Django 1.9 release notes

December 1, 2015

Welcome to Django 1.9!

These release notes cover the new features, as well as some backwards incompatible changes you’ll want to be aware of when upgrading from Django 1.8 or older versions. We’ve dropped some features that have reached the end of their deprecation cycle, and we’ve begun the deprecation process for some features.

如果你要更新现有的项目，请看 升级 Django 到最新的版本 指南。

Python 兼容性

Django 1.9 requires Python 2.7, 3.4, or 3.5. We highly recommend and only officially support the latest release of each series.

The Django 1.8 series is the last to support Python 3.2 and 3.3.

What’s new in Django 1.9

Performing actions after a transaction commit

The new on_commit() hook allows performing actions after a database transaction is successfully committed. This is useful for tasks such as sending notification emails, creating queued tasks, or invalidating caches.

This functionality from the django-transaction-hooks package has been integrated into Django.

密码验证

Django now offers password validation to help prevent the usage of weak passwords by users. The validation is integrated in the included password change and reset forms and is simple to integrate in any other code. Validation is performed by one or more validators, configured in the new AUTH_PASSWORD_VALIDATORS setting.

Four validators are included in Django, which can enforce a minimum length, compare the password to the user’s attributes like their name, ensure passwords aren’t entirely numeric, or check against an included list of common passwords. You can combine multiple validators, and some validators have custom configuration options. For example, you can choose to provide a custom list of common passwords. Each validator provides a help text to explain its requirements to the user.

By default, no validation is performed and all passwords are accepted, so if you don’t set AUTH_PASSWORD_VALIDATORS, you will not see any change. In new projects created with the default startproject template, a simple set of validators is enabled. To enable basic validation in the included auth forms for your project, you could set, for example:

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]

See 密码验证 for more details.

Permission mixins for class-based views

Django now ships with the mixins AccessMixin, LoginRequiredMixin, PermissionRequiredMixin, and UserPassesTestMixin to provide the functionality of the django.contrib.auth.decorators for class-based views. These mixins have been taken from, or are at least inspired by, the django-braces project.

There are a few differences between Django’s and django-braces‘ implementation, though:

• The raise_exception attribute can only be True or False. Custom exceptions or callables are not supported.
• The handle_no_permission() method does not take a request argument. The current request is available in self.request.
• The custom test_func() of UserPassesTestMixin does not take a user argument. The current user is available in self.request.user.
• The permission_required attribute supports a string (defining one permission) or a list/tuple of strings (defining multiple permissions) that need to be fulfilled to grant access.
• The new permission_denied_message attribute allows passing a message to the PermissionDenied exception.

New styling for contrib.admin

The admin sports a modern, flat design with new SVG icons which look perfect on HiDPI screens. It still provides a fully-functional experience to YUI’s A-grade browsers. Older browser may experience varying levels of graceful degradation.

并行运行测试

The test command now supports a --parallel option to run a project’s tests in multiple processes in parallel.

每个进程都会得到它们自己的数据库。你必须确保不同的测试用例不会访问相同的资源。例如，接触文件系统的测试用例应该创建一个临时目录供自己使用。

This option is enabled by default for Django’s own test suite provided:

• the OS supports it (all but Windows)
• the database backend supports it (all the built-in backends but Oracle)

次要特性

django.contrib.admin

• Admin views now have model_admin or admin_site attributes.
• The URL of the admin change view has been changed (was at /admin/<app>/<model>/<pk>/ by default and is now at /admin/<app>/<model>/<pk>/change/). This should not affect your application unless you have hardcoded admin URLs. In that case, replace those links by reversing admin URLs instead. Note that the old URL still redirects to the new one for backwards compatibility, but it may be removed in a future version.
• ModelAdmin.get_list_select_related() was added to allow changing the select_related() values used in the admin’s changelist query based on the request.
• The available_apps context variable, which lists the available applications for the current user, has been added to the AdminSite.each_context() method.
• AdminSite.empty_value_display and ModelAdmin.empty_value_display were added to override the display of empty values in admin change list. You can also customize the value for each field.
• Added jQuery events when an inline form is added or removed on the change form page.
• The time picker widget includes a ‘6 p.m’ option for consistency of having predefined options every 6 hours.
• JavaScript slug generation now supports Romanian characters.

