Formatting adjusted by black.

Konrad0 · Konrad0 · commit ed967c724619 · 2021-07-06T20:57:21.000+02:00
diff --git a/sklearn/ensemble/_iforest.py b/sklearn/ensemble/_iforest.py
@@ -486,25 +486,62 @@ def _more_tags(self):
         }
 
 
-_average_path_length_small = np.array((
-    0.0, 0.0, 1.0,
-    1.6666666666666666667, 2.1666666666666666667, 2.5666666666666666667,
-    2.9000000000000000000, 3.1857142857142857143, 3.4357142857142857143,
-    3.6579365079365079365, 3.8579365079365079365, 4.0397546897546897547,
-    4.2064213564213564214, 4.3602675102675102675, 4.5031246531246531247,
-    4.6364579864579864580, 4.7614579864579864580, 4.8791050452815158698,
-    4.9902161563926269809, 5.0954793142873638230, 5.1954793142873638230,
-    5.2907174095254590611, 5.3816265004345499702, 5.4685830221736804049,
-    5.5519163555070137383, 5.6319163555070137383, 5.7088394324300906613,
-    5.7829135065041647354, 5.8543420779327361640, 5.9233075951741154743,
-    5.9899742618407821410, 6.0544903908730402055, 6.1169903908730402055,
-    6.1775964514791008116, 6.2364199808908655175, 6.2935628380337226603,
-    6.3491183935892782159, 6.4031724476433322699, 6.4558040265907006910,
-    6.5070860778727519730, 6.5570860778727519730, 6.6058665656776300218,
-    6.6534856132966776409, 6.6999972412036543850, 6.7454517866581998396,
-    6.7898962311026442840, 6.8333744919722095014, 6.8759276834615712036,
-    6.9175943501282378702, 6.9584106766588501151, 6.9984106766588501151,
-    7.0376263629333599190))
+_average_path_length_small = np.array(
+    (
+        0.0,
+        0.0,
+        1.0,
+        1.6666666666666666667,
+        2.1666666666666666667,
+        2.5666666666666666667,
+        2.9000000000000000000,
+        3.1857142857142857143,
+        3.4357142857142857143,
+        3.6579365079365079365,
+        3.8579365079365079365,
+        4.0397546897546897547,
+        4.2064213564213564214,
+        4.3602675102675102675,
+        4.5031246531246531247,
+        4.6364579864579864580,
+        4.7614579864579864580,
+        4.8791050452815158698,
+        4.9902161563926269809,
+        5.0954793142873638230,
+        5.1954793142873638230,
+        5.2907174095254590611,
+        5.3816265004345499702,
+        5.4685830221736804049,
+        5.5519163555070137383,
+        5.6319163555070137383,
+        5.7088394324300906613,
+        5.7829135065041647354,
+        5.8543420779327361640,
+        5.9233075951741154743,
+        5.9899742618407821410,
+        6.0544903908730402055,
+        6.1169903908730402055,
+        6.1775964514791008116,
+        6.2364199808908655175,
+        6.2935628380337226603,
+        6.3491183935892782159,
+        6.4031724476433322699,
+        6.4558040265907006910,
+        6.5070860778727519730,
+        6.5570860778727519730,
+        6.6058665656776300218,
+        6.6534856132966776409,
+        6.6999972412036543850,
+        6.7454517866581998396,
+        6.7898962311026442840,
+        6.8333744919722095014,
+        6.8759276834615712036,
+        6.9175943501282378702,
+        6.9584106766588501151,
+        6.9984106766588501151,
+        7.0376263629333599190,
+    )
+)
 
 
 def _average_path_length(n_samples_leaf):
@@ -533,7 +570,8 @@ def _average_path_length(n_samples_leaf):
     not_mask = ~mask_small
 
     average_path_length[mask_small] = _average_path_length_small[
-        n_samples_leaf[mask_small]]
+        n_samples_leaf[mask_small]
+    ]
 
     # Average path length equals 2*(H(n)-1), with H(n) the nth harmonic number.
     # For the harmonic number calculation,
@@ -546,11 +584,11 @@ def _average_path_length(n_samples_leaf):
     # Wang, W. Harmonic Number Expansions of the Ramanujan Type.
     # Results Math 73, 161 (2018). https://doi.org/10.1007/s00025-018-0920-8
 
-    tmp = 1.0/np.square(n_samples_leaf[not_mask])
+    tmp = 1.0 / np.square(n_samples_leaf[not_mask])
     average_path_length[not_mask] = (
         2.0 * (np.log(n_samples_leaf[not_mask]) - 1.0 + np.euler_gamma)
-        + 1.0/n_samples_leaf[not_mask]
-        - tmp*(1.0/6.0 - tmp*(1.0/60.0 - tmp/126.0))
+        + 1.0 / n_samples_leaf[not_mask]
+        - tmp * (1.0 / 6.0 - tmp * (1.0 / 60.0 - tmp / 126.0))
     )
 
     return average_path_length.reshape(n_samples_leaf_shape)
diff --git a/sklearn/ensemble/tests/test_iforest.py b/sklearn/ensemble/tests/test_iforest.py
@@ -230,7 +230,7 @@ def test_iforest_average_path_length():
     # It tests non-regression for #8549 which used the wrong formula
     # for average path length, strictly for the integer case
     # Updated to check average path length when input is <= 2 (issue #11839)
-    result_5 = 77.0/30.0
+    result_5 = 77.0 / 30.0
     result_999 = 12.9689417211006898253130364
     assert_allclose(_average_path_length([0]), [0.0])
     assert_allclose(_average_path_length([1]), [0.0])
