code: def rowCount(self, parent=None):
          
          if self._separateFieldOrientation == Qt.Vertical:
              return self._nRows * len(self._fieldNames)
          else:
              return self._nRows
docs: The number of rows of the sliced array.
              The 'parent' parameter can be a QModelIndex. It is ignored since the number of
              rows does not depend on the parent.