Use BytesIO instead of StringIO. Use text_type instead of unicode.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/converter/classes.py

@@ -1,18 +1,15 @@
 from __future__ import unicode_literals
 
 import base64
+from io import BytesIO
 import logging
 import os
 
-try:
-    from cStringIO import StringIO
-except ImportError:
-    from StringIO import StringIO
-
 from PIL import Image, ImageFilter
 import sh
 import yaml
 
+from django.utils.six import text_type
 from django.utils.translation import string_concat, ugettext_lazy as _
 
 from common.settings import setting_temporary_directory
@@ -193,7 +190,7 @@ class ConverterBase(object):
         if not self.image:
             self.seek(0)
 
-        image_buffer = StringIO()
+        image_buffer = BytesIO()
         new_mode = self.image.mode
 
         if output_format.upper() == 'JPEG':
@@ -296,7 +293,7 @@ class BaseTransformation(object):
             self.kwargs[argument_name] = kwargs.get(argument_name)
 
     def cache_hash(self):
-        result = unicode.__hash__(self.name)
+        result = text_type.__hash__(self.name)
         for index, (key, value) in enumerate(self.kwargs.items()):
             result ^= hash((key, index)) ^ hash((value, index))