django.contrib.admindocs

• The model section of the admindocs now also describes methods that take arguments, rather than ignoring them.

django.contrib.auth

• The default iteration count for the PBKDF2 password hasher has been increased by 20%. This backwards compatible change will not affect users who have subclassed django.contrib.auth.hashers.PBKDF2PasswordHasher to change the default value.
• The BCryptSHA256PasswordHasher will now update passwords if its rounds attribute is changed.
• AbstractBaseUser and BaseUserManager were moved to a new django.contrib.auth.base_user module so that they can be imported without including django.contrib.auth in INSTALLED_APPS (doing so raised a deprecation warning in older versions and is no longer supported in Django 1.9).
• The permission argument of permission_required() accepts all kinds of iterables, not only list and tuples.
• The new PersistentRemoteUserMiddleware makes it possible to use REMOTE_USER for setups where the header is only populated on login pages instead of every request in the session.
• The django.contrib.auth.views.password_reset() view accepts an extra_email_context parameter.

django.contrib.contenttypes

• It’s now possible to use order_with_respect_to with a GenericForeignKey.

django.contrib.gis

• All GeoQuerySet methods have been deprecated and replaced by equivalent database functions. As soon as the legacy methods have been replaced in your code, you should even be able to remove the special GeoManager from your GIS-enabled classes.
• The GDAL interface now supports instantiating file-based and in-memory GDALRaster objects from raw data. Setters for raster properties such as projection or pixel values have been added.
• For PostGIS users, the new RasterField allows storing GDALRaster objects. It supports automatic spatial index creation and reprojection when saving a model. It does not yet support spatial querying.
• The new GDALRaster.warp() method allows warping a raster by specifying target raster properties such as origin, width, height, or pixel size (among others).
• The new GDALRaster.transform() method allows transforming a raster into a different spatial reference system by specifying a target srid.
• The new GeoIP2 class allows using MaxMind’s GeoLite2 databases which includes support for IPv6 addresses.
• The default OpenLayers library version included in widgets has been updated from 2.13 to 2.13.1.

django.contrib.postgres

• Added support for the rangefield.contained_by lookup for some built in fields which correspond to the range fields.
• Added JSONField.
• Added PostgreSQL 特有聚合函数.
• Added the TransactionNow database function.

django.contrib.sessions

• The session model and SessionStore classes for the db and cached_db backends are refactored to allow a custom database session backend to build upon them. See 扩展数据库支持的会话引擎 for more details.

django.contrib.sites

• get_current_site() now handles the case where request.get_host() returns domain:port, e.g. example.com:80. If the lookup fails because the host does not match a record in the database and the host has a port, the port is stripped and the lookup is retried with the domain part only.

django.contrib.syndication

• Support for multiple enclosures per feed item has been added. If multiple enclosures are defined on a RSS feed, an exception is raised as RSS feeds, unlike Atom feeds, do not support multiple enclosures per feed item.

缓存

• django.core.cache.backends.base.BaseCache now has a get_or_set() method.
• django.views.decorators.cache.never_cache() now sends more persuasive headers (added no-cache, no-store, must-revalidate to Cache-Control) to better prevent caching. This was also added in Django 1.8.8.

CSRF

• The request header’s name used for CSRF authentication can be customized with CSRF_HEADER_NAME.
• The CSRF referer header is now validated against the CSRF_COOKIE_DOMAIN setting if set. See 工作方式 for details.
• The new CSRF_TRUSTED_ORIGINS setting provides a way to allow cross-origin unsafe requests (e.g. POST) over HTTPS.

Database backends

• The PostgreSQL backend (django.db.backends.postgresql_psycopg2) is also available as django.db.backends.postgresql. The old name will continue to be available for backwards compatibility.

文件存储

• Storage.get_valid_name() is now called when the upload_to is a callable.
• File now has the seekable() method when using Python 3.

表单

• ModelForm accepts the new Meta option field_classes to customize the type of the fields. See 覆盖默认字段 for details.
• You can now specify the order in which form fields are rendered with the field_order attribute, the field_order constructor argument , or the order_fields() method.
• A form prefix can be specified inside a form class, not only when instantiating a form. See 表单前缀 for details.
• You can now specify keyword arguments that you want to pass to the constructor of forms in a formset.
• SlugField now accepts an allow_unicode argument to allow Unicode characters in slugs.
• CharField now accepts a strip argument to strip input data of leading and trailing whitespace. As this defaults to True this is different behavior from previous releases.
• Form fields now support the disabled argument, allowing the field widget to be displayed disabled by browsers.
• It’s now possible to customize bound fields by overriding a field’s get_bound_field() method.

