Ensure absolute_import, unicode_literals imported in all files

Drone will now check that

    from __future__ absolute_import, unicode_literals

is part of every Python source file, to ensure a consistent experience
across all versions of Python.

See #2392 for an instance where missing `unicode_literals` was causing
problems.

Add missing absolute_import, unicode_literals to all files

Explicitly ensure strings are of the correct types

Now that unicode_literals is in every file, some things that used to
be py2 `str`s were now `unicode` instead. This caused issues with
generated class / function names, which must be `str` in all versions of
Python. This means bytes in py2, and unicode in py3. A test also checked
for the incorrect type of SafeString. HTML content should always be
unicode, so this has been fixed.

setup.cfg

@@ -4,3 +4,5 @@ universal = 1
 [isort]
 line_length=100
 multi_line_output=4
+skip=migrations
+add_imports=from __future__ import absolute_import,from __future__ import unicode_literals

wagtail/api/apps.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.apps import AppConfig, apps
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured

wagtail/api/v2/endpoints.py

@@ -1,4 +1,4 @@
-from __future__ import absolute_import
+from __future__ import absolute_import, unicode_literals
 
 from collections import OrderedDict
 

wagtail/api/v2/filters.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.conf import settings
 from rest_framework.filters import BaseFilterBackend
 from taggit.managers import _TaggableManager

wagtail/api/v2/pagination.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from collections import OrderedDict
 
 from django.conf import settings

wagtail/api/v2/router.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 import functools
 
 from django.conf.urls import include, url

wagtail/api/v2/serializers.py

@@ -1,4 +1,4 @@
-from __future__ import absolute_import
+from __future__ import absolute_import, unicode_literals
 
 from collections import OrderedDict
 
@@ -393,7 +393,7 @@ def get_serializer_class(model_, fields_, meta_fields=None, base=BaseSerializer)
         model = model_
         fields = base.default_fields + list(fields_)
 
-    return type(model_.__name__ + 'Serializer', (base, ), {
+    return type(str(model_.__name__ + 'Serializer'), (base, ), {
         'Meta': Meta,
         'meta_fields': base.meta_fields + list(meta_fields or []),
     })

wagtail/api/v2/signal_handlers.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.core.urlresolvers import reverse
 from django.db.models.signals import post_delete, post_save
 

wagtail/api/v2/tests/test_documents.py

@@ -1,4 +1,4 @@
-from __future__ import unicode_literals
+from __future__ import absolute_import, unicode_literals
 
 import json
 

wagtail/api/v2/tests/test_images.py

@@ -1,4 +1,4 @@
-from __future__ import unicode_literals
+from __future__ import absolute_import, unicode_literals
 
 import json
 

wagtail/api/v2/tests/test_pages.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 import collections
 import json
 

wagtail/api/v2/urls.py

@@ -1,4 +1,4 @@
-from __future__ import absolute_import
+from __future__ import absolute_import, unicode_literals
 
 from django.conf.urls import url
 

wagtail/api/v2/utils.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.conf import settings
 from django.utils.six.moves.urllib.parse import urlparse
 

wagtail/bin/wagtail.py

@@ -1,5 +1,5 @@
 #!/usr/bin/env python
-from __future__ import absolute_import, print_function
+from __future__ import absolute_import, print_function, unicode_literals
 
 import os
 from optparse import OptionParser

wagtail/contrib/settings/apps.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.apps import AppConfig
 
 

wagtail/contrib/settings/context_processors.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.utils.encoding import python_2_unicode_compatible
 
 from .registry import registry

wagtail/contrib/settings/models.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.db import models
 
 from .registry import register_setting

wagtail/contrib/settings/permissions.py

@@ -1,3 +1,6 @@
+from __future__ import absolute_import, unicode_literals
+
+
 def user_can_edit_setting_type(user, model):
     """ Check if a user has permission to edit this setting type """
     return user.has_perm("{}.change_{}".format(

wagtail/contrib/settings/registry.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.apps import apps
 from django.contrib.auth.models import Permission
 from django.core.urlresolvers import reverse

wagtail/contrib/settings/templatetags/wagtailsettings_tags.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.template import Library
 
 from wagtail.wagtailcore.models import Site

wagtail/contrib/settings/tests/test_register.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.core.urlresolvers import reverse
 from django.test import TestCase
 

