Fixed #18269 -- Applied unicode_literals for Python 3 compatibility.

Thanks Vinay Sajip for the support of his django3 branch and
Jannis Leidel for the review.

1 files changed, 2 insertions, 1 deletions

diff --git a/django/core/serializers/python.py b/django/core/serializers/python.py
index 49120434eb..333161c929 100644
--- a/django/core/serializers/python.py
+++ b/django/core/serializers/python.py
@@ -3,6 +3,7 @@ A Python "serializer". Doesn't do much serializing per se -- just converts to
 and from basic Python data types (lists, dicts, strings, etc.). Useful as a basis for
 other serializers.
 """
+from __future__ import unicode_literals
 
 from django.conf import settings
 from django.core.serializers import base
@@ -138,5 +139,5 @@ def _get_model(model_identifier):
     except TypeError:
         Model = None
     if Model is None:
-        raise base.DeserializationError(u"Invalid model identifier: '%s'" % model_identifier)
+        raise base.DeserializationError("Invalid model identifier: '%s'" % model_identifier)
     return Model