fix io.open bug in word2vec (#3824)

* fix python3 reload bug

* fix io.open,test=release/1.6

PaddleRec/word2vec/utils.py

@@ -7,12 +7,13 @@ import paddle.fluid as fluid
 import paddle
 import os
 import preprocess
+import io
 
 
 def BuildWord_IdMap(dict_path):
     word_to_id = dict()
     id_to_word = dict()
-    with open(dict_path, 'r', encoding='utf-8') as f:
+    with io.open(dict_path, 'r', encoding='utf-8') as f:
         for line in f:
             word_to_id[line.split(' ')[0]] = int(line.split(' ')[1])
             id_to_word[int(line.split(' ')[1])] = line.split(' ')[0]
@@ -25,20 +26,22 @@ def prepare_data(file_dir, dict_path, batch_size):
     reader = fluid.io.batch(test(file_dir, w2i), batch_size)
     return vocab_size, reader, i2w
 
+
 def check_version():
-     """
+    """
      Log error and exit when the installed version of paddlepaddle is
      not satisfied.
      """
-     err = "PaddlePaddle version 1.6 or higher is required, " \
-           "or a suitable develop version is satisfied as well. \n" \
-           "Please make sure the version is good with your code." \
+    err = "PaddlePaddle version 1.6 or higher is required, " \
+          "or a suitable develop version is satisfied as well. \n" \
+          "Please make sure the version is good with your code." \
+
+    try:
+        fluid.require_version('1.6.0')
+    except Exception as e:
+        logger.error(err)
+        sys.exit(1)
 
-     try:
-         fluid.require_version('1.6.0')
-     except Exception as e:
-         logger.error(err)
-         sys.exit(1)
 
 def native_to_unicode(s):
     if _is_unicode(s):
@@ -89,7 +92,8 @@ def reader_creator(file_dir, word_to_id):
     def reader():
         files = os.listdir(file_dir)
         for fi in files:
-            with open(os.path.join(file_dir, fi), "r", encoding='utf-8') as f:
+            with io.open(
+                    os.path.join(file_dir, fi), "r", encoding='utf-8') as f:
                 for line in f:
                     if ':' in line:
                         pass