fix unicode error in TaggedItem.__str__ on py2

this was caused by trying to format unicode data into
a byte string

Author: sk1p

tagging/models.py

@@ -4,7 +4,7 @@
 from django.contrib.contenttypes import generic
 from django.contrib.contenttypes.models import ContentType
 from django.db import connection, models
-from django.utils.encoding import python_2_unicode_compatible
+from django.utils.encoding import python_2_unicode_compatible, smart_text
 from django.utils.translation import ugettext_lazy as _
 
 from . import settings
@@ -487,4 +487,4 @@ class Meta:
         verbose_name_plural = _('tagged items')
 
     def __str__(self):
-        return '%s [%s]' % (self.object, self.tag)
+        return '%s [%s]' % (smart_text(self.object), smart_text(self.tag))

tagging/tests/tests.py

@@ -6,6 +6,7 @@
 from django import forms
 from django.db.models import Q
 from django.test import TestCase
+from django.utils import six
 
 from tagging import settings
 from tagging.forms import TagField
@@ -333,7 +334,7 @@ def test_unicode_tagged_object(self):
         Tag.objects.update_tags(self.dead_parrot, u'föo')
         items = TaggedItem.objects.all()
         self.assertEqual(len(items), 1)
-        self.assertEqual(unicode(items[0]), u"dëad [föo]")
+        self.assertEqual(six.text_type(items[0]), u"dëad [föo]")
 
     def test_update_tags_with_none(self):
         # start off in a known, mildly interesting state