Fixing style errors.

Author: stickler-ci

windpowerlib/power_output.py

@@ -237,18 +237,37 @@ def power_curve_density_correction(
 
     """
     if density is None:
-        raise TypeError("`density` is None. For the calculation with a " +
-                        "density corrected power curve density at hub " +
-                        "height is needed.")
-    power_output=[(np.interp(
-        wind_speed[i], power_curve_wind_speeds * (1.225 / density[i]) ** (
-            np.interp(power_curve_wind_speeds, [7.5, 12.5], [1/3, 2/3])),
-        power_curve_values, left=0, right=0)) for i in range(len(wind_speed))]
+        raise TypeError(
+            "`density` is None. For the calculation with a "
+            + "density corrected power curve density at hub "
+            + "height is needed."
+        )
+    power_output = [
+        (
+            np.interp(
+                wind_speed[i],
+                power_curve_wind_speeds
+                * (1.225 / density[i])
+                ** (
+                    np.interp(
+                        power_curve_wind_speeds, [7.5, 12.5], [1 / 3, 2 / 3]
+                    )
+                ),
+                power_curve_values,
+                left=0,
+                right=0,
+            )
+        )
+        for i in range(len(wind_speed))
+    ]
 
     # Power_output as pd.Series if wind_speed is pd.Series (else: np.array)
     if isinstance(wind_speed, pd.Series):
-        power_output=pd.Series(data=power_output, index=wind_speed.index,
-                                 name='feedin_power_plant')
+        power_output = pd.Series(
+            data=power_output,
+            index=wind_speed.index,
+            name="feedin_power_plant",
+        )
     else:
-        power_output=np.array(power_output)
+        power_output = np.array(power_output)
     return power_output

windpowerlib/wind_speed.py

@@ -171,10 +171,11 @@ def hellman(
     if hellman_exponent is None:
         if roughness_length is not None:
             # Return np.array if wind_speed is np.array
-            if (isinstance(wind_speed, np.ndarray) and
-                    isinstance(roughness_length, pd.Series)):
-                roughness_length=np.array(roughness_length)
-            hellman_exponent=1 / np.log(hub_height / roughness_length)
+            if isinstance(wind_speed, np.ndarray) and isinstance(
+                roughness_length, pd.Series
+            ):
+                roughness_length = np.array(roughness_length)
+            hellman_exponent = 1 / np.log(hub_height / roughness_length)
         else:
-            hellman_exponent=1/7
+            hellman_exponent = 1 / 7
     return wind_speed * (hub_height / wind_speed_height) ** hellman_exponent