docs/releases/2.0.txt
========================
Django 2.0 release notes
========================
*December 2, 2017*
Welcome to Django 2.0!
These release notes cover the :ref:`new features <whats-new-2.0>`, as well as
some :ref:`backwards incompatible changes <backwards-incompatible-2.0>` you'll
want to be aware of when upgrading from Django 1.11 or earlier. We've
:ref:`dropped some features<removed-features-2.0>` that have reached the end of
their deprecation cycle, and we've :ref:`begun the deprecation process for some
features <deprecated-features-2.0>`.
This release starts Django's use of a :ref:`loose form of semantic versioning
<internal-release-cadence>`, but there aren't any major backwards incompatible
changes that might be expected of a 2.0 release. Upgrading should be a similar
amount of effort as past feature releases.
See the :doc:`/howto/upgrade-version` guide if you're updating an existing
project.
Python compatibility
====================
Django 2.0 supports Python 3.4, 3.5, 3.6, and 3.7. We **highly recommend** and
only officially support the latest release of each series.
The Django 1.11.x series is the last to support Python 2.7.
Django 2.0 will be the last release series to support Python 3.4. If you plan
a deployment of Python 3.4 beyond the end-of-life for Django 2.0 (April 2019),
stick with Django 1.11 LTS (supported until April 2020) instead. Note, however,
that the end-of-life for Python 3.4 is March 2019.
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 to 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
========================
Simplified URL routing syntax
-----------------------------
The new :func:`django.urls.path()` function allows a simpler, more readable URL
routing syntax. For example, this example from previous Django releases::
url(r"^articles/(?P<year>[0-9]{4})/$", views.year_archive),
could be written as::
path("articles/<int:year>/", views.year_archive),
The new syntax supports type coercion of URL parameters. In the example, the
view will receive the ``year`` keyword argument as an integer rather than as
a string. Also, the URLs that will match are slightly less constrained in the
rewritten example. For example, the year 10000 will now match since the year
integers aren't constrained to be exactly four digits long as they are in the
regular expression.
The ``django.conf.urls.url()`` function from previous versions is now available
as :func:`django.urls.re_path`. The old location remains for backwards
compatibility, without an imminent deprecation. The old
``django.conf.urls.include()`` function is now importable from ``django.urls``
so you can use ``from django.urls import include, path, re_path`` in your
URLconfs.
The :doc:`/topics/http/urls` document is rewritten to feature the new syntax
and provide more details.
Mobile-friendly ``contrib.admin``
---------------------------------
The admin is now responsive and supports all major mobile devices. Older
browsers may experience varying levels of graceful degradation.
Window expressions
------------------
The new :class:`~django.db.models.expressions.Window` expression allows
adding an ``OVER`` clause to querysets. You can use :ref:`window functions
<window-functions>` and :ref:`aggregate functions <aggregation-functions>` in
the expression.
Minor features
--------------
:mod:`django.contrib.admin`
~~~~~~~~~~~~~~~~~~~~~~~~~~~
* The new :attr:`.ModelAdmin.autocomplete_fields` attribute and
:meth:`.ModelAdmin.get_autocomplete_fields` method allow using a
`Select2 <https://select2.org/>`_ search widget for ``ForeignKey`` and
``ManyToManyField``.
:mod:`django.contrib.auth`
~~~~~~~~~~~~~~~~~~~~~~~~~~
* The default iteration count for the PBKDF2 password hasher is increased from
36,000 to 100,000.
:mod:`django.contrib.gis`
~~~~~~~~~~~~~~~~~~~~~~~~~
* Added MySQL support for the
:class:`~django.contrib.gis.db.models.functions.AsGeoJSON` function,
:class:`~django.contrib.gis.db.models.functions.GeoHash` function,
:class:`~django.contrib.gis.db.models.functions.IsValid` function,
:lookup:`isvalid` lookup, and :ref:`distance lookups <distance-lookups>`.
* Added the :class:`~django.contrib.gis.db.models.functions.Azimuth` and
:class:`~django.contrib.gis.db.models.functions.LineLocatePoint` functions,
supported on PostGIS and SpatiaLite.
* Any :class:`~django.contrib.gis.geos.GEOSGeometry` imported from GeoJSON now
has its SRID set.
* Added the :attr:`.OSMWidget.default_zoom` attribute to customize the map's
default zoom level.
* Made metadata readable and editable on rasters through the
:attr:`~django.contrib.gis.gdal.GDALRaster.metadata`,
:attr:`~django.contrib.gis.gdal.GDALRaster.info`, and
:attr:`~django.contrib.gis.gdal.GDALBand.metadata` attributes.
