be compatible with py3

ppcls/data/reader.py

@@ -189,9 +189,9 @@ def partial_reader(params, full_lines, part_id=0, part_num=1):
         for line in full_lines:
             img_path, label = line.split()
             img_path = os.path.join(params['data_dir'], img_path)
-            img = open(img_path).read()
-            img = transform(img, ops)
-            yield (img, int(label))
+            with open(img_path, 'rb') as f:
+                img = f.read()
+            yield (transform(img, ops), int(label))
 
     return reader