Compatibility with Python 3.

wagtail_modeltranslation/apps.py

@@ -1,4 +1,6 @@
 # coding: utf-8
+from __future__ import absolute_import
+
 from django.apps import AppConfig
 
 
@@ -15,5 +17,5 @@ class ModeltranslationConfig(AppConfig):
         from modeltranslation.models import handle_translation_registrations
         handle_translation_registrations()
 
-        from patch_wagtailadmin import patch_wagtail_models
+        from .patch_wagtailadmin import patch_wagtail_models
         patch_wagtail_models()

wagtail_modeltranslation/patch_wagtailadmin.py

@@ -390,7 +390,7 @@ def patch_wagtail_models():
     # We need to sort the models to ensure that subclasses of a model are registered first,
     # or else if the panels are inherited all the changes on the subclass would be
     # reflected in the superclass
-    registered_models.sort(compare_class_tree_depth)
+    registered_models.sort(key=compare_class_tree_depth)
 
     for model_class in registered_models:
         if issubclass(model_class, Page) or model_class in get_snippet_models() or issubclass(model_class, BaseSetting):

wagtail_modeltranslation/templatetags/wagtail_modeltranslation.py

@@ -5,6 +5,7 @@ import re
 from django import template
 from django.core.urlresolvers import resolve
 from django.utils.translation import activate, get_language
+from six import iteritems
 
 register = template.Library()
 
@@ -37,7 +38,7 @@ def change_lang(context, lang=None, *args, **kwargs):
             translated_url = '/' + lang + '/' + path_components[0] + '/'
             if request.GET:
                 translated_url += '?'
-                for key, value in request.GET.iteritems():
+                for key, value in iteritems(request.GET):
                     translated_url += key + '=' + value
             return translated_url
 

wagtail_modeltranslation/tests/tests.py

@@ -10,7 +10,6 @@ from django.test.utils import override_settings
 from django.utils.translation import get_language, trans_real
 from modeltranslation import settings as mt_settings, translator
 
-
 from wagtail_modeltranslation.tests.test_settings import TEST_SETTINGS
 
 models = translation = None
@@ -194,7 +193,7 @@ class WagtailModeltranslationTest(WagtailModeltranslationTestBase):
         self.assertListEqual(['body_de', 'body_en'], fields)
 
         # Fetch one of the streamfield panels to see if the block was correctly created
-        child_block = models.StreamFieldPanelPage.body_en.field.stream_block.child_blocks.items()
+        child_block = list(models.StreamFieldPanelPage.body_en.field.stream_block.child_blocks.items())
 
         self.assertEquals(len(child_block), 1)
 
@@ -267,7 +266,12 @@ class WagtailModeltranslationTest(WagtailModeltranslationTestBase):
         page_base_fields = ['slug_de', 'slug_en', 'seo_title_de', 'seo_title_en', 'search_description_de',
                             'search_description_en', u'show_in_menus', u'go_live_at', u'expire_at']
 
-        self.assertItemsEqual(page_base_fields, form.base_fields.keys())
+        try:
+            # python 3
+            self.assertCountEqual(page_base_fields, form.base_fields.keys())
+        except AttributeError:
+            # python 2.7
+            self.assertItemsEqual(page_base_fields, form.base_fields.keys())
 
         inline_model_fields = ['field_name_de', 'field_name_en', 'image_chooser_de', 'image_chooser_en',
                                'fieldrow_name_de', 'fieldrow_name_en', 'name_de', 'name_en', 'image_de', 'image_en',
@@ -275,7 +279,12 @@ class WagtailModeltranslationTest(WagtailModeltranslationTestBase):
 
         related_formset_form = form.formsets['related_page_model'].form
 
-        self.assertItemsEqual(inline_model_fields, related_formset_form.base_fields.keys())
+        try:
+            # python 3
+            self.assertCountEqual(inline_model_fields, related_formset_form.base_fields.keys())
+        except AttributeError:
+            # python 2.7
+            self.assertItemsEqual(inline_model_fields, related_formset_form.base_fields.keys())
 
     def test_snippet_form(self):
         """
@@ -293,7 +302,12 @@ class WagtailModeltranslationTest(WagtailModeltranslationTestBase):
 
         related_formset_form = form.formsets['related_snippet_model'].form
 
-        self.assertItemsEqual(inline_model_fields, related_formset_form.base_fields.keys())
+        try:
+            # python 3
+            self.assertCountEqual(inline_model_fields, related_formset_form.base_fields.keys())
+        except AttributeError:
+            # python 2.7
+            self.assertItemsEqual(inline_model_fields, related_formset_form.base_fields.keys())
 
     def test_duplicate_slug(self):
         from wagtail.wagtailcore.models import Site
@@ -328,4 +342,9 @@ class WagtailModeltranslationTest(WagtailModeltranslationTestBase):
 
         model_search_fields = [searchfield.field_name for searchfield in models.PatchTestPage.search_fields]
 
-        self.assertItemsEqual(expected_fields, model_search_fields)
+        try:
+            # python 3
+            self.assertCountEqual(expected_fields, model_search_fields)
+        except AttributeError:
+            # python 2.7
+            self.assertItemsEqual(expected_fields, model_search_fields)

wagtail_modeltranslation/utils.py

@@ -2,10 +2,10 @@
 import inspect
 
 
-def compare_class_tree_depth(a, b):
+def compare_class_tree_depth(model_class):
     """
      Function to sort a list of class objects, where subclasses
     have lower indices than their superclasses
     """
 
-    return len(inspect.getmro(b)) - len(inspect.getmro(a))
+    return -len(inspect.getmro(model_class))

wagtail_modeltranslation/wagtail_hooks.py

@@ -2,12 +2,12 @@
 
 import json
 
-from django.utils.html import format_html, format_html_join
 from django.conf import settings
 from django.conf.urls import url
-from django.http import QueryDict
 from django.http import HttpResponse
-
+from django.http import QueryDict
+from django.utils.html import format_html, format_html_join
+from six import iteritems
 from wagtail.wagtailcore import hooks
 from wagtail.wagtailcore.models import Page
 
@@ -52,7 +52,7 @@ def return_translation_target_field_rendered_html(request, page_id):
         target_field_patched = []
         for item in origin_field_serialized:
             patched_item = None
-            for att in item.iteritems():
+            for att in iteritems(item):
                 target_value = att[1]
                 if att[0] == 'name':
                     target_value = att[1].replace(