wagtail/contrib/settings/tests/test_templates.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.template import Context, RequestContext, Template
 from django.test import TestCase
 

wagtail/contrib/settings/urls.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.conf.urls import url
 
 from . import views

wagtail/contrib/settings/views.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.core.exceptions import PermissionDenied
 from django.http import Http404
 from django.shortcuts import get_object_or_404, redirect, render

wagtail/contrib/settings/wagtail_hooks.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.conf.urls import include, url
 
 from wagtail.wagtailcore import hooks

wagtail/contrib/wagtailapi/apps.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.apps import AppConfig, apps
 from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured

wagtail/contrib/wagtailapi/endpoints.py

@@ -1,4 +1,4 @@
-from __future__ import absolute_import
+from __future__ import absolute_import, unicode_literals
 
 from collections import OrderedDict
 

wagtail/contrib/wagtailapi/filters.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.conf import settings
 from rest_framework.filters import BaseFilterBackend
 from taggit.managers import _TaggableManager

wagtail/contrib/wagtailapi/pagination.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from collections import OrderedDict
 
 from django.conf import settings

wagtail/contrib/wagtailapi/router.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 import functools
 
 from django.conf.urls import include, url

wagtail/contrib/wagtailapi/serializers.py

@@ -1,4 +1,4 @@
-from __future__ import absolute_import
+from __future__ import absolute_import, unicode_literals
 
 from collections import OrderedDict
 
@@ -284,6 +284,6 @@ def get_serializer_class(model_, fields_, base=BaseSerializer):
         model = model_
         fields = fields_
 
-    return type(model_.__name__ + 'Serializer', (base, ), {
+    return type(str(model_.__name__ + 'Serializer'), (base, ), {
         'Meta': Meta
     })

wagtail/contrib/wagtailapi/signal_handlers.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.core.urlresolvers import reverse
 from django.db.models.signals import post_delete, post_save
 

wagtail/contrib/wagtailapi/tests/test_documents.py

@@ -1,4 +1,4 @@
-from __future__ import unicode_literals
+from __future__ import absolute_import, unicode_literals
 
 import json
 

wagtail/contrib/wagtailapi/tests/test_images.py

@@ -1,4 +1,4 @@
-from __future__ import unicode_literals
+from __future__ import absolute_import, unicode_literals
 
 import json
 

wagtail/contrib/wagtailapi/tests/test_pages.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 import collections
 import json
 

wagtail/contrib/wagtailapi/urls.py

@@ -1,4 +1,4 @@
-from __future__ import absolute_import
+from __future__ import absolute_import, unicode_literals
 
 from django.conf.urls import url
 

wagtail/contrib/wagtailapi/utils.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.conf import settings
 from django.utils.six.moves.urllib.parse import urlparse
 

wagtail/contrib/wagtailfrontendcache/apps.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.apps import AppConfig
 
 from wagtail.contrib.wagtailfrontendcache.signal_handlers import register_signal_handlers

wagtail/contrib/wagtailfrontendcache/backends.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 import json
 import logging
 

wagtail/contrib/wagtailfrontendcache/signal_handlers.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.apps import apps
 
 from wagtail.contrib.wagtailfrontendcache.utils import purge_page_from_cache

wagtail/contrib/wagtailfrontendcache/tests.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.test import TestCase
 from django.test.utils import override_settings
 

wagtail/contrib/wagtailfrontendcache/utils.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 import logging
 
 from django.conf import settings

wagtail/contrib/wagtailmedusa/apps.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.apps import AppConfig
 
 

wagtail/contrib/wagtailmedusa/renderers.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django_medusa.renderers import StaticSiteRenderer
 from wagtail.wagtailcore.models import Site
 from wagtail.wagtaildocs.models import Document

wagtail/contrib/wagtailroutablepage/apps.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.apps import AppConfig
 
