diff --git a/mmdet3d/ops/group_points/group_points.py b/mmdet3d/ops/group_points/group_points.py
index 961285d749..0430aa65e6 100644
--- a/mmdet3d/ops/group_points/group_points.py
+++ b/mmdet3d/ops/group_points/group_points.py
@@ -1,4 +1,5 @@
 # Copyright (c) OpenMMLab. All rights reserved.
+
 from typing import Tuple
 
 import torch
diff --git a/tests/test_models/test_common_modules/test_pointnet_ops.py b/tests/test_models/test_common_modules/test_pointnet_ops.py
index ec3a581e63..30ad69b5d6 100644
--- a/tests/test_models/test_common_modules/test_pointnet_ops.py
+++ b/tests/test_models/test_common_modules/test_pointnet_ops.py
@@ -2,16 +2,9 @@
 import pytest
 import torch
 
-from mmdet3d.ops import (
-    ball_query,
-    furthest_point_sample,
-    furthest_point_sample_with_dist,
-    gather_points,
-    grouping_operation,
-    knn,
-    three_interpolate,
-    three_nn,
-)
+from mmdet3d.ops import (ball_query, furthest_point_sample,
+                         furthest_point_sample_with_dist, gather_points,
+                         grouping_operation, knn, three_interpolate, three_nn)
 
 
 def test_fps():