diff --git a/ctr/reader.py b/ctr/reader.py
index d511b9d7c3b3a843b1e2819481b377ba5a49ce1a..cafa2349ed0e51a8de65dbeeea8b345edcf0a879 100644
--- a/ctr/reader.py
+++ b/ctr/reader.py
@@ -4,50 +4,48 @@ feeding_index = {'dnn_input': 0, 'lr_input': 1, 'click': 2}
 
 
 class Dataset(object):
-    def __init__(self):
-        self.mode = TaskMode.create_train()
-
     def train(self, path):
         '''
         Load trainset.
         '''
         logger.info("load trainset from %s" % path)
-        self.mode = TaskMode.create_train()
-        self.path = path
-        return self._parse
+        mode = TaskMode.create_train()
+        return self._parse_creator(path, mode)
 
     def test(self, path):
         '''
         Load testset.
         '''
         logger.info("load testset from %s" % path)
-        self.path = path
-        self.mode = TaskMode.create_test()
-        return self._parse
+        mode = TaskMode.create_test()
+        return self._parse_creator(path, mode)
 
     def infer(self, path):
         '''
         Load infer set.
         '''
         logger.info("load inferset from %s" % path)
-        self.path = path
-        self.mode = TaskMode.create_infer()
-        return self._parse
+        mode = TaskMode.create_infer()
+        return self._parse_creator(path, mode)
 
-    def _parse(self):
+    def _parse_creator(self, path, mode):
         '''
         Parse dataset.
         '''
-        with open(self.path) as f:
-            for line_id, line in enumerate(f):
-                fs = line.strip().split('\t')
-                dnn_input = load_dnn_input_record(fs[0])
-                lr_input = load_lr_input_record(fs[1])
-                if not self.mode.is_infer():
-                    click = [int(fs[2])]
-                    yield dnn_input, lr_input, click
-                else:
-                    yield dnn_input, lr_input
+
+        def _parse():
+            with open(path) as f:
+                for line_id, line in enumerate(f):
+                    fs = line.strip().split('\t')
+                    dnn_input = load_dnn_input_record(fs[0])
+                    lr_input = load_lr_input_record(fs[1])
+                    if not mode.is_infer():
+                        click = [int(fs[2])]
+                        yield dnn_input, lr_input, click
+                    else:
+                        yield dnn_input, lr_input
+
+        return _parse
 
 
 def load_data_meta(path):