Generic Views

• Class-based views generated using as_view() now have view_class and view_initkwargs attributes.
• method_decorator() can now be used with a list or tuple of decorators. It can also be used to decorate classes instead of methods.

国际化

• The django.views.i18n.set_language() view now properly redirects to translated URLs, when available.
• The django.views.i18n.javascript_catalog() view now works correctly if used multiple times with different configurations on the same page.
• The django.utils.timezone.make_aware() function gained an is_dst argument to help resolve ambiguous times during DST transitions.
• You can now use locale variants supported by gettext. These are usually used for languages which can be written in different scripts, for example Latin and Cyrillic (e.g. be@latin).
• Added the django.views.i18n.json_catalog() view to help build a custom client-side i18n library upon Django translations. It returns a JSON object containing a translations catalog, formatting settings, and a plural rule.
• Added the name_translated attribute to the object returned by the get_language_info template tag. Also added a corresponding template filter: language_name_translated.
• You can now run compilemessages from the root directory of your project and it will find all the app message files that were created by makemessages.
• makemessages now calls xgettext once per locale directory rather than once per translatable file. This speeds up localization builds.
• blocktrans supports assigning its output to a variable using asvar.
• Two new languages are available: Colombian Spanish and Scottish Gaelic.

管理命令

• The new sendtestemail command lets you send a test email to easily confirm that email sending through Django is working.
• To increase the readability of the SQL code generated by sqlmigrate, the SQL code generated for each migration operation is preceded by the operation’s description.
• The dumpdata command output is now deterministically ordered. Moreover, when the --output option is specified, it also shows a progress bar in the terminal.
• The createcachetable command now has a --dry-run flag to print out the SQL rather than execute it.
• The startapp command creates an apps.py file. Since it doesn’t use default_app_config (a discouraged API), you must specify the app config’s path, e.g. 'polls.apps.PollsConfig', in INSTALLED_APPS for it to be used (instead of just 'polls').
• When using the PostgreSQL backend, the dbshell command can connect to the database using the password from your settings file (instead of requiring it to be manually entered).
• The django package may be run as a script, i.e. python -m django, which will behave the same as django-admin.
• Management commands that have the --noinput option now also take --no-input as an alias for that option.

迁移

• Initial migrations are now marked with an initial = True class attribute which allows migrate --fake-initial to more easily detect initial migrations.

• Added support for serialization of functools.partial and LazyObject instances.

• When supplying None as a value in MIGRATION_MODULES, Django will consider the app an app without migrations.

• When applying migrations, the “Rendering model states” step that’s displayed when running migrate with verbosity 2 or higher now computes only the states for the migrations that have already been applied. The model states for migrations being applied are generated on demand, drastically reducing the amount of required memory.

  However, this improvement is not available when unapplying migrations and therefore still requires the precomputation and storage of the intermediate migration states.

  This improvement also requires that Django no longer supports mixed migration plans. Mixed plans consist of a list of migrations where some are being applied and others are being unapplied. This was never officially supported and never had a public API that supports this behavior.

• The squashmigrations command now supports specifying the starting migration from which migrations will be squashed.

