diff --git a/python/paddle/fluid/optimizer.py b/python/paddle/fluid/optimizer.py
index 43d83b0f1f7a543e752ef0054f5765799a4db075..7b51e5d09f823a9e0b276e12f3d366c161ee828e 100644
--- a/python/paddle/fluid/optimizer.py
+++ b/python/paddle/fluid/optimizer.py
@@ -70,6 +70,7 @@ class Optimizer(object):
         # {accum_name : { paramter_name : accumulator_for_parameter, ...}, ...}
         self._accumulators = defaultdict(lambda: dict())
         self.helper = None
+
         self._opti_name_list = []
 
     def get_opti_var_name_list(self):