code: def plot_or_print(my_turbine, e126, dummy_turbine):
      r
  
      # plot or print turbine power output
      if plt:
          e126.power_output.plot(legend=True, label='Enercon E126')
          my_turbine.power_output.plot(legend=True, label='myTurbine')
          dummy_turbine.power_output.plot(legend=True, label='dummyTurbine')
          plt.show()
      else:
          print(e126.power_output)
          print(my_turbine.power_output)
          print(dummy_turbine.power_output)
  
      # plot or print power curve
      if plt:
          if e126.power_curve is not None:
              e126.power_curve.plot(x='wind_speed', y='value', style='*',
                                    title='Enercon E126 power curve')
              plt.show()
          if my_turbine.power_curve is not None:
              my_turbine.power_curve.plot(x='wind_speed', y='value', style='*',
                                          title='myTurbine power curve')
              plt.show()
          if dummy_turbine.power_coefficient_curve is not None:
              dummy_turbine.power_coefficient_curve.plot(
                  x='wind_speed', y='value', style='*',
                  title='dummyTurbine power coefficient curve')
              plt.show()
      else:
          if e126.power_coefficient_curve is not None:
              print(e126.power_coefficient_curve)
          if e126.power_curve is not None:
              print(e126.power_curve)
docs: r"""
      Plots or prints power output and power (coefficient) curves.
  
      Parameters
      ----------
      my_turbine : WindTurbine
          WindTurbine object with self provided power curve.
      e126 : WindTurbine
          WindTurbine object with power curve from data file provided by the
          windpowerlib.
      dummy_turbine : WindTurbine
          WindTurbine object with power coefficient curve from example file.