============================================ Django 2.0 release notes - UNDER DEVELOPMENT ============================================ Welcome to Django 2.0! These release notes cover the :ref:`new features `, as well as some :ref:`backwards incompatible changes ` you'll want to be aware of when upgrading from Django 1.11 or earlier. We've :ref:`dropped some features` that have reached the end of their deprecation cycle, and we've :ref:`begun the deprecation process for some features `. See the :doc:`/howto/upgrade-version` guide if you're updating an existing project. Python compatibility ==================== Django 2.0 supports Python 3.5+. Since Django 1.11, support for Python 2.7 and 3.4 is removed. We **highly recommend** and only officially support the latest release of each series. Third-party library support for older version of Django ======================================================= Following the release of Django 2.0, we suggest that third-party app authors drop support for all versions of Django prior to 1.11. At that time, you should be able run your package's tests using ``python -Wd`` so that deprecation warnings do appear. After making the deprecation warning fixes, your app should be compatible with Django 2.0. .. _whats-new-2.0: What's new in Django 2.0 ======================== Minor features -------------- :mod:`django.contrib.admin` ~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.admindocs` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.auth` ~~~~~~~~~~~~~~~~~~~~~~~~~~ * The default iteration count for the PBKDF2 password hasher is increased from 36,000 to 100,000. :mod:`django.contrib.contenttypes` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.gis` ~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.messages` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.postgres` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * The new ``distinct`` argument for :class:`~django.contrib.postgres.aggregates.ArrayAgg` determines if concatenated values will be distinct. :mod:`django.contrib.redirects` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.sessions` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.sitemaps` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.sites` ~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.staticfiles` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... :mod:`django.contrib.syndication` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * ... Cache ~~~~~ * ... CSRF ~~~~ * ... Database backends ~~~~~~~~~~~~~~~~~ * ... Email ~~~~~ * ... File Storage ~~~~~~~~~~~~ * ... File Uploads ~~~~~~~~~~~~ * ... Forms ~~~~~ * ... Generic Views ~~~~~~~~~~~~~ * ... Internationalization ~~~~~~~~~~~~~~~~~~~~ * ... Management Commands ~~~~~~~~~~~~~~~~~~~ * ... Migrations ~~~~~~~~~~ * ... Models ~~~~~~ * ... Requests and Responses ~~~~~~~~~~~~~~~~~~~~~~ * ... Serialization ~~~~~~~~~~~~~ * ... Signals ~~~~~~~ * ... Templates ~~~~~~~~~ * ... Tests ~~~~~ * ... URLs ~~~~ * ... Validators ~~~~~~~~~~ * ... .. _backwards-incompatible-2.0: Backwards incompatible changes in 2.0 ===================================== Removed support for bytestrings in some places ---------------------------------------------- To support native Python 2 strings, older Django versions had to accept both bytestrings and unicode strings. Now that Python 2 support is dropped, bytestrings should only be encountered around input/output boundaries (handling of binary fields or HTTP streams, for example). You might have to update your code to limit bytestring usage to a minimum, as Django no longer accepts bytestrings in certain code paths. Database backend API -------------------- * ... Dropped support for Oracle 11.2 ------------------------------- The end of upstream support for Oracle 11.2 is Dec. 2020. Django 1.11 will be supported until April 2020 which almost reaches this date. Django 2.0 officially supports Oracle 12.1+. Default MySQL isolation level is read committed ----------------------------------------------- MySQL's default isolation level, repeatable read, may cause data loss in typical Django usage. To prevent that and for consistency with other databases, the default isolation level is now read committed. You can use the :setting:`DATABASES` setting to :ref:`use a different isolation level `, if needed. :attr:`AbstractUser.last_name ` ``max_length`` increased to 150 ---------------------------------------------------------------------------------------------------------- A migration for :attr:`django.contrib.auth.models.User.last_name` is included. If you have a custom user model inheriting from ``AbstractUser``, you'll need to generate and apply a database migration for your user model. If you want to preserve the 30 character limit for last names, use a custom form:: from django.contrib.auth.forms import UserChangeForm class MyUserChangeForm(UserChangeForm): last_name = forms.CharField(max_length=30, required=False) If you wish to keep this restriction in the admin when editing users, set ``UserAdmin.form`` to use this form:: from django.contrib.auth.admin import UserAdmin from django.contrib.auth.models import User class MyUserAdmin(UserAdmin): form = MyUserChangeForm admin.site.unregister(User) admin.site.register(User, MyUserAdmin) Miscellaneous ------------- * The ``SessionAuthenticationMiddleware`` class is removed. It provided no functionality since session authentication is unconditionally enabled in Django 1.10. * The default HTTP error handlers (``handler404``, etc.) are now callables instead of dotted Python path strings. Django favors callable references since they provide better performance and debugging experience. .. _deprecated-features-2.0: Features deprecated in 2.0 ========================== Miscellaneous ------------- * The ``django.db.backends.postgresql_psycopg2`` module is deprecated in favor of ``django.db.backends.postgresql``. It's been an alias since Django 1.9. This only affects code that imports from the module directly. The ``DATABASES`` setting can still use ``'django.db.backends.postgresql_psycopg2'``, though you can simplify that by using the ``'django.db.backends.postgresql'`` name added in Django 1.9. .. _removed-features-2.0: Features removed in 2.0 ======================= These features have reached the end of their deprecation cycle and are removed in Django 2.0. See :ref:`deprecated-features-1.9` and :ref:`deprecated-features-1.10` for details, including how to remove usage of these features. * The ``weak`` argument to ``django.dispatch.signals.Signal.disconnect()`` is removed. * ``django.db.backends.base.BaseDatabaseOperations.check_aggregate_support()`` is removed. * The ``django.forms.extras`` package is removed. * The ``assignment_tag`` helper is removed. * The ``host`` argument to ``SimpleTestCase.assertsRedirects()`` is removed. The compatibility layer which allows absolute URLs to be considered equal to relative ones when the path is identical is also removed. * ``Field.rel`` and ``Field.remote_field.to`` are removed. * The ``on_delete`` argument for ``ForeignKey`` and ``OneToOneField`` are now required. * ``django.db.models.fields.add_lazy_relation()`` is removed. * When time zone support is enabled, database backends that don't support time zones no longer convert aware datetimes to naive values in UTC anymore when such values are passed as parameters to SQL queries executed outside of the ORM, e.g. with ``cursor.execute()``. * ``django.contrib.auth.tests.utils.skipIfCustomUser()`` is removed. * The ``GeoManager`` and ``GeoQuerySet`` classes are removed. * The ``django.contrib.gis.geoip`` module is removed. * The ``supports_recursion`` check for template loaders is removed from: * ``django.template.engine.Engine.find_template()`` * ``django.template.loader_tags.ExtendsNode.find_template()`` * ``django.template.loaders.base.Loader.supports_recursion()`` * ``django.template.loaders.cached.Loader.supports_recursion()`` * The ``load_template`` and ``load_template_sources`` template loader methods are removed. * The ``template_dirs`` argument for template loaders is removed: * ``django.template.loaders.base.Loader.get_template()`` * ``django.template.loaders.cached.Loader.cache_key()`` * ``django.template.loaders.cached.Loader.get_template()`` * ``django.template.loaders.cached.Loader.get_template_sources()`` * ``django.template.loaders.filesystem.Loader.get_template_sources()`` * ``django.template.loaders.base.Loader.__call__()`` is removed. * Support for custom error views that don't accept an ``exception`` parameter is removed. * The ``mime_type`` attribute of ``django.utils.feedgenerator.Atom1Feed`` and ``django.utils.feedgenerator.RssFeed`` is removed. * The ``app_name`` argument to ``include()`` is removed. * Support for passing a 3-tuple as the first argument to ``include()`` is removed. * Support for setting a URL instance namespace without an application namespace is removed. * ``Field._get_val_from_obj()`` is removed. * ``django.template.loaders.eggs.Loader`` is removed. * The ``current_app`` parameter to the ``contrib.auth`` function-based views is removed. * The ``callable_obj`` keyword argument to ``SimpleTestCase.assertRaisesMessage()`` is removed. * Support for the ``allow_tags`` attribute on ``ModelAdmin`` methods is removed. * The ``enclosure`` keyword argument to ``SyndicationFeed.add_item()`` is removed. * The ``django.template.loader.LoaderOrigin`` and ``django.template.base.StringOrigin`` aliases for ``django.template.base.Origin`` are removed. * The ``makemigrations --exit`` option is removed. * Support for direct assignment to a reverse foreign key or many-to-many relation is removed. * The ``get_srid()`` and ``set_srid()`` methods of ``django.contrib.gis.geos.GEOSGeometry`` are removed. * The ``get_x()``, ``set_x()``, ``get_y()``, ``set_y()``, ``get_z()``, and ``set_z()`` methods of ``django.contrib.gis.geos.Point`` are removed. * The ``get_coords()`` and ``set_coords()`` methods of ``django.contrib.gis.geos.Point`` are removed. * The ``cascaded_union`` property of ``django.contrib.gis.geos.MultiPolygon`` is removed. * ``django.utils.functional.allow_lazy()`` is removed. * The ``shell --plain`` option is removed. * The ``django.core.urlresolvers`` module is removed. * ``CommaSeparatedIntegerField`` is removed, except for support in historical migrations. * The template ``Context.has_key()`` method is removed. * Support for the ``django.core.files.storage.Storage.accessed_time()``, ``created_time()``, and ``modified_time()`` methods is removed. * Support for query lookups using the model name when ``Meta.default_related_name`` is set is removed. * The MySQL ``__search`` lookup is removed. * The shim for supporting custom related manager classes without a ``_apply_rel_filters()`` method is removed. * Using ``User.is_authenticated()`` and ``User.is_anonymous()`` as methods rather than properties is no longer supported. * The ``Model._meta.virtual_fields`` attribute is removed. * The keyword arguments ``virtual_only`` in ``Field.contribute_to_class()`` and ``virtual`` in ``Model._meta.add_field()`` are removed. * The ``javascript_catalog()`` and ``json_catalog()`` views are removed. * ``django.contrib.gis.utils.precision_wkt()`` is removed. * In multi-table inheritance, implicit promotion of a ``OneToOneField`` to a ``parent_link`` is removed. * Support for ``Widget._format_value()`` is removed. * ``FileField`` methods ``get_directory_name()`` and ``get_filename()`` are removed. * The ``mark_for_escaping()`` function and the classes it uses: ``EscapeData``, ``EscapeBytes``, ``EscapeText``, ``EscapeString``, and ``EscapeUnicode`` are removed. * The ``escape`` filter now uses ``django.utils.html.conditional_escape()``. * ``Manager.use_for_related_fields`` is removed. * Model ``Manager`` inheritance follows MRO inheritance rules. The requirement to use ``Meta.manager_inheritance_from_future`` to opt-in to the behavior is removed. * Support for old-style middleware using ``settings.MIDDLEWARE_CLASSES`` is removed.