STY: fix flake8 whitespace and blank line errors

Author: Omesh37

pvlib/irradiance.py

@@ -1984,7 +1984,7 @@ def dirint(ghi, solar_zenith, times, pressure=101325., use_delta_kt_prime=True,
        SERI/TR-215-3087, Golden, CO: Solar Energy Research Institute, 1987.
     """
     scalar_input = np.isscalar(solar_zenith)
-    
+
     disc_out = disc(ghi, solar_zenith, times, pressure=pressure,
                     min_cos_zenith=min_cos_zenith, max_zenith=max_zenith)
     airmass = disc_out['airmass']
@@ -1999,7 +1999,6 @@ def dirint(ghi, solar_zenith, times, pressure=101325., use_delta_kt_prime=True,
     dirint_coeffs = _dirint_coeffs(times, kt_prime, solar_zenith, w,
                                    delta_kt_prime)
 
-
     # Perez eqn 5
     dni = disc_out['dni'] * dirint_coeffs
 
@@ -2164,7 +2163,6 @@ def _dirint_bins(times, kt_prime, zenith, w, delta_kt_prime):
     return kt_prime_bin, zenith_bin, w_bin, delta_kt_prime_bin
 
 
-    
 def dirindex(ghi, ghi_clear, dni_clear, zenith, times, pressure=101325.,
              use_delta_kt_prime=True, temp_dew=None, min_cos_zenith=0.065,
              max_zenith=87):

tests/test_irradiance.py

@@ -1139,6 +1139,7 @@ def test_dirindex_min_cos_zenith_max_zenith():
     expected = pd.Series([nan, 5.], index=times)
     assert_series_equal(out, expected)
 
+
 def test_dirint_scalar_inputs():
     """Scalar numeric inputs return scalar float output. GH #2751"""
     times = pd.DatetimeIndex(['2023-06-21 12:00'], tz='UTC')
@@ -1168,6 +1169,7 @@ def test_dirint_scalar_inputs():
     )
     assert isinstance(result_series, pd.Series)
 
+
 def test_dni():
     ghi = pd.Series([90, 100, 100, 100, 100])
     dhi = pd.Series([100, 90, 50, 50, 50])