模型

• QuerySet.bulk_create() now works on proxy models.
• Database configuration gained a TIME_ZONE option for interacting with databases that store datetimes in local time and don’t support time zones when USE_TZ is True.
• Added the RelatedManager.set() method to the related managers created by ForeignKey, GenericForeignKey, and ManyToManyField.
• The add() method on a reverse foreign key now has a bulk parameter to allow executing one query regardless of the number of objects being added rather than one query per object.
• Added the keep_parents parameter to Model.delete() to allow deleting only a child’s data in a model that uses multi-table inheritance.
• Model.delete() and QuerySet.delete() return the number of objects deleted.
• Added a system check to prevent defining both Meta.ordering and order_with_respect_to on the same model.
• Date and time lookups can be chained with other lookups (such as exact, gt, lt, etc.). For example: Entry.objects.filter(pub_date__month__gt=6).
• Time lookups (hour, minute, second) are now supported by TimeField for all database backends. Support for backends other than SQLite was added but undocumented in Django 1.7.
• You can specify the output_field parameter of the Avg aggregate in order to aggregate over non-numeric columns, such as DurationField.
• Added the date lookup to DateTimeField to allow querying the field by only the date portion.
• Added the Greatest and Least database functions.
• Added the Now database function, which returns the current date and time.
• Transform is now a subclass of Func() which allows Transforms to be used on the right hand side of an expression, just like regular Funcs. This allows registering some database functions like Length, Lower, and Upper as transforms.
• SlugField now accepts an allow_unicode argument to allow Unicode characters in slugs.
• Added support for referencing annotations in QuerySet.distinct().
• connection.queries shows queries with substituted parameters on SQLite.
• Query expressions can now be used when creating new model instances using save(), create(), and bulk_create().

请求和响应

• Unless HttpResponse.reason_phrase is explicitly set, it now is determined by the current value of HttpResponse.status_code. Modifying the value of status_code outside of the constructor will also modify the value of reason_phrase.
• The debug view now shows details of chained exceptions on Python 3.
• The default 40x error views now accept a second positional parameter, the exception that triggered the view.
• View error handlers now support TemplateResponse, commonly used with class-based views.
• Exceptions raised by the render() method are now passed to the process_exception() method of each middleware.
• Request middleware can now set HttpRequest.urlconf to None to revert any changes made by previous middleware and return to using the ROOT_URLCONF.
• The DISALLOWED_USER_AGENTS check in CommonMiddleware now raises a PermissionDenied exception as opposed to returning an HttpResponseForbidden so that handler403 is invoked.
• Added HttpRequest.get_port() to fetch the originating port of the request.
• Added the json_dumps_params parameter to JsonResponse to allow passing keyword arguments to the json.dumps() call used to generate the response.
• The BrokenLinkEmailsMiddleware now ignores 404s when the referer is equal to the requested URL. To circumvent the empty referer check already implemented, some Web bots set the referer to the requested URL.

模板

• Template tags created with the simple_tag() helper can now store results in a template variable by using the as argument.
• Added a Context.setdefault() method.
• The django.template logger was added and includes the following messages:
  • A DEBUG level message for missing context variables.
  • A WARNING level message for uncaught exceptions raised during the rendering of an {% include %} when debug mode is off (helpful since {% include %} silences the exception and returns an empty string).
• The firstof template tag supports storing the output in a variable using ‘as’.
• Context.update() can now be used as a context manager.
• Django template loaders can now extend templates recursively.
• The debug page template postmortem now include output from each engine that is installed.
• Debug page integration for custom template engines was added.
• The DjangoTemplates backend gained the ability to register libraries and builtins explicitly through the template OPTIONS.
• The timesince and timeuntil filters were improved to deal with leap years when given large time spans.
• The include tag now caches parsed templates objects during template rendering, speeding up reuse in places such as for loops.

测试

• Added the json() method to test client responses to give access to the response body as JSON.
• Added the force_login() method to the test client. Use this method to simulate the effect of a user logging into the site while skipping the authentication and verification steps of login().

URLs

• Regular expression lookaround assertions are now allowed in URL patterns.
• The application namespace can now be set using an app_name attribute on the included module or object. It can also be set by passing a 2-tuple of (<list of patterns>, <application namespace>) as the first argument to include().
• System checks have been added for common URL pattern mistakes.

验证器

• Added django.core.validators.int_list_validator() to generate validators of strings containing integers separated with a custom character.
• EmailValidator now limits the length of domain name labels to 63 characters per RFC 1034.
• Added validate_unicode_slug() to validate slugs that may contain Unicode characters.

Backwards incompatible changes in 1.9

警告

In addition to the changes outlined in this section, be sure to review the Features removed in 1.9 for the features that have reached the end of their deprecation cycle and therefore been removed. If you haven’t updated your code within the deprecation timeline for a given feature, its removal may appear as a backwards incompatible change.

数据库后端 API

• A couple of new tests rely on the ability of the backend to introspect column defaults (returning the result as Field.default). You can set the can_introspect_default database feature to False if your backend doesn’t implement this. You may want to review the implementation on the backends that Django includes for reference (#24245).