* Allowed passing driver-specific creation options to
:class:`~django.contrib.gis.gdal.GDALRaster` objects using ``papsz_options``.
* Allowed creating :class:`~django.contrib.gis.gdal.GDALRaster` objects in
GDAL's internal virtual filesystem. Rasters can now be :ref:`created from and
converted to binary data <gdal-raster-vsimem>` in-memory.
* The new :meth:`GDALBand.color_interp()
<django.contrib.gis.gdal.GDALBand.color_interp>` method returns the color
interpretation for the band.
:mod:`django.contrib.postgres`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* The new ``distinct`` argument for
:class:`~django.contrib.postgres.aggregates.ArrayAgg` determines if
concatenated values will be distinct.
* The new :class:`~django.contrib.postgres.functions.RandomUUID` database
function returns a version 4 UUID. It requires use of PostgreSQL's
``pgcrypto`` extension which can be activated using the new
:class:`~django.contrib.postgres.operations.CryptoExtension` migration
operation.
* :class:`django.contrib.postgres.indexes.GinIndex` now supports the
``fastupdate`` and ``gin_pending_list_limit`` parameters.
* The new :class:`~django.contrib.postgres.indexes.GistIndex` class allows
creating ``GiST`` indexes in the database. The new
:class:`~django.contrib.postgres.operations.BtreeGistExtension` migration
operation installs the ``btree_gist`` extension to add support for operator
classes that aren't built-in.
* :djadmin:`inspectdb` can now introspect ``JSONField`` and various
``RangeField``\s (``django.contrib.postgres`` must be in ``INSTALLED_APPS``).
:mod:`django.contrib.sitemaps`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Added the ``protocol`` keyword argument to the
:class:`~django.contrib.sitemaps.GenericSitemap` constructor.
Cache
~~~~~
* ``cache.set_many()`` now returns a list of keys that failed to be inserted.
For the built-in backends, failed inserts can only happen on memcached.
File Storage
~~~~~~~~~~~~
* :meth:`File.open() <django.core.files.File.open>` can be used as a context
manager, e.g. ``with file.open() as f:``.
Forms
~~~~~
* The new ``date_attrs`` and ``time_attrs`` arguments for
:class:`~django.forms.SplitDateTimeWidget` and
:class:`~django.forms.SplitHiddenDateTimeWidget` allow specifying different
HTML attributes for the ``DateInput`` and ``TimeInput`` (or hidden)
subwidgets.
* The new :meth:`Form.errors.get_json_data()
<django.forms.Form.errors.get_json_data>` method returns form errors as
a dictionary suitable for including in a JSON response.
Generic Views
~~~~~~~~~~~~~
* The new :attr:`.ContextMixin.extra_context` attribute allows adding context
in ``View.as_view()``.
Management Commands
~~~~~~~~~~~~~~~~~~~
* :djadmin:`inspectdb` now translates MySQL's unsigned integer columns to
``PositiveIntegerField`` or ``PositiveSmallIntegerField``.
* The new :option:`makemessages --add-location` option controls the comment
format in ``.po`` files.
* :djadmin:`loaddata` can now :ref:`read from stdin <loading-fixtures-stdin>`.
* The new :option:`diffsettings --output` option allows formatting the output
in a unified diff format.
* On Oracle, :djadmin:`inspectdb` can now introspect ``AutoField`` if the
column is created as an identity column.
* On MySQL, :djadmin:`dbshell` now supports client-side TLS certificates.
Migrations
~~~~~~~~~~
* The new :option:`squashmigrations --squashed-name` option allows naming the
squashed migration.
Models
~~~~~~
* The new :class:`~django.db.models.functions.StrIndex` database function
finds the starting index of a string inside another string.
* On Oracle, ``AutoField`` and ``BigAutoField`` are now created as `identity
columns <https://docs.oracle.com/en/database/oracle/oracle-database/21/drdaa/
intro-to-tools-and-products-supporting-migraiton.html#GUID-14E4817B-F3BC-4D99
-B471-A0ACDC303CC9>`__.
* The new ``chunk_size`` parameter of :meth:`.QuerySet.iterator` controls the
number of rows fetched by the Python database client when streaming results
from the database. For databases that don't support server-side cursors, it
controls the number of results Django fetches from the database adapter.
* :meth:`.QuerySet.earliest`, :meth:`.QuerySet.latest`, and
:attr:`Meta.get_latest_by <django.db.models.Options.get_latest_by>` now
allow ordering by several fields.
* Added the :class:`~django.db.models.functions.ExtractQuarter` function to
extract the quarter from :class:`~django.db.models.DateField` and
:class:`~django.db.models.DateTimeField`, and exposed it through the
:lookup:`quarter` lookup.
