code: def get_value(self, index):
          
          p = index.internalPointer()
          k = self.get_key(p, index.row())
          return p[k]
docs: Return the value of the given index
  
          The index stores the section as internal pointer.
          The row of the index determines the key.
          The key is used on the section to return the value
  
          :param index: The QModelIndex
          :type index: QModelIndex
          :returns: The value for the given index