• Registering a global adapter or converter at the level of the DB-API module to handle time zone information of datetime values passed as query parameters or returned as query results on databases that don’t support time zones is discouraged. It can conflict with other libraries.

  The recommended way to add a time zone to datetime values fetched from the database is to register a converter for DateTimeField in DatabaseOperations.get_db_converters().

  The needs_datetime_string_cast database feature was removed. Database backends that set it must register a converter instead, as explained above.

• The DatabaseOperations.value_to_db_<type>() methods were renamed to adapt_<type>field_value() to mirror the convert_<type>field_value() methods.

• To use the new date lookup, third-party database backends may need to implement the DatabaseOperations.datetime_cast_date_sql() method.

• The DatabaseOperations.time_extract_sql() method was added. It calls the existing date_extract_sql() method. This method is overridden by the SQLite backend to add time lookups (hour, minute, second) to TimeField, and may be needed by third-party database backends.

• The DatabaseOperations.datetime_cast_sql() method (not to be confused with DatabaseOperations.datetime_cast_date_sql() mentioned above) has been removed. This method served to format dates on Oracle long before 1.0, but hasn’t been overridden by any core backend in years and hasn’t been called anywhere in Django’s code or tests.

• In order to support test parallelization, you must implement the DatabaseCreation._clone_test_db() method and set DatabaseFeatures.can_clone_databases = True. You may have to adjust DatabaseCreation.get_test_db_clone_settings().

Default settings that were tuples are now lists

The default settings in django.conf.global_settings were a combination of lists and tuples. All settings that were formerly tuples are now lists.

is_usable attribute on template loaders is removed

Django template loaders previously required an is_usable attribute to be defined. If a loader was configured in the template settings and this attribute was False, the loader would be silently ignored. In practice, this was only used by the egg loader to detect if setuptools was installed. The is_usable attribute is now removed and the egg loader instead fails at runtime if setuptools is not installed.

Related set direct assignment

Direct assignment of related objects in the ORM used to perform a clear() followed by a call to add(). This caused needlessly large data changes and prevented using the m2m_changed signal to track individual changes in many-to-many relations.

Direct assignment now relies on the new set() method on related managers which by default only processes changes between the existing related set and the one that’s newly assigned. The previous behavior can be restored by replacing direct assignment by a call to set() with the keyword argument clear=True.

ModelForm, and therefore ModelAdmin, internally rely on direct assignment for many-to-many relations and as a consequence now use the new behavior.

Filesystem-based template loaders catch more specific exceptions

When using the filesystem.Loader or app_directories.Loader template loaders, earlier versions of Django raised a TemplateDoesNotExist error if a template source existed but was unreadable. This could happen under many circumstances, such as if Django didn’t have permissions to open the file, or if the template source was a directory. Now, Django only silences the exception if the template source does not exist. All other situations result in the original IOError being raised.

HTTP redirects no longer forced to absolute URIs

Relative redirects are no longer converted to absolute URIs. RFC 2616 required the Location header in redirect responses to be an absolute URI, but it has been superseded by RFC 7231 which allows relative URIs in Location, recognizing the actual practice of user agents, almost all of which support them.

Consequently, the expected URLs passed to assertRedirects should generally no longer include the scheme and domain part of the URLs. For example, self.assertRedirects(response, 'http://testserver/some-url/') should be replaced by self.assertRedirects(response, '/some-url/') (unless the redirection specifically contained an absolute URL).

In the rare case that you need the old behavior (discovered with an ancient version of Apache with mod_scgi that interprets a relative redirect as an “internal redirect”), you can restore it by writing a custom middleware:

class LocationHeaderFix(object):
    def process_response(self, request, response):
        if 'Location' in response:
            response['Location'] = request.build_absolute_uri(response['Location'])
        return response

Dropped support for PostgreSQL 9.0

Upstream support for PostgreSQL 9.0 ended in September 2015. As a consequence, Django 1.9 sets 9.1 as the minimum PostgreSQL version it officially supports.

Dropped support for Oracle 11.1

Upstream support for Oracle 11.1 ended in August 2015. As a consequence, Django 1.9 sets 11.2 as the minimum Oracle version it officially supports.

