diff --git a/elastic-ctr/client/demo/elastic_ctr.py b/elastic-ctr/client/demo/elastic_ctr.py
index 77ae6879979aa0e25ae84422c78d1e9023228979..75684052b19909aae53c7146d3de909605fd06c9 100644
--- a/elastic-ctr/client/demo/elastic_ctr.py
+++ b/elastic-ctr/client/demo/elastic_ctr.py
@@ -14,7 +14,6 @@
 
 from __future__ import print_function
 import json
-import httplib
 import sys
 import os
 
@@ -27,6 +26,13 @@ CTR_EMBEDDING_TABLE_SIZE = 400000001
 SLOTS = []
 
 
+def str2long(str):
+    if sys.version_info[0] == 2:
+        return long(str)
+    elif sys.version_info[0] == 3:
+        return int(str)
+
+
 def data_reader(data_file, samples, labels):
     if not os.path.exists(data_file):
         print("Path %s not exist" % data_file)
@@ -45,10 +51,14 @@ def data_reader(data_file, samples, labels):
 
             for i in range(0, len(features)):
                 if slots[i] in sample:
-                    sample[slots[i]] = [sample[slots[i]] + long(features[i])]
+                    sample[slots[i]] = [
+                        sample[slots[i]] + str2long(features[i]) %
+                        CTR_EMBEDDING_TABLE_SIZE
+                    ]
                 else:
-                    sample[slots[
-                        i]] = [long(features[i]) % CTR_EMBEDDING_TABLE_SIZE]
+                    sample[slots[i]] = [
+                        str2long(features[i]) % CTR_EMBEDDING_TABLE_SIZE
+                    ]
 
             for x in SLOTS:
                 if not x in sample:
@@ -85,8 +95,12 @@ if __name__ == "__main__":
         for sample in batch:
             instance = api.add_instance()
             kv = []
-            for k, v in sample.iteritems():
-                api.add_slot(instance, k, v)
+            if sys.version_info[0] == 2:
+                for k, v in sample.iteritems():
+                    api.add_slot(instance, k, v)
+            elif sys.version_info[0] == 3:
+                for k, v in sample.items():
+                    api.add_slot(instance, k, v)
 
         ret = api.inference()
         print(ret)