Port new code to Python 3 as well, fix six.with_metaclass() issues

Many thanks to @atheiste for the big porting steps!

.travis.yml

@@ -2,6 +2,7 @@ language: python
 python:
   - "2.6"
   - "2.7"
+  - "3.3"
 env:
   - DJANGO=django==1.4.5
   - DJANGO=django==1.5

polymorphic/base.py

@@ -54,6 +54,13 @@ class PolymorphicModelBase(ModelBase):
     def __new__(self, model_name, bases, attrs):
         #print; print '###', model_name, '- bases:', bases
 
+        # Workaround compatibility issue with six.with_metaclass() and custom Django model metaclasses:
+        # Let Django fully ignore the class which is inserted in between.
+        if not attrs and model_name == 'NewBase':
+            attrs['__module__'] = 'django.utils.six'
+            attrs['Meta'] = type('Meta', (), {'abstract': True})
+            return super(PolymorphicModelBase, self).__new__(self, model_name, bases, attrs)
+
         # create new model
         new_class = self.call_superclass_new_method(model_name, bases, attrs)
 
@@ -145,7 +152,7 @@ class PolymorphicModelBase(ModelBase):
         # The ordering in the base.__dict__ may randomly change depending on which method is added.
         # Make sure base_objects is on top, and 'objects' and '_default_manager' follow afterwards.
         # This makes sure that the _base_manager is also assigned properly.
-        add_managers = sorted(add_managers, key=lambda item: item[2].creation_counter, reverse=True)
+        add_managers = sorted(add_managers, key=lambda item: (item[1].startswith('_'), item[1]))
         return add_managers
 
     @classmethod
@@ -178,9 +185,8 @@ class PolymorphicModelBase(ModelBase):
         # which is directly in the python path. To work around this we temporarily set
         # app_label here for PolymorphicModel.
         meta = attrs.get('Meta', None)
-        model_module_name = attrs['__module__']
         do_app_label_workaround = (meta
-                                    and model_module_name == 'polymorphic'
+                                    and attrs['__module__'] == 'polymorphic'
                                     and model_name == 'PolymorphicModel'
                                     and getattr(meta, 'app_label', None) is None)
 

polymorphic/query_translate.py

@@ -34,7 +34,7 @@ def translate_polymorphic_filter_definitions_in_kwargs(queryset_model, kwargs):
     Returns: a list of non-keyword-arguments (Q objects) to be added to the filter() query.
     """
     additional_args = []
-    for field_path, val in kwargs.items():
+    for field_path, val in kwargs.copy().items():  # Python 3 needs copy
 
         new_expr = _translate_polymorphic_filter_definition(queryset_model, field_path, val)
 

polymorphic/tests.py

@@ -2,6 +2,7 @@
 """ Test Cases
     Please see README.rst or DOCS.rst or http://chrisglass.github.com/django_polymorphic/
 """
+from __future__ import print_function
 import uuid
 import re
 from django.db.models.query import QuerySet
@@ -10,6 +11,7 @@ from django.test import TestCase
 from django.db.models import Q,Count
 from django.db import models
 from django.contrib.contenttypes.models import ContentType
+from django.utils import six
 
 from polymorphic import PolymorphicModel, PolymorphicManager, PolymorphicQuerySet
 from polymorphic import ShowFieldContent, ShowFieldType, ShowFieldTypeAndContent
@@ -253,10 +255,10 @@ class PolymorphicTests(TestCase):
         o2 = DiamondXY.objects.get()
 
         if o2.field_b != 'b':
-            print
+            print('')
-            print '# known django model inheritance diamond problem detected'
+            print('# known django model inheritance diamond problem detected')
-            print 'DiamondXY fields 1: field_b "{0}", field_x "{1}", field_y "{2}"'.format(o1.field_b, o1.field_x, o1.field_y)
+            print('DiamondXY fields 1: field_b "{0}", field_x "{1}", field_y "{2}"'.format(o1.field_b, o1.field_x, o1.field_y))
-            print 'DiamondXY fields 2: field_b "{0}", field_x "{1}", field_y "{2}"'.format(o2.field_b, o2.field_x, o2.field_y)
+            print('DiamondXY fields 2: field_b "{0}", field_x "{1}", field_y "{2}"'.format(o2.field_b, o2.field_x, o2.field_y))
 
 
     def test_annotate_aggregate_order(self):
@@ -363,16 +365,16 @@ class PolymorphicTests(TestCase):
   <UUIDResearchProject: uuid_primary_key (UUIDField/pk), topic (CharField) "Swallow Aerodynamics", supervisor (CharField) "Dr. Winter"> ]"""
         self.assertEqual(res, res_exp)
         #if (a.pk!= uuid.UUID or c.pk!= uuid.UUID):
-        #    print
+        #    print()
-        #    print '# known inconstency with custom primary key field detected (django problem?)'
+        #    print('# known inconstency with custom primary key field detected (django problem?)')
 
