the value OR
          use get_value(index) / get_configspec_str