django/docs/releases/5.0.txt

========================
Django 5.0 release notes
========================

*December 4, 2023*

Welcome to Django 5.0!

These release notes cover the :ref:`new features <whats-new-5.0>`, as well as
some :ref:`backwards incompatible changes <backwards-incompatible-5.0>` you'll
want to be aware of when upgrading from Django 4.2 or earlier. We've
:ref:`begun the deprecation process for some features
<deprecated-features-5.0>`.

See the :doc:`/howto/upgrade-version` guide if you're updating an existing
project.

Python compatibility
====================

Django 5.0 supports Python 3.10, 3.11, and 3.12. We **highly recommend** and
only officially support the latest release of each series.

The Django 4.2.x series is the last to support Python 3.8 and 3.9.

Third-party library support for older version of Django
=======================================================

Following the release of Django 5.0, we suggest that third-party app authors
drop support for all versions of Django prior to 4.2. At that time, you should
be able to run your package's tests using ``python -Wd`` so that deprecation
warnings appear. After making the deprecation warning fixes, your app should be
compatible with Django 5.0.

.. _whats-new-5.0:

What's new in Django 5.0
========================

Facet filters in the admin
--------------------------

Facet counts are now shown for applied filters in the admin changelist when
toggled on via the UI. This behavior can be changed via the new
:attr:`.ModelAdmin.show_facets` attribute. For more information see
:ref:`facet-filters`.

Simplified templates for form field rendering
---------------------------------------------

Django 5.0 introduces the concept of a field group, and field group templates.
This simplifies rendering of the related elements of a Django form field such
as its label, widget, help text, and errors.

For example, the template below:

.. code-block:: html+django

    <form>
    ...
    <div>
      {{ form.name.label_tag }}
      {% if form.name.help_text %}
        <div class="helptext" id="{{ form.name.auto_id }}_helptext">
          {{ form.name.help_text|safe }}
        </div>
      {% endif %}
      {{ form.name.errors }}
      {{ form.name }}
      <div class="row">
        <div class="col">
          {{ form.email.label_tag }}
          {% if form.email.help_text %}
            <div class="helptext" id="{{ form.email.auto_id }}_helptext">
              {{ form.email.help_text|safe }}
            </div>
          {% endif %}
          {{ form.email.errors }}
          {{ form.email }}
        </div>
        <div class="col">
          {{ form.password.label_tag }}
          {% if form.password.help_text %}
            <div class="helptext" id="{{ form.password.auto_id }}_helptext">
              {{ form.password.help_text|safe }}
            </div>
          {% endif %}
          {{ form.password.errors }}
          {{ form.password }}
        </div>
      </div>
    </div>
    ...
    </form>

Can now be simplified to:

.. code-block:: html+django

    <form>
    ...
    <div>
      {{ form.name.as_field_group }}
      <div class="row">
        <div class="col">{{ form.email.as_field_group }}</div>
        <div class="col">{{ form.password.as_field_group }}</div>
      </div>
    </div>
    ...
    </form>

:meth:`~django.forms.BoundField.as_field_group` renders fields with the
``"django/forms/field.html"`` template by default and can be customized on a
per-project, per-field, or per-request basis. See
:ref:`reusable-field-group-templates`.

Database-computed default values
--------------------------------

The new :attr:`Field.db_default <django.db.models.Field.db_default>` parameter
sets a database-computed default value. For example::

    from django.db import models
    from django.db.models.functions import Now, Pi


    class MyModel(models.Model):
        age = models.IntegerField(db_default=18)
        created = models.DateTimeField(db_default=Now())
        circumference = models.FloatField(db_default=2 * Pi())

Database generated model field
------------------------------

The new :class:`~django.db.models.GeneratedField` allows creation of database
generated columns. This field can be used on all supported database backends
to create a field that is always computed from other fields. For example::

    from django.db import models
    from django.db.models import F


    class Square(models.Model):
        side = models.IntegerField()
        area = models.GeneratedField(
            expression=F("side") * F("side"),
            output_field=models.BigIntegerField(),
            db_persist=True,
        )