* Added the :class:`~django.db.models.functions.TruncQuarter` function to
truncate :class:`~django.db.models.DateField` and
:class:`~django.db.models.DateTimeField` to the first day of a quarter.
* Added the :attr:`~django.db.models.Index.db_tablespace` parameter to
class-based indexes.
* If the database supports a native duration field (Oracle and PostgreSQL),
:class:`~django.db.models.functions.Extract` now works with
:class:`~django.db.models.DurationField`.
* Added the ``of`` argument to :meth:`.QuerySet.select_for_update()`, supported
on PostgreSQL and Oracle, to lock only rows from specific tables rather than
all selected tables. It may be helpful particularly when
:meth:`~.QuerySet.select_for_update()` is used in conjunction with
:meth:`~.QuerySet.select_related()`.
* The new ``field_name`` parameter of :meth:`.QuerySet.in_bulk` allows fetching
results based on any unique model field.
* :meth:`.CursorWrapper.callproc()` now takes an optional dictionary of keyword
parameters, if the backend supports this feature. Of Django's built-in
backends, only Oracle supports it.
* The new :meth:`connection.execute_wrapper()
<django.db.backends.base.DatabaseWrapper.execute_wrapper>` method allows
:doc:`installing wrappers around execution of database queries
</topics/db/instrumentation>`.
* The new ``filter`` argument for built-in aggregates allows :ref:`adding
different conditionals <conditional-aggregation>` to multiple aggregations
over the same fields or relations.
* Added support for expressions in :attr:`Meta.ordering
<django.db.models.Options.ordering>`.
* The new ``named`` parameter of :meth:`.QuerySet.values_list` allows fetching
results as named tuples.
* The new :class:`.FilteredRelation` class allows adding an ``ON`` clause to
querysets.
Pagination
~~~~~~~~~~
* Added :meth:`Paginator.get_page() <django.core.paginator.Paginator.get_page>`
to provide the documented pattern of handling invalid page numbers.
Requests and Responses
~~~~~~~~~~~~~~~~~~~~~~
* The :djadmin:`runserver` web server supports HTTP 1.1.
Templates
~~~~~~~~~
* To increase the usefulness of :meth:`.Engine.get_default` in third-party
apps, it now returns the first engine if multiple ``DjangoTemplates`` engines
are configured in ``TEMPLATES`` rather than raising ``ImproperlyConfigured``.
* Custom template tags may now accept keyword-only arguments.
Tests
~~~~~
* Added threading support to :class:`~django.test.LiveServerTestCase`.
* Added settings that allow customizing the test tablespace parameters for
Oracle: :setting:`DATAFILE_SIZE`, :setting:`DATAFILE_TMP_SIZE`,
:setting:`DATAFILE_EXTSIZE`, and :setting:`DATAFILE_TMP_EXTSIZE`.
Validators
~~~~~~~~~~
* The new :class:`.ProhibitNullCharactersValidator` disallows the null
character in the input of the :class:`~django.forms.CharField` form field
and its subclasses. Null character input was observed from vulnerability
scanning tools. Most databases silently discard null characters, but
psycopg2 2.7+ raises an exception when trying to save a null character to
a char/text field with PostgreSQL.
.. _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. Python's :option:`-b` option may help detect
that mistake in your code.
For example, ``reverse()`` now uses ``str()`` instead of ``force_text()`` to
coerce the ``args`` and ``kwargs`` it receives, prior to their placement in
the URL. For bytestrings, this creates a string with an undesired ``b`` prefix
as well as additional quotes (``str(b'foo')`` is ``"b'foo'"``). To adapt, call
``decode()`` on the bytestring before passing it to ``reverse()``.
Database backend API
--------------------
This section describes changes that may be needed in third-party database
backends.
* The ``DatabaseOperations.datetime_cast_date_sql()``,
``datetime_cast_time_sql()``, ``datetime_trunc_sql()``,
``datetime_extract_sql()``, and ``date_interval_sql()`` methods now return
only the SQL to perform the operation instead of SQL and a list of
parameters.
* Third-party database backends should add a ``DatabaseWrapper.display_name``
attribute with the name of the database that your backend works with. Django
may use it in various messages, such as in system checks.
* The first argument of ``SchemaEditor._alter_column_type_sql()`` is now
``model`` rather than ``table``.
* The first argument of ``SchemaEditor._create_index_name()`` is now
``table_name`` rather than ``model``.
* To enable ``FOR UPDATE OF`` support, set
``DatabaseFeatures.has_select_for_update_of = True``. If the database
requires that the arguments to ``OF`` be columns rather than tables, set
``DatabaseFeatures.select_for_update_of_column = True``.
