diff --git a/demo/seqToseq/dataprovider.py b/demo/seqToseq/dataprovider.py
index 0614d54aaf8bb64f8a4d4a8af364fb993fd8cc7e..5174092df26089bc5661a7d98da62dc7a124c54d 100755
--- a/demo/seqToseq/dataprovider.py
+++ b/demo/seqToseq/dataprovider.py
@@ -25,11 +25,17 @@ def hook(settings, src_dict_path, trg_dict_path, is_generating, file_list,
     # job_mode = 0: generating mode
     settings.job_mode = not is_generating
     settings.src_dict = dict()
-    for line_count, line in enumerate(open(src_dict_path, "r")):
-        settings.src_dict[line.strip()] = line_count
+    with open(src_dict_path, "r") as fin:
+        settings.src_dict = {
+            line.strip(): line_count
+            for line_count, line in enumerate(fin)
+        }
     settings.trg_dict = dict()
-    for line_count, line in enumerate(open(trg_dict_path, "r")):
-        settings.trg_dict[line.strip()] = line_count
+    with open(trg_dict_path, "r") as fin:
+        settings.trg_dict = {
+            line.strip(): line_count
+            for line_count, line in enumerate(fin)
+        }
 
     settings.logger.info("src dict len : %d" % (len(settings.src_dict)))
     settings.sample_count = 0