More options for declaring field choices
----------------------------------------

:attr:`.Field.choices` *(for model fields)* and :attr:`.ChoiceField.choices`
*(for form fields)* allow for more flexibility when declaring their values. In
previous versions of Django, ``choices`` should either be a list of 2-tuples,
or an :ref:`field-choices-enum-types` subclass, but the latter required
accessing the ``.choices`` attribute to provide the values in the expected
form::

    from django.db import models

    Medal = models.TextChoices("Medal", "GOLD SILVER BRONZE")

    SPORT_CHOICES = [
        ("Martial Arts", [("judo", "Judo"), ("karate", "Karate")]),
        ("Racket", [("badminton", "Badminton"), ("tennis", "Tennis")]),
        ("unknown", "Unknown"),
    ]


    class Winner(models.Model):
        name = models.CharField(...)
        medal = models.CharField(..., choices=Medal.choices)
        sport = models.CharField(..., choices=SPORT_CHOICES)

Django 5.0 adds support for accepting a mapping or a callable instead of an
iterable, and also no longer requires ``.choices`` to be used directly to
expand :ref:`enumeration types <field-choices-enum-types>`::

    from django.db import models

    Medal = models.TextChoices("Medal", "GOLD SILVER BRONZE")

    SPORT_CHOICES = {  # Using a mapping instead of a list of 2-tuples.
        "Martial Arts": {"judo": "Judo", "karate": "Karate"},
        "Racket": {"badminton": "Badminton", "tennis": "Tennis"},
        "unknown": "Unknown",
    }


    def get_scores():
        return [(i, str(i)) for i in range(10)]


    class Winner(models.Model):
        name = models.CharField(...)
        medal = models.CharField(..., choices=Medal)  # Using `.choices` not required.
        sport = models.CharField(..., choices=SPORT_CHOICES)
        score = models.IntegerField(choices=get_scores)  # A callable is allowed.

Under the hood the provided ``choices`` are normalized into a list of 2-tuples
as the canonical form whenever the ``choices`` value is updated. For more
information, please check the :ref:`model field reference on choices
<field-choices>`.

Minor features
--------------

:mod:`django.contrib.admin`
~~~~~~~~~~~~~~~~~~~~~~~~~~~

* The new :meth:`.AdminSite.get_log_entries` method allows customizing the
  queryset for the site's listed log entries.

* The ``django.contrib.admin.AllValuesFieldListFilter``,
  ``ChoicesFieldListFilter``, ``RelatedFieldListFilter``, and
  ``RelatedOnlyFieldListFilter`` admin filters now handle multi-valued query
  parameters.

* ``XRegExp`` is upgraded from version 3.2.0 to 5.1.1.

* The new :meth:`.AdminSite.get_model_admin` method returns an admin class for
  the given model class.

* Properties in :attr:`.ModelAdmin.list_display` now support ``boolean``
  attribute.

* jQuery is upgraded from version 3.6.4 to 3.7.1.


:mod:`django.contrib.auth`
~~~~~~~~~~~~~~~~~~~~~~~~~~

* The default iteration count for the PBKDF2 password hasher is increased from
  600,000 to 720,000.

* The new asynchronous functions are now provided, using an
  ``a`` prefix: :func:`django.contrib.auth.aauthenticate`,
  :func:`~.django.contrib.auth.aget_user`,
  :func:`~.django.contrib.auth.alogin`, :func:`~.django.contrib.auth.alogout`,
  and :func:`~.django.contrib.auth.aupdate_session_auth_hash`.

* ``AuthenticationMiddleware`` now adds an :meth:`.HttpRequest.auser`
  asynchronous method that returns the currently logged-in user.

* The new :func:`django.contrib.auth.hashers.acheck_password` asynchronous
  function and :meth:`.AbstractBaseUser.acheck_password` method allow
  asynchronous checking of user passwords.