* To enable support for :class:`~django.db.models.expressions.Window`
expressions, set ``DatabaseFeatures.supports_over_clause`` to ``True``. You
may need to customize the ``DatabaseOperations.window_start_rows_start_end()``
and/or ``window_start_range_start_end()`` methods.
* Third-party database backends should add a
``DatabaseOperations.cast_char_field_without_max_length`` attribute with the
database data type that will be used in the
:class:`~django.db.models.functions.Cast` function for a ``CharField`` if the
``max_length`` argument isn't provided.
* The first argument of ``DatabaseCreation._clone_test_db()`` and
``get_test_db_clone_settings()`` is now ``suffix`` rather
than ``number`` (in case you want to rename the signatures in your backend
for consistency). ``django.test`` also now passes those values as strings
rather than as integers.
* Third-party database backends should add a
``DatabaseIntrospection.get_sequences()`` method based on the stub in
``BaseDatabaseIntrospection``.
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
<mysql-isolation-level>`, if needed.
:attr:`AbstractUser.last_name <django.contrib.auth.models.User.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)
``QuerySet.reverse()`` and ``last()`` are prohibited after slicing
------------------------------------------------------------------
Calling ``QuerySet.reverse()`` or ``last()`` on a sliced queryset leads to
unexpected results due to the slice being applied after reordering. This is
now prohibited, e.g.:
.. code-block:: pycon
>>> Model.objects.all()[:2].reverse()
Traceback (most recent call last):
...
TypeError: Cannot reverse a query once a slice has been taken.
Form fields no longer accept optional arguments as positional arguments
-----------------------------------------------------------------------
To help prevent runtime errors due to incorrect ordering of form field
arguments, optional arguments of built-in form fields are no longer accepted
as positional arguments. For example::
forms.IntegerField(25, 10)
raises an exception and should be replaced with::
forms.IntegerField(max_value=25, min_value=10)
``call_command()`` validates the options it receives
----------------------------------------------------
``call_command()`` now validates that the argument parser of the command being
called defines all of the options passed to ``call_command()``.
For custom management commands that use options not created using
``parser.add_argument()``, add a ``stealth_options`` attribute on the command::
class MyCommand(BaseCommand):
stealth_options = ("option_name", ...)
Indexes no longer accept positional arguments
---------------------------------------------
For example::
models.Index(["headline", "-pub_date"], "index_name")
raises an exception and should be replaced with::
models.Index(fields=["headline", "-pub_date"], name="index_name")
Foreign key constraints are now enabled on SQLite
-------------------------------------------------
This will appear as a backwards-incompatible change (``IntegrityError:
FOREIGN KEY constraint failed``) if attempting to save an existing model
instance that's violating a foreign key constraint.
Foreign keys are now created with ``DEFERRABLE INITIALLY DEFERRED`` instead of
``DEFERRABLE IMMEDIATE``. Thus, tables may need to be rebuilt to recreate
foreign keys with the new definition, particularly if you're using a pattern
like this::
from django.db import transaction
with transaction.atomic():
Book.objects.create(author_id=1)
Author.objects.create(id=1)
If you don't recreate the foreign key as ``DEFERRED``, the first ``create()``
would fail now that foreign key constraints are enforced.
Backup your database first! After upgrading to Django 2.0, you can then
rebuild tables using a script similar to this::
from django.apps import apps
from django.db import connection
for app in apps.get_app_configs():
for model in app.get_models(include_auto_created=True):
if model._meta.managed and not (model._meta.proxy or model._meta.swapped):
for base in model.__bases__:
if hasattr(base, "_meta"):
base._meta.local_many_to_many = []
model._meta.local_many_to_many = []
with connection.schema_editor() as editor:
editor._remake_table(model)
This script hasn't received extensive testing and needs adaption for various
cases such as multiple databases. Feel free to contribute improvements.
In addition, because of a table alteration limitation of SQLite, it's prohibited
to perform :class:`~django.db.migrations.operations.RenameModel` and
:class:`~django.db.migrations.operations.RenameField` operations on models or
fields referenced by other models in a transaction. In order to allow migrations
containing these operations to be applied, you must set the
``Migration.atomic`` attribute to ``False``.
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.
* :class:`~django.views.generic.base.RedirectView` no longer silences
``NoReverseMatch`` if the ``pattern_name`` doesn't exist.
