Merge pull request #3941 from qlzh727/3885-fix

Fix string to bytes conversion in deeplab data input. #3885

research/deeplab/datasets/build_data.py

@@ -30,6 +30,7 @@ The Example proto contains the following fields:
   image/segmentation/class/format: semantic segmentation file format.
 """
 import collections
+import six
 import tensorflow as tf
 
 FLAGS = tf.app.flags.FLAGS
@@ -126,7 +127,7 @@ def _bytes_list_feature(values):
     A TF-Feature.
   """
   def norm2bytes(value):
-      return value.encode() if isinstance(value, str) else value
+      return value.encode() if isinstance(value, str) and six.PY3 else value
 
   return tf.train.Feature(bytes_list=tf.train.BytesList(value=[norm2bytes(values)]))