:mod:`django.contrib.contenttypes`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* :meth:`.QuerySet.prefetch_related` now supports prefetching
  :class:`~django.contrib.contenttypes.fields.GenericForeignKey` with
  non-homogeneous set of results.

:mod:`django.contrib.gis`
~~~~~~~~~~~~~~~~~~~~~~~~~

* The new
  :class:`ClosestPoint() <django.contrib.gis.db.models.functions.ClosestPoint>`
  function returns a 2-dimensional point on the geometry that is closest to
  another geometry.

* :ref:`GIS aggregates <gis-aggregation-functions>` now support the ``filter``
  argument.

* Support for GDAL 3.7 and GEOS 3.12 is added.

* The new :meth:`.GEOSGeometry.equals_identical` method allows point-wise
  equivalence checking of geometries.

:mod:`django.contrib.messages`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* The new :meth:`.MessagesTestMixin.assertMessages` assertion method allows
  testing :mod:`~django.contrib.messages` added to a
  :class:`response <django.http.HttpResponse>`.

:mod:`django.contrib.postgres`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* The new :attr:`~.ExclusionConstraint.violation_error_code` attribute of
  :class:`~django.contrib.postgres.constraints.ExclusionConstraint` allows
  customizing the ``code`` of ``ValidationError`` raised during
  :ref:`model validation <validating-objects>`.

Asynchronous views
~~~~~~~~~~~~~~~~~~

* Under ASGI, ``http.disconnect`` events are now handled. This allows views to
  perform any necessary cleanup if a client disconnects before the response is
  generated. See :ref:`async-handling-disconnect` for more details.

Decorators
~~~~~~~~~~

* The following decorators now support wrapping asynchronous view functions:

  * :func:`~django.views.decorators.cache.cache_control`
  * :func:`~django.views.decorators.cache.never_cache`
  * :func:`~django.views.decorators.common.no_append_slash`
  * :func:`~django.views.decorators.csrf.csrf_exempt`
  * :func:`~django.views.decorators.csrf.csrf_protect`
  * :func:`~django.views.decorators.csrf.ensure_csrf_cookie`
  * :func:`~django.views.decorators.csrf.requires_csrf_token`
  * :func:`~django.views.decorators.debug.sensitive_variables`
  * :func:`~django.views.decorators.debug.sensitive_post_parameters`
  * :func:`~django.views.decorators.gzip.gzip_page`
  * :func:`~django.views.decorators.http.condition`
  * ``conditional_page()``
  * :func:`~django.views.decorators.http.etag`
  * :func:`~django.views.decorators.http.last_modified`
  * :func:`~django.views.decorators.http.require_http_methods`
  * :func:`~django.views.decorators.http.require_GET`
  * :func:`~django.views.decorators.http.require_POST`
  * :func:`~django.views.decorators.http.require_safe`
  * :func:`~django.views.decorators.vary.vary_on_cookie`
  * :func:`~django.views.decorators.vary.vary_on_headers`
  * ``xframe_options_deny()``
  * ``xframe_options_sameorigin()``
  * ``xframe_options_exempt()``

Error Reporting
~~~~~~~~~~~~~~~

* :func:`~django.views.decorators.debug.sensitive_variables` and
  :func:`~django.views.decorators.debug.sensitive_post_parameters` can now be
  used with asynchronous functions.

File Storage
~~~~~~~~~~~~

* :meth:`.File.open` now passes all positional (``*args``) and keyword
  arguments (``**kwargs``) to Python's built-in :func:`python:open`.

Forms
~~~~~

* The new :attr:`~django.forms.URLField.assume_scheme` argument for
  :class:`~django.forms.URLField` allows specifying a default URL scheme.

* In order to improve accessibility, the following changes are made:

  * Form fields now include the ``aria-describedby`` HTML attribute to enable
    screen readers to associate form fields with their help text.
  * Invalid form fields now include the ``aria-invalid="true"`` HTML attribute.