Bulk behavior of add() method of related managers

To improve performance, the add() methods of the related managers created by ForeignKey and GenericForeignKey changed from a series of Model.save() calls to a single QuerySet.update() call. The change means that pre_save and post_save signals aren’t sent anymore. You can use the bulk=False keyword argument to revert to the previous behavior.

Template LoaderOrigin and StringOrigin are removed

In previous versions of Django, when a template engine was initialized with debug as True, an instance of django.template.loader.LoaderOrigin or django.template.base.StringOrigin was set as the origin attribute on the template object. These classes have been combined into Origin and is now always set regardless of the engine debug setting. For a minimal level of backwards compatibility, the old class names will be kept as aliases to the new Origin class until Django 2.0.

Changes to the default logging configuration

To make it easier to write custom logging configurations, Django’s default logging configuration no longer defines django.request and django.security loggers. Instead, it defines a single django logger, filtered at the INFO level, with two handlers:

• console: filtered at the INFO level and only active if DEBUG=True.
• mail_admins: filtered at the ERROR level and only active if DEBUG=False.

If you aren’t overriding Django’s default logging, you should see minimal changes in behavior, but you might see some new logging to the runserver console, for example.

If you are overriding Django’s default logging, you should check to see how your configuration merges with the new defaults.

HttpRequest details in error reporting

It was redundant to display the full details of the HttpRequest each time it appeared as a stack frame variable in the HTML version of the debug page and error email. Thus, the HTTP request will now display the same standard representation as other variables (repr(request)). As a result, the ExceptionReporterFilter.get_request_repr() method and the undocumented django.http.build_request_repr() function were removed.

The contents of the text version of the email were modified to provide a traceback of the same structure as in the case of AJAX requests. The traceback details are rendered by the ExceptionReporter.get_traceback_text() method.

Removal of time zone aware global adapters and converters for datetimes

Django no longer registers global adapters and converters for managing time zone information on datetime values sent to the database as query parameters or read from the database in query results. This change affects projects that meet all the following conditions:

• The USE_TZ setting is True.
• The database is SQLite, MySQL, Oracle, or a third-party database that doesn’t support time zones. In doubt, you can check the value of connection.features.supports_timezones.
• The code queries the database outside of the ORM, typically with cursor.execute(sql, params).

If you’re passing aware datetime parameters to such queries, you should turn them into naive datetimes in UTC:

from django.utils import timezone
param = timezone.make_naive(param, timezone.utc)

If you fail to do so, the conversion will be performed as in earlier versions (with a deprecation warning) up until Django 1.11. Django 2.0 won’t perform any conversion, which may result in data corruption.

If you’re reading datetime values from the results, they will be naive instead of aware. You can compensate as follows:

from django.utils import timezone
value = timezone.make_aware(value, timezone.utc)

You don’t need any of this if you’re querying the database through the ORM, even if you’re using raw() queries. The ORM takes care of managing time zone information.

Template tag modules are imported when templates are configured

The DjangoTemplates backend now performs discovery on installed template tag modules when instantiated. This update enables libraries to be provided explicitly via the 'libraries' key of OPTIONS when defining a DjangoTemplates backend. Import or syntax errors in template tag modules now fail early at instantiation time rather than when a template with a {% load %} tag is first compiled.

django.template.base.add_to_builtins() is removed

Although it was a private API, projects commonly used add_to_builtins() to make template tags and filters available without using the {% load %} tag. This API has been formalized. Projects should now define built-in libraries via the 'builtins' key of OPTIONS when defining a DjangoTemplates backend.

simple_tag now wraps tag output in conditional_escape

In general, template tags do not autoescape their contents, and this behavior is documented. For tags like inclusion_tag, this is not a problem because the included template will perform autoescaping. For assignment_tag(), the output will be escaped when it is used as a variable in the template.

For the intended use cases of simple_tag, however, it is very easy to end up with incorrect HTML and possibly an XSS exploit. For example:

@register.simple_tag(takes_context=True)
def greeting(context):
    return "Hello {0}!".format(context['request'].user.first_name)

In older versions of Django, this will be an XSS issue because user.first_name is not escaped.

In Django 1.9, this is fixed: if the template context has autoescape=True set (the default), then simple_tag will wrap the output of the tag function with conditional_escape().