         a = UUIDPlainA.objects.create(field1='A1')
         b = UUIDPlainB.objects.create(field1='B1', field2='B2')
         c = UUIDPlainC.objects.create(field1='C1', field2='C2', field3='C3')
         qs = UUIDPlainA.objects.all()
         if a.pk!= uuid.UUID or c.pk!= uuid.UUID:
-            print
+            print('')
-            print '# known type inconstency with custom primary key field detected (django problem?)'
+            print('# known type inconstency with custom primary key field detected (django problem?)')
 
 
     def create_model2abcd(self):
@@ -531,9 +533,14 @@ class PolymorphicTests(TestCase):
         ModelExtraExternal.objects.create(topic='extra2')
         ModelExtraExternal.objects.create(topic='extra3')
         objects = ModelExtraA.objects.extra(tables=["polymorphic_modelextraexternal"], select={"topic":"polymorphic_modelextraexternal.topic"}, where=["polymorphic_modelextraa.id = polymorphic_modelextraexternal.id"])
-        self.assertEqual(repr(objects[0]), '<ModelExtraA: id 1, field1 (CharField) "A1" - Extra: topic (unicode) "extra1">')
+        if six.PY3:
-        self.assertEqual(repr(objects[1]), '<ModelExtraB: id 2, field1 (CharField) "B1", field2 (CharField) "B2" - Extra: topic (unicode) "extra2">')
+            self.assertEqual(repr(objects[0]), '<ModelExtraA: id 1, field1 (CharField) "A1" - Extra: topic (str) "extra1">')
-        self.assertEqual(repr(objects[2]), '<ModelExtraC: id 3, field1 (CharField) "C1", field2 (CharField) "C2", field3 (CharField) "C3" - Extra: topic (unicode) "extra3">')
+            self.assertEqual(repr(objects[1]), '<ModelExtraB: id 2, field1 (CharField) "B1", field2 (CharField) "B2" - Extra: topic (str) "extra2">')
+            self.assertEqual(repr(objects[2]), '<ModelExtraC: id 3, field1 (CharField) "C1", field2 (CharField) "C2", field3 (CharField) "C3" - Extra: topic (str) "extra3">')
+        else:
+            self.assertEqual(repr(objects[0]), '<ModelExtraA: id 1, field1 (CharField) "A1" - Extra: topic (unicode) "extra1">')
+            self.assertEqual(repr(objects[1]), '<ModelExtraB: id 2, field1 (CharField) "B1", field2 (CharField) "B2" - Extra: topic (unicode) "extra2">')
+            self.assertEqual(repr(objects[2]), '<ModelExtraC: id 3, field1 (CharField) "C1", field2 (CharField) "C2", field3 (CharField) "C3" - Extra: topic (unicode) "extra3">')
         self.assertEqual(len(objects), 3)
 
 

polymorphic/tools_for_tests.py

@@ -6,7 +6,7 @@ import uuid
 
 from django import forms
 from django.db import models
-from django.utils.encoding import smart_unicode
+from django.utils.encoding import smart_text
 from django.utils import six
 
 class UUIDVersionError(Exception):
@@ -98,7 +98,7 @@ class UUIDField(six.with_metaclass(models.SubfieldBase, models.CharField)):
         if isinstance(value, uuid.UUID):
             return value
         # attempt to parse a UUID
-        return uuid.UUID(smart_unicode(value))
+        return uuid.UUID(smart_text(value))
 
         #
         # If I do the following (returning a String instead of a UUID
@@ -108,7 +108,7 @@ class UUIDField(six.with_metaclass(models.SubfieldBase, models.CharField)):
         #if not value:
         # return None
         #if isinstance(value, uuid.UUID):
-        # return smart_unicode(value)
+        # return smart_text(value)
         #else:
         # return value
 
@@ -126,7 +126,7 @@ class UUIDField(six.with_metaclass(models.SubfieldBase, models.CharField)):
     def get_db_prep_value(self, value, connection, prepared):
         """Casts uuid.UUID values into the format expected by the back end for use in queries"""
         if isinstance(value, uuid.UUID):
-            return smart_unicode(value)
+            return smart_text(value)
         return value
 
     def value_to_string(self, obj):
@@ -134,7 +134,7 @@ class UUIDField(six.with_metaclass(models.SubfieldBase, models.CharField)):
         if val is None:
             data = ''
         else:
-            data = smart_unicode(val)
+            data = smart_text(val)
         return data
 
     def formfield(self, **kwargs):

tox.ini

@@ -1,5 +1,6 @@
 [tox]
 envlist=
+    py33-django15,
     py26-django15,
     py27-django15,
     py26-django14,
@@ -31,3 +32,8 @@ basepython=python2.7
 deps=
     django==1.4.5
 
+[testenv:py33-django15]
+basepython=python3.3
+deps=
+    django==1.5
+