code: def _get_label(self, axis):
          
  
          if axis == 'x':
              colname = self.x_col
          else:  # y
              colname = self.y_col
  
          if colname == self._idxname:
              label = 'Index'
          else:
              col = self.tab[colname]
              if col.unit:
                  label = '{0} ({1})'.format(col.name, col.unit)
              else:
                  label = col.name
  
          return label
docs: Return plot label for column for the given axis.