Update test_cross_entropy_loss.py

python/paddle/fluid/tests/unittests/test_cross_entropy_loss.py

@@ -1208,7 +1208,9 @@ class CrossEntropyLoss(unittest.TestCase):
             self.assertIsNotNone(static_ret)
         with fluid.dygraph.guard():
             cross_entropy_loss = paddle.nn.loss.CrossEntropyLoss(
-                weight=fluid.dygraph.to_variable(weight_np), reduction='mean', axis=1)
+                weight=fluid.dygraph.to_variable(weight_np),
+                reduction='mean',
+                axis=1)
             dy_ret = cross_entropy_loss(
                 fluid.dygraph.to_variable(input_np),
                 fluid.dygraph.to_variable(label_np))