Internationalization
~~~~~~~~~~~~~~~~~~~~

* Support and translations for the Uyghur language are now available.

Migrations
~~~~~~~~~~

* Serialization of functions decorated with :func:`functools.cache` or
  :func:`functools.lru_cache` is now supported without the need to write a
  custom serializer.

Models
~~~~~~

* The new ``create_defaults`` argument of :meth:`.QuerySet.update_or_create`
  and :meth:`.QuerySet.aupdate_or_create` methods allows specifying a different
  field values for the create operation.

* The new ``violation_error_code`` attribute of
  :class:`~django.db.models.BaseConstraint`,
  :class:`~django.db.models.CheckConstraint`, and
  :class:`~django.db.models.UniqueConstraint` allows customizing the ``code``
  of ``ValidationError`` raised during
  :ref:`model validation <validating-objects>`.

* The :ref:`force_insert <ref-models-force-insert>` argument of
  :meth:`.Model.save` now allows specifying a tuple of parent classes that must
  be forced to be inserted.

* :meth:`.QuerySet.bulk_create` and :meth:`.QuerySet.abulk_create` methods now
  set the primary key on each model instance when the ``update_conflicts``
  parameter is enabled (if the database supports it).

* The new :attr:`.UniqueConstraint.nulls_distinct` attribute allows customizing
  the treatment of ``NULL`` values on PostgreSQL 15+.

* The new :func:`~django.shortcuts.aget_object_or_404` and
  :func:`~django.shortcuts.aget_list_or_404` asynchronous shortcuts allow
  asynchronous getting objects.

* The new :func:`~django.db.models.aprefetch_related_objects` function allows
  asynchronous prefetching of model instances.

* :meth:`.QuerySet.aiterator` now supports previous calls to
  ``prefetch_related()``.

* On MariaDB 10.7+, ``UUIDField`` is now created as ``UUID`` column rather than
  ``CHAR(32)`` column. See the migration guide above for more details on
  :ref:`migrating-uuidfield`.

* Django now supports `oracledb`_ version 1.3.2 or higher. Support for
  ``cx_Oracle`` is deprecated as of this release and will be removed in Django
  6.0.

Pagination
~~~~~~~~~~

* The new :attr:`django.core.paginator.Paginator.error_messages` argument
  allows customizing the error messages raised by :meth:`.Paginator.page`.

Signals
~~~~~~~

* The new :meth:`.Signal.asend` and :meth:`.Signal.asend_robust` methods allow
  asynchronous signal dispatch. Signal receivers may be synchronous or
  asynchronous, and will be automatically adapted to the correct calling style.

Templates
~~~~~~~~~

* The new :tfilter:`escapeseq` template filter applies :tfilter:`escape` to
  each element of a sequence.

Tests
~~~~~

* :class:`~django.test.Client` and :class:`~django.test.AsyncClient` now
  provide asynchronous methods, using an ``a`` prefix:
  :meth:`~django.test.Client.asession`, :meth:`~django.test.Client.alogin`,
  :meth:`~django.test.Client.aforce_login`, and
  :meth:`~django.test.Client.alogout`.

* :class:`~django.test.AsyncClient` now supports the ``follow`` parameter.

* :class:`~django.test.runner.DiscoverRunner` now allows showing the duration
  of the slowest tests using the :option:`test --durations` option (available
  on Python 3.12+).

Validators
~~~~~~~~~~

* The new ``offset`` argument of
  :class:`~django.core.validators.StepValueValidator` allows specifying an
  offset for valid values.

.. _backwards-incompatible-5.0:

Backwards incompatible changes in 5.0
=====================================

Database backend API
--------------------

This section describes changes that may be needed in third-party database
backends.

* ``DatabaseFeatures.supports_expression_defaults`` should be set to ``False``
  if the database doesn't support using database functions as defaults.