To fix your simple_tags, it is best to apply the following practices:

• Any code that generates HTML should use either the template system or format_html().
• If the output of a simple_tag needs escaping, use escape() or conditional_escape().
• If you are absolutely certain that you are outputting HTML from a trusted source (e.g. a CMS field that stores HTML entered by admins), you can mark it as such using mark_safe().

Tags that follow these rules will be correct and safe whether they are run on Django 1.9+ or earlier.

Paginator.page_range

Paginator.page_range is now an iterator instead of a list.

In versions of Django previous to 1.8, Paginator.page_range returned a list in Python 2 and a range in Python 3. Django 1.8 consistently returned a list, but an iterator is more efficient.

Existing code that depends on list specific features, such as indexing, can be ported by converting the iterator into a list using list().

Implicit QuerySet __in lookup removed

In earlier versions, queries such as:

Model.objects.filter(related_id=RelatedModel.objects.all())

would implicitly convert to:

Model.objects.filter(related_id__in=RelatedModel.objects.all())

resulting in SQL like "related_id IN (SELECT id FROM ...)".

This implicit __in no longer happens so the “IN” SQL is now “=”, and if the subquery returns multiple results, at least some databases will throw an error.

contrib.admin 浏览器支持

The admin no longer supports Internet Explorer 8 and below, as these browsers have reached end-of-life.

CSS and images to support Internet Explorer 6 and 7 have been removed. PNG and GIF icons have been replaced with SVG icons, which are not supported by Internet Explorer 8 and earlier.

The jQuery library embedded in the admin has been upgraded from version 1.11.2 to 2.1.4. jQuery 2.x has the same API as jQuery 1.x, but does not support Internet Explorer 6, 7, or 8, allowing for better performance and a smaller file size. If you need to support IE8 and must also use the latest version of Django, you can override the admin’s copy of jQuery with your own by creating a Django application with this structure:

app/static/admin/js/vendor/
    jquery.js
    jquery.min.js

SyntaxError when installing Django setuptools 5.5.x

When installing Django 1.9 or 1.9.1 with setuptools 5.5.x, you’ll see:

Compiling django/conf/app_template/apps.py ...
  File "django/conf/app_template/apps.py", line 4
    class {{ camel_case_app_name }}Config(AppConfig):
          ^
SyntaxError: invalid syntax
Compiling django/conf/app_template/models.py ...
  File "django/conf/app_template/models.py", line 1
    {{ unicode_literals }}from django.db import models
                             ^
SyntaxError: invalid syntax

It’s safe to ignore these errors (Django will still install just fine), but you can avoid them by upgrading setuptools to a more recent version. If you’re using pip, you can upgrade pip using python -m pip install -U pip which will also upgrade setuptools. This is resolved in later versions of Django as described in the Django 1.9.2 release notes.

杂项

• The jQuery static files in contrib.admin have been moved into a vendor/jquery subdirectory.
• The text displayed for null columns in the admin changelist list_display cells has changed from (None) (or its translated equivalent) to - (a dash).
• django.http.responses.REASON_PHRASES and django.core.handlers.wsgi.STATUS_CODE_TEXT have been removed. Use Python’s stdlib instead: http.client.responses for Python 3 and httplib.responses for Python 2.
• ValuesQuerySet and ValuesListQuerySet have been removed.
• The admin/base.html template no longer sets window.__admin_media_prefix__ or window.__admin_utc_offset__. Image references in JavaScript that used that value to construct absolute URLs have been moved to CSS for easier customization. The UTC offset is stored on a data attribute of the <body> tag.
• CommaSeparatedIntegerField validation has been refined to forbid values like ',', ',1', and '1,,2'.
• Form initialization was moved from the ProcessFormView.get() method to the new FormMixin.get_context_data() method. This may be backwards incompatible if you have overridden the get_context_data() method without calling super().
• Support for PostGIS 1.5 has been dropped.
• The django.contrib.sites.models.Site.domain field was changed to be unique.
• In order to enforce test isolation, database queries are not allowed by default in SimpleTestCase tests anymore. You can disable this behavior by setting the allow_database_queries class attribute to True on your test class.
• ResolverMatch.app_name was changed to contain the full namespace path in the case of nested namespaces. For consistency with ResolverMatch.namespace, the empty value is now an empty string instead of None.
