diff --git a/python/paddle/fluid/layers/control_flow.py b/python/paddle/fluid/layers/control_flow.py
index 7e541efcfca8cb9d4fb4b7edf769e25018348d7f..227919771705f2cab6a99c519ef3058108a5d73e 100644
--- a/python/paddle/fluid/layers/control_flow.py
+++ b/python/paddle/fluid/layers/control_flow.py
@@ -1218,6 +1218,7 @@ class IfElse(object):
 
     Examples:
           .. code-block:: python
+
             limit = layers.fill_constant_batch_size_like(
                 input=label, dtype='int64', shape=[1], value=5.0)
             cond = layers.less_than(x=label, y=limit)
diff --git a/python/paddle/fluid/layers/io.py b/python/paddle/fluid/layers/io.py
index df264e4f26dc8b8a430d889068f1e3d0e7abc127..f3aeb6cd757a3c40f04b08e61cfd5ce09908f92c 100644
--- a/python/paddle/fluid/layers/io.py
+++ b/python/paddle/fluid/layers/io.py
@@ -596,6 +596,7 @@ class Preprocessor(object):
 
     Examples:
           .. code-block:: python
+
             preprocessor = fluid.layers.io.Preprocessor(reader=reader)
             with preprocessor.block():
                 img, lbl = preprocessor.inputs()