* ``DatabaseFeatures.supports_default_keyword_in_insert`` should be set to
  ``False`` if the database doesn't support the ``DEFAULT`` keyword in
  ``INSERT`` queries.

* ``DatabaseFeatures.supports_default_keyword_in_bulk_insert`` should be set to
  ``False`` if the database doesn't support the ``DEFAULT`` keyword in bulk
  ``INSERT`` queries.

:mod:`django.contrib.gis`
-------------------------

* Support for GDAL 2.2 and 2.3 is removed.

* Support for GEOS 3.6 and 3.7 is removed.

:mod:`django.contrib.sitemaps`
------------------------------

* The ``django.contrib.sitemaps.ping_google()`` function and the
  ``ping_google`` management command are removed as the Google
  Sitemaps ping endpoint is deprecated and will be removed in January 2024.

* The ``django.contrib.sitemaps.SitemapNotFound`` exception class is removed.

Dropped support for MySQL < 8.0.11
----------------------------------

Support for pre-releases of MySQL 8.0.x series is removed. Django 5.0 supports
MySQL 8.0.11 and higher.

Using ``create_defaults__exact`` may now be required with ``QuerySet.update_or_create()``
-----------------------------------------------------------------------------------------

:meth:`.QuerySet.update_or_create` now supports the parameter
``create_defaults``. As a consequence, any models that have a field named
``create_defaults`` that are used with an ``update_or_create()`` should specify
the field in the lookup with ``create_defaults__exact``.

.. _migrating-uuidfield:

Migrating existing ``UUIDField`` on MariaDB 10.7+
-------------------------------------------------

On MariaDB 10.7+, ``UUIDField`` is now created as ``UUID`` column rather than
``CHAR(32)`` column. As a consequence, any ``UUIDField`` created in
Django < 5.0 should be replaced with a ``UUIDField`` subclass backed by
``CHAR(32)``::

    class Char32UUIDField(models.UUIDField):
        def db_type(self, connection):
            return "char(32)"

        def get_db_prep_value(self, value, connection, prepared=False):
            value = super().get_db_prep_value(value, connection, prepared)
            if value is not None:
                value = value.hex
            return value

For example::

    class MyModel(models.Model):
        uuid = models.UUIDField(primary_key=True, default=uuid.uuid4)

Should become::

    class Char32UUIDField(models.UUIDField): ...


    class MyModel(models.Model):
        uuid = Char32UUIDField(primary_key=True, default=uuid.uuid4)

Running the :djadmin:`makemigrations` command will generate a migration
containing a no-op ``AlterField`` operation.

Miscellaneous
-------------

* The ``instance`` argument of the undocumented
  ``BaseModelFormSet.save_existing()`` method is renamed to ``obj``.

* The undocumented ``django.contrib.admin.helpers.checkbox`` is removed.

* Integer fields are now validated as 64-bit integers on SQLite to match the
  behavior of ``sqlite3``.

* The undocumented ``Query.annotation_select_mask`` attribute is changed from a
  set of strings to an ordered list of strings.

* ``ImageField.update_dimension_fields()`` is no longer called on the
  ``post_init`` signal if ``width_field`` and ``height_field`` are not set.

* :class:`~django.db.models.functions.Now` database function now uses
  ``LOCALTIMESTAMP`` instead of ``CURRENT_TIMESTAMP`` on Oracle.

* :attr:`.AdminSite.site_header` is now rendered in a ``<div>`` tag instead of
  ``<h1>``. Screen reader users rely on heading elements for navigation within
  a page. Having two ``<h1>`` elements was confusing and the site header wasn't
  helpful as it is repeated on all pages.

* In order to improve accessibility, the admin's main content area and header
  content area are now rendered in a ``<main>`` and ``<header>`` tag instead of
  ``<div>``.

* On databases without native support for the SQL ``XOR`` operator, ``^`` as
  the exclusive or (``XOR``) operator now returns rows that are matched by an
  odd number of operands rather than exactly one operand. This is consistent
  with the behavior of MySQL, MariaDB, and Python.