* When ``USE_L10N`` is off, :class:`~django.forms.FloatField` and
:class:`~django.forms.DecimalField` now respect :setting:`DECIMAL_SEPARATOR`
and :setting:`THOUSAND_SEPARATOR` during validation. For example, with the
settings::
USE_L10N = False
USE_THOUSAND_SEPARATOR = True
DECIMAL_SEPARATOR = ","
THOUSAND_SEPARATOR = "."
an input of ``"1.345"`` is now converted to ``1345`` instead of ``1.345``.
* Subclasses of :class:`~django.contrib.auth.models.AbstractBaseUser` are no
longer required to implement ``get_short_name()`` and ``get_full_name()``.
(The base implementations that raise ``NotImplementedError`` are removed.)
``django.contrib.admin`` uses these methods if implemented but doesn't
require them. Third-party apps that use these methods may want to adopt a
similar approach.
* The ``FIRST_DAY_OF_WEEK`` and ``NUMBER_GROUPING`` format settings are now
kept as integers in JavaScript and JSON i18n view outputs.
* :meth:`~django.test.TransactionTestCase.assertNumQueries` now ignores
connection configuration queries. Previously, if a test opened a new database
connection, those queries could be included as part of the
``assertNumQueries()`` count.
* The default size of the Oracle test tablespace is increased from 20M to 50M
and the default autoextend size is increased from 10M to 25M.
* To improve performance when streaming large result sets from the database,
:meth:`.QuerySet.iterator` now fetches 2000 rows at a time instead of 100.
The old behavior can be restored using the ``chunk_size`` parameter. For
example::
Book.objects.iterator(chunk_size=100)
* Providing unknown package names in the ``packages`` argument of the
:class:`~django.views.i18n.JavaScriptCatalog` view now raises ``ValueError``
instead of passing silently.
* A model instance's primary key now appears in the default ``Model.__str__()``
method, e.g. ``Question object (1)``.
* ``makemigrations`` now detects changes to the model field ``limit_choices_to``
option. Add this to your existing migrations or accept an auto-generated
migration for fields that use it.
* Performing queries that require :ref:`automatic spatial transformations
<automatic-spatial-transformations>` now raises ``NotImplementedError``
on MySQL instead of silently using non-transformed geometries.
* ``django.core.exceptions.DjangoRuntimeWarning`` is removed. It was only used
in the cache backend as an intermediate class in ``CacheKeyWarning``'s
inheritance of ``RuntimeWarning``.
* Renamed ``BaseExpression._output_field`` to ``output_field``. You may need
to update custom expressions.
* In older versions, forms and formsets combine their ``Media`` with widget
``Media`` by concatenating the two. The combining now tries to :ref:`preserve
the relative order of elements in each list <form-media-asset-order>`.
``MediaOrderConflictWarning`` is issued if the order can't be preserved.
* ``django.contrib.gis.gdal.OGRException`` is removed. It's been an alias for
``GDALException`` since Django 1.8.
* Support for GEOS 3.3.x is dropped.
* The way data is selected for ``GeometryField`` is changed to improve
performance, and in raw SQL queries, those fields must now be wrapped in
``connection.ops.select``. See the :ref:`Raw queries note<gis-raw-sql>` in
the GIS tutorial for an example.
.. _deprecated-features-2.0:
Features deprecated in 2.0
==========================
``context`` argument of ``Field.from_db_value()`` and ``Expression.convert_value()``
------------------------------------------------------------------------------------
The ``context`` argument of ``Field.from_db_value()`` and
``Expression.convert_value()`` is unused as it's always an empty dictionary.
The signature of both methods is now::
(self, value, expression, connection)
instead of::
(self, value, expression, connection, context)
Support for the old signature in custom fields and expressions remains until
Django 3.0.
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.
* ``django.shortcuts.render_to_response()`` is deprecated in favor of
:func:`django.shortcuts.render`. ``render()`` takes the same arguments
except that it also requires a ``request``.
* The ``DEFAULT_CONTENT_TYPE`` setting is deprecated. It doesn't interact well
with third-party apps and is obsolete since HTML5 has mostly superseded
XHTML.
* ``HttpRequest.xreadlines()`` is deprecated in favor of iterating over the
request.
* The ``field_name`` keyword argument to :meth:`.QuerySet.earliest` and
:meth:`.QuerySet.latest` is deprecated in favor of passing the field
names as arguments. Write ``.earliest('pub_date')`` instead of
``.earliest(field_name='pub_date')``.
.. _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` for details on these changes, 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`` is now
required in models and migrations. Consider squashing migrations so that you
have fewer of them to update.
* ``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 (including ``admin.site.urls``) 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.
See :ref:`deprecated-features-1.10` for details on these changes.
* 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 in favor of its new
location, ``django.urls``.
* ``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.