diff --git a/python/paddle/v2/fluid/clip.py b/python/paddle/v2/fluid/clip.py
index 777a39e105c0e96fefb8f9ab0647e1cbf895bbe4..386df9823de9119287abf87569eab0b283ecc802 100644
--- a/python/paddle/v2/fluid/clip.py
+++ b/python/paddle/v2/fluid/clip.py
@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 import functools
 import layers
 import framework
diff --git a/python/paddle/v2/fluid/layers/ops.py b/python/paddle/v2/fluid/layers/ops.py
index 7e52dc4c34f2987530b97f6d3a45d35fa8f361bc..d29607616266973b3e59dbae660724d0c3874def 100644
--- a/python/paddle/v2/fluid/layers/ops.py
+++ b/python/paddle/v2/fluid/layers/ops.py
@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 from ..registry import register_layer
 
 __activations__ = [
diff --git a/python/paddle/v2/fluid/param_attr.py b/python/paddle/v2/fluid/param_attr.py
index 17fcb262efb3d579038e07ce1d787282224f6f96..dcca8b6c547d10864ff4cd0af1c217d89e3b522f 100644
--- a/python/paddle/v2/fluid/param_attr.py
+++ b/python/paddle/v2/fluid/param_attr.py
@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 from initializer import Initializer, Xavier, Constant
 from regularizer import WeightDecayRegularizer
 
diff --git a/python/paddle/v2/fluid/tests/book/test_recognize_digits_mlp.py b/python/paddle/v2/fluid/tests/book/test_recognize_digits_mlp.py
index 2fde3707da35a3634f0d973830c5a86d0c7cd678..8776a65bf804e93dfeb295ecca34fac0840b0a90 100644
--- a/python/paddle/v2/fluid/tests/book/test_recognize_digits_mlp.py
+++ b/python/paddle/v2/fluid/tests/book/test_recognize_digits_mlp.py
@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 from __future__ import print_function
 import numpy as np
 import paddle.v2 as paddle
diff --git a/python/paddle/v2/fluid/tests/test_gradient_clip.py b/python/paddle/v2/fluid/tests/test_gradient_clip.py
index 75c5fd98925b677c3c786b84d6a0f1b589d0c369..4e6e6a1ef6961d8f087dfc1ac5a4c4a8ad90032e 100644
--- a/python/paddle/v2/fluid/tests/test_gradient_clip.py
+++ b/python/paddle/v2/fluid/tests/test_gradient_clip.py
@@ -11,6 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 import numpy as np
 import paddle.v2 as paddle
 import paddle.v2.fluid as fluid