diff --git a/python/paddle/fluid/tests/unittests/test_sum_op.py b/python/paddle/fluid/tests/unittests/test_sum_op.py
index 3c42607918209af7bba9c2ba94aab5d521944588..81efd01d5073184477dbeb9b9ed6b3cff741bef4 100644
--- a/python/paddle/fluid/tests/unittests/test_sum_op.py
+++ b/python/paddle/fluid/tests/unittests/test_sum_op.py
@@ -50,11 +50,16 @@ class TestSelectedRowsSumOp(OpTest):
         self.check_input_and_optput(scope, place, False, False, True)
         self.check_input_and_optput(scope, place, False, False, False)
 
-    def check_input_and_optput(self, scope, place, w1=False, w2=False,
-                               w3=False):
-        W1 = self.create_selected_rows(scope, place, "W1", w1)
-        W2 = self.create_selected_rows(scope, place, "W2", w2)
-        W3 = self.create_selected_rows(scope, place, "W3", w3)
+    def check_input_and_optput(self,
+                               scope,
+                               place,
+                               w1_has_data=False,
+                               w2_has_data=False,
+                               w3_has_data=False):
+
+        self.create_selected_rows(scope, place, "W1", w1_has_data)
+        self.create_selected_rows(scope, place, "W2", w2_has_data)
+        self.create_selected_rows(scope, place, "W3", w3_has_data)
 
         # create Out Variable
         out = scope.var('Out').get_selected_rows()
@@ -63,12 +68,12 @@ class TestSelectedRowsSumOp(OpTest):
         sum_op = Operator("sum", X=["W1", "W2", "W3"], Out='Out')
         sum_op.run(scope, place)
 
-        trues = 0
-        for w in [w1, w2, w3]:
+        has_data_w_num = 0
+        for w in [w1_has_data, w2_has_data, w3_has_data]:
             if not w:
-                trues += 1
+                has_data_w_num += 1
 
-        self.assertEqual(7 * trues, len(out.rows()))
+        self.assertEqual(7 * has_data_w_num, len(out.rows()))
 
     def create_selected_rows(self, scope, place, var_name, isEmpty):
         # create and initialize W Variable