diff --git a/deeplink_ext/ascend_speed/_rotary_embedding_npu.py b/deeplink_ext/ascend_speed/_rotary_embedding_npu.py
index 646f7e9..a8f8226 100644
--- a/deeplink_ext/ascend_speed/_rotary_embedding_npu.py
+++ b/deeplink_ext/ascend_speed/_rotary_embedding_npu.py
@@ -27,4 +27,8 @@ def forward(ctx, x, cos, sin):
     @staticmethod
     def backward(ctx, grad_output):
         out, cos, sin = ctx.saved_tensors
-        return torch_npu.npu_rotary_mul_backward(grad_output, out, cos, sin)[0], None, None
+        return (
+            torch_npu.npu_rotary_mul_backward(grad_output, out, cos, sin)[0],
+            None,
+            None
+        )
diff --git a/tests/conftest.py b/tests/conftest.py
index cd2aae5..6d3a6f5 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -3,6 +3,7 @@
 
 from deeplink_ext.utils import PlatformType, deeplink_ext_get_platform_type
 
+
 @pytest.fixture(scope='session', autouse=True)
 def import_module():
     platform = deeplink_ext_get_platform_type()