fix code

api/brand.py

@@ -26,12 +26,13 @@ class BrandListView(APIView):
 
         category_infos = self.rpc['neptune/commodity/category/infos'](brand_ids=brand_ids).unwrap()
         category_dict = {}
-        for obj in category_infos:
-            obj_id = obj.get('brand_id')
-            if category_dict.get(str(obj_id)):
-                category_dict.get(str(obj_id)).append(obj)
-            else:
-                category_dict[str(obj_id)] = [obj]
+        if category_infos:
+            for obj in category_infos:
+                obj_id = obj.get('brand_id')
+                if category_dict.get(str(obj_id)):
+                    category_dict.get(str(obj_id)).append(obj)
+                else:
+                    category_dict[str(obj_id)] = [obj]
 
         classify_infos = self.rpc['neptune/commodity/classify/infos'](brand_ids=brand_ids).unwrap()
         classify_dict = {str(obj.get('brand_id')): obj for obj in classify_infos}