* The minimum supported version of ``asgiref`` is increased from 3.6.0 to
  3.7.0.

* The minimum supported version of ``selenium`` is increased from 3.8.0 to
  4.8.0.

* The ``AlreadyRegistered`` and ``NotRegistered`` exceptions are moved from
  ``django.contrib.admin.sites`` to ``django.contrib.admin.exceptions``.

* The minimum supported version of SQLite is increased from 3.21.0 to 3.27.0.

* Support for ``cx_Oracle`` < 8.3 is removed.

* Executing SQL queries before the app registry has been fully populated now
  raises :exc:`RuntimeWarning`.

* :exc:`~django.core.exceptions.BadRequest` is raised for non-UTF-8 encoded
  requests with the :mimetype:`application/x-www-form-urlencoded` content type.
  See :rfc:`1866` for more details.

* The minimum supported version of ``colorama`` is increased to 0.4.6.

* The minimum supported version of ``docutils`` is increased to 0.19.

* Filtering querysets against overflowing integer values now always returns an
  empty queryset. As a consequence, you may need to use ``ExpressionWrapper()``
  to :ref:`explicitly wrap <using-f-with-annotations>` arithmetic against
  integer fields in such cases.

.. _deprecated-features-5.0:

Features deprecated in 5.0
==========================

Miscellaneous
-------------

* The ``DjangoDivFormRenderer`` and ``Jinja2DivFormRenderer`` transitional form
  renderers are deprecated.

* Passing positional arguments ``name`` and ``violation_error_message`` to
  :class:`~django.db.models.BaseConstraint` is deprecated in favor of
  keyword-only arguments.

* ``request`` is added to the signature of :meth:`.ModelAdmin.lookup_allowed`.
  Support for ``ModelAdmin`` subclasses that do not accept this argument is
  deprecated.

* The ``get_joining_columns()`` method of ``ForeignObject`` and
  ``ForeignObjectRel`` is deprecated. Starting with Django 6.0,
  ``django.db.models.sql.datastructures.Join`` will no longer fallback to
  ``get_joining_columns()``. Subclasses should implement
  ``get_joining_fields()`` instead.

* The ``ForeignObject.get_reverse_joining_columns()`` method is deprecated.

* The default scheme for ``forms.URLField`` will change from ``"http"`` to
  ``"https"`` in Django 6.0. Set :setting:`FORMS_URLFIELD_ASSUME_HTTPS`
  transitional setting to ``True`` to opt into assuming ``"https"`` during the
  Django 5.x release cycle.

* ``FORMS_URLFIELD_ASSUME_HTTPS`` transitional setting is deprecated.

* Support for calling ``format_html()`` without passing args or kwargs will be
  removed.

* Support for ``cx_Oracle`` is deprecated in favor of `oracledb`_ 1.3.2+ Python
  driver.

* ``DatabaseOperations.field_cast_sql()`` is deprecated in favor of
  ``DatabaseOperations.lookup_cast()``. Starting with Django 6.0,
  ``BuiltinLookup.process_lhs()`` will no longer call ``field_cast_sql()``.
  Third-party database backends should implement ``lookup_cast()`` instead.

* The ``django.db.models.enums.ChoicesMeta`` metaclass is renamed to
  ``ChoicesType``.

* The ``Prefetch.get_current_queryset()`` method is deprecated.

* The ``get_prefetch_queryset()`` method of related managers and descriptors
  is deprecated. Starting with Django 6.0, ``get_prefetcher()`` and
  ``prefetch_related_objects()`` will no longer fallback to
  ``get_prefetch_queryset()``. Subclasses should implement
  ``get_prefetch_querysets()`` instead.

.. _`oracledb`: https://oracle.github.io/python-oracledb/

Features removed in 5.0
=======================

These features have reached the end of their deprecation cycle and are removed
in Django 5.0.

