code: def power_factor(self):
          
          if self._power_factor is None:
              if isinstance(self.grid, MVGrid):
                  self._power_factor = self.grid.network.config[
                      'reactive_power_factor']['mv_load']
              elif isinstance(self.grid, LVGrid):
                  self._power_factor = self.grid.network.config[
                      'reactive_power_factor']['lv_load']
          return self._power_factor
docs: Power factor of load
  
          Parameters
          -----------
          power_factor : :obj:`float`
              Ratio of real power to apparent power.
  
          Returns
          --------
          :obj:`float`
              Ratio of real power to apparent power. If power factor is not set
              it is retrieved from the network config object depending on the
              grid level the load is in.