fixes to Django 3.0

categories/base.py

@@ -6,7 +6,7 @@
 from django.contrib import admin
 from django.db import models
 from django import forms
-from django.utils.encoding import force_text, python_2_unicode_compatible
+from django.utils.encoding import force_text
 from django.utils.translation import ugettext_lazy as _
 
 from mptt.models import MPTTModel
@@ -29,7 +29,6 @@ def active(self):
         return self.get_queryset().filter(active=True)
 
 
-@python_2_unicode_compatible
 class CategoryBase(MPTTModel):
     """
     This base model includes the absolute bare bones fields and methods. One

categories/editor/tree_editor.py

@@ -4,7 +4,7 @@
 from django.http import HttpResponseRedirect
 from django.utils.translation import ugettext_lazy as _
 from django.contrib.admin.options import IncorrectLookupParameters
-from django.shortcuts import render_to_response
+from django.shortcuts import render
 
 import django
 
@@ -170,7 +170,7 @@ def old_changelist_view(self, request, extra_context=None):
             # the 'invalid=1' parameter was already in the query string, something
             # is screwed up with the database, so display an error page.
             if ERROR_FLAG in list(request.GET.keys()):
-                return render_to_response(
+                return render(request,
                     'admin/invalid_setup.html', {'title': _('Database error')})
             return HttpResponseRedirect(request.path + '?' + ERROR_FLAG + '=1')
 
@@ -262,7 +262,7 @@ def old_changelist_view(self, request, extra_context=None):
             context['opts'] = self.model._meta
 
         context.update(extra_context or {})
-        return render_to_response(self.change_list_template or [
+        return render(request, self.change_list_template or [
             'admin/%s/%s/change_list.html' % (app_label, opts.object_name.lower()),
             'admin/%s/change_list.html' % app_label,
             'admin/change_list.html'

categories/templatetags/category_tags.py

@@ -2,7 +2,7 @@
 from django.apps import apps
 from django.template import (Node, TemplateSyntaxError, VariableDoesNotExist)
 from django.template.base import FilterExpression
-from django.utils.six import string_types
+from six import string_types
 from categories.base import CategoryBase
 from categories.models import Category
 from mptt.utils import drilldown_tree_for_node