See :ref:`deprecated-features-4.0` for details on these changes, including how
to remove usage of these features.

* The ``SERIALIZE`` test setting is removed.

* The undocumented ``django.utils.baseconv`` module is removed.

* The undocumented ``django.utils.datetime_safe`` module is removed.

* The default value of the ``USE_TZ`` setting is changed from ``False`` to
  ``True``.

* The default sitemap protocol for sitemaps built outside the context of a
  request is changed from ``'http'`` to ``'https'``.

* The ``extra_tests`` argument for ``DiscoverRunner.build_suite()`` and
  ``DiscoverRunner.run_tests()`` is removed.

* The ``django.contrib.postgres.aggregates.ArrayAgg``, ``JSONBAgg``, and
  ``StringAgg`` aggregates no longer return ``[]``, ``[]``, and ``''``,
  respectively, when there are no rows.

* The ``USE_L10N`` setting is removed.

* The ``USE_DEPRECATED_PYTZ`` transitional setting is removed.

* Support for ``pytz`` timezones is removed.

* The ``is_dst`` argument is removed from:

  * ``QuerySet.datetimes()``
  * ``django.utils.timezone.make_aware()``
  * ``django.db.models.functions.Trunc()``
  * ``django.db.models.functions.TruncSecond()``
  * ``django.db.models.functions.TruncMinute()``
  * ``django.db.models.functions.TruncHour()``
  * ``django.db.models.functions.TruncDay()``
  * ``django.db.models.functions.TruncWeek()``
  * ``django.db.models.functions.TruncMonth()``
  * ``django.db.models.functions.TruncQuarter()``
  * ``django.db.models.functions.TruncYear()``

* The ``django.contrib.gis.admin.GeoModelAdmin`` and ``OSMGeoAdmin`` classes
  are removed.

* The undocumented ``BaseForm._html_output()`` method is removed.

* The ability to return a ``str``, rather than a ``SafeString``, when rendering
  an ``ErrorDict`` and ``ErrorList`` is removed.

See :ref:`deprecated-features-4.1` for details on these changes, including how
to remove usage of these features.

* The ``SitemapIndexItem.__str__()`` method is removed.

* The ``CSRF_COOKIE_MASKED`` transitional setting is removed.

* The ``name`` argument of ``django.utils.functional.cached_property()`` is
  removed.

* The ``opclasses`` argument of
  ``django.contrib.postgres.constraints.ExclusionConstraint`` is removed.

* The undocumented ability to pass ``errors=None`` to
  ``SimpleTestCase.assertFormError()`` and ``assertFormsetError()`` is removed.

* ``django.contrib.sessions.serializers.PickleSerializer`` is removed.

* The usage of ``QuerySet.iterator()`` on a queryset that prefetches related
  objects without providing the ``chunk_size`` argument is no longer allowed.

* Passing unsaved model instances to related filters is no longer allowed.

* ``created=True`` is required in the signature of
  ``RemoteUserBackend.configure_user()`` subclasses.

* Support for logging out via ``GET`` requests in the
  ``django.contrib.auth.views.LogoutView`` and
  ``django.contrib.auth.views.logout_then_login()`` is removed.

* The ``django.utils.timezone.utc`` alias to ``datetime.timezone.utc`` is
  removed.

* Passing a response object and a form/formset name to
  ``SimpleTestCase.assertFormError()`` and ``assertFormSetError()`` is no
  longer allowed.

* The ``django.contrib.gis.admin.OpenLayersWidget`` is removed.

+ The ``django.contrib.auth.hashers.CryptPasswordHasher`` is removed.

* The ``"django/forms/default.html"`` and
  ``"django/forms/formsets/default.html"`` templates are removed.

* The default form and formset rendering style is changed to the div-based.

* Passing ``nulls_first=False`` or ``nulls_last=False`` to ``Expression.asc()``
  and ``Expression.desc()`` methods, and the ``OrderBy`` expression is no
  longer allowed.