 

wagtail/contrib/wagtailroutablepage/models.py

@@ -1,4 +1,4 @@
-from __future__ import unicode_literals
+from __future__ import absolute_import, unicode_literals
 
 from django.conf.urls import url
 from django.core.urlresolvers import RegexURLResolver

wagtail/contrib/wagtailroutablepage/templatetags/wagtailroutablepage_tags.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django import template
 
 register = template.Library()

wagtail/contrib/wagtailroutablepage/tests.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.core.urlresolvers import NoReverseMatch
 from django.test import RequestFactory, TestCase
 

wagtail/contrib/wagtailsearchpromotions/admin_urls.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.conf.urls import url
 
 from wagtail.contrib.wagtailsearchpromotions import views

wagtail/contrib/wagtailsearchpromotions/apps.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.apps import AppConfig
 
 

wagtail/contrib/wagtailsearchpromotions/forms.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django import forms
 from django.forms.models import inlineformset_factory
 from django.utils.translation import ugettext_lazy as _

wagtail/contrib/wagtailsearchpromotions/models.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.db import models
 from django.utils.translation import ugettext_lazy as _
 

wagtail/contrib/wagtailsearchpromotions/templatetags/wagtailsearchpromotions_tags.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django import template
 
 from wagtail.contrib.wagtailsearchpromotions.models import SearchPromotion

wagtail/contrib/wagtailsearchpromotions/tests.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.core.urlresolvers import reverse
 from django.test import TestCase
 

wagtail/contrib/wagtailsearchpromotions/views.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.core.urlresolvers import reverse
 from django.shortcuts import get_object_or_404, redirect, render
 from django.utils.translation import ugettext as _

wagtail/contrib/wagtailsearchpromotions/wagtail_hooks.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.conf.urls import include, url
 from django.contrib.auth.models import Permission
 from django.core import urlresolvers

wagtail/contrib/wagtailsitemaps/apps.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.apps import AppConfig
 
 

wagtail/contrib/wagtailsitemaps/sitemap_generator.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.template.loader import render_to_string
 
 

wagtail/contrib/wagtailsitemaps/tests.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.core.cache import cache
 from django.test import TestCase
 

wagtail/contrib/wagtailsitemaps/views.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.conf import settings
 from django.core.cache import cache
 from django.http import HttpResponse

wagtail/contrib/wagtailstyleguide/apps.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.apps import AppConfig
 
 

wagtail/contrib/wagtailstyleguide/tests.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.core.urlresolvers import reverse
 from django.test import TestCase
 

wagtail/contrib/wagtailstyleguide/views.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django import forms
 from django.core.paginator import Paginator
 from django.shortcuts import render

wagtail/contrib/wagtailstyleguide/wagtail_hooks.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.conf.urls import url
 from django.core import urlresolvers
 from django.utils.translation import ugettext_lazy as _

wagtail/project_template/home/models.py

@@ -1,4 +1,4 @@
-from __future__ import unicode_literals
+from __future__ import absolute_import, unicode_literals
 
 from django.db import models
 

wagtail/project_template/manage.py

@@ -1,4 +1,6 @@
 #!/usr/bin/env python
+from __future__ import absolute_import, unicode_literals
+
 import os
 import sys
 

wagtail/project_template/project_name/settings/base.py

@@ -10,6 +10,8 @@ For the full list of settings and their values, see
 https://docs.djangoproject.com/en/{{ docs_version }}/ref/settings/
 """
 
+from __future__ import absolute_import, unicode_literals
+
 # Build paths inside the project like this: os.path.join(BASE_DIR, ...)
 import os
 

wagtail/project_template/project_name/settings/dev.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from .base import *
 
 # SECURITY WARNING: don't run with debug turned on in production!

wagtail/project_template/project_name/settings/production.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from .base import *
 
 DEBUG = False

wagtail/project_template/project_name/urls.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.conf import settings
 from django.conf.urls import include, url
 from django.contrib import admin

wagtail/project_template/project_name/wsgi.py

@@ -7,6 +7,8 @@ For more information on this file, see
 https://docs.djangoproject.com/en/{{ docs_version }}/howto/deployment/wsgi/
 """
 
+from __future__ import absolute_import, unicode_literals
+
 import os
 
 from django.core.wsgi import get_wsgi_application

wagtail/project_template/search/views.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.core.paginator import EmptyPage, PageNotAnInteger, Paginator
 from django.shortcuts import render
 

wagtail/tests/context_processors.py

@@ -1,3 +1,6 @@
+from __future__ import absolute_import, unicode_literals
+
+
 def do_not_use_static_url(request):
     def exception():
         raise Exception("Do not use STATIC_URL in templates. Use the {% static %} templatetag instead.")

wagtail/tests/customuser/models.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 import sys
 
 from django.contrib.auth.models import (

wagtail/tests/demosite/models.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from datetime import date
 
 from django.db import models

wagtail/tests/dummy_external_storage.py

@@ -5,6 +5,8 @@
 #  - Calling .path on the storage or image file raises NotImplementedError
 #  - File.open() after the file has been closed raises an error
 
+from __future__ import absolute_import, unicode_literals
+
 from django.core.files.base import File
 from django.core.files.storage import FileSystemStorage, Storage
 from django.utils.deconstruct import deconstructible

wagtail/tests/non_root_urls.py

@@ -1,6 +1,8 @@
 """An alternative urlconf module where Wagtail front-end URLs
 are rooted at '/site/' rather than '/'"""
 
+from __future__ import absolute_import, unicode_literals
+
 from django.conf.urls import include, url
 
 from wagtail.wagtailadmin import urls as wagtailadmin_urls

wagtail/tests/routablepage/apps.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.apps import AppConfig
 
 

wagtail/tests/routablepage/models.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.http import HttpResponse
 
 from wagtail.contrib.wagtailroutablepage.models import RoutablePage, route

wagtail/tests/search/apps.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.apps import AppConfig
 
 

wagtail/tests/search/models.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.db import models
 from taggit.managers import TaggableManager
 

wagtail/tests/settings.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 import os
 
 WAGTAIL_ROOT = os.path.dirname(__file__)

wagtail/tests/snippets/apps.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.apps import AppConfig
 
 

wagtail/tests/snippets/forms.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from wagtail.wagtailadmin.forms import WagtailAdminModelForm
 
 

wagtail/tests/snippets/models.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.db import models
 from django.utils.encoding import python_2_unicode_compatible
 

wagtail/tests/test_utils.py

@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*
-from __future__ import unicode_literals
+from __future__ import absolute_import, unicode_literals
 
 import warnings
 

wagtail/tests/testapp/apps.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.apps import AppConfig
 
 

wagtail/tests/testapp/blocks.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from wagtail.wagtailcore import blocks
 
 

wagtail/tests/testapp/forms.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django import forms
 
 from wagtail.wagtailadmin.forms import WagtailAdminPageForm

wagtail/tests/testapp/models.py

@@ -1,4 +1,4 @@
-from __future__ import unicode_literals
+from __future__ import absolute_import, unicode_literals
 
 import hashlib
 import os

wagtail/tests/testapp/urls.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.conf.urls import url
 
 from wagtail.tests.testapp.views import bob_only_zone

wagtail/tests/testapp/views.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.http import HttpResponse
 
 from wagtail.wagtailadmin.utils import user_passes_test

wagtail/tests/testapp/wagtail_hooks.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.http import HttpResponse
 
 from wagtail.wagtailadmin.menu import MenuItem

wagtail/tests/urls.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.conf.urls import include, url
 
 from wagtail.api.v2 import urls as wagtailapi2_urls

wagtail/utils/apps.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from importlib import import_module
 
 from django.apps import apps

wagtail/utils/compat.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 import warnings
 
 from django.template import loader

wagtail/utils/deprecation.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 import warnings
 
 

wagtail/utils/pagination.py

@@ -1,3 +1,5 @@
+from __future__ import absolute_import, unicode_literals
+
 from django.core.paginator import EmptyPage, PageNotAnInteger, Paginator
 
 DEFAULT_PAGE_KEY = 'p'

wagtail/utils/sendfile.py

@@ -1,6 +1,8 @@
 # Copied from django-sendfile 0.3.6 and tweaked to allow a backend to be passed
 # to sendfile()
 # See: https://github.com/johnsensible/django-sendfile/pull/33
+from __future__ import absolute_import, unicode_literals
+
 import os.path
 from mimetypes import guess_type
 

wagtail/utils/sendfile_streaming_backend.py

@@ -1,6 +1,8 @@
 # Sendfile "streaming" backend
 # This is based on sendfiles builtin "simple" backend but uses a StreamingHttpResponse
 
+from __future__ import absolute_import, unicode_literals
+
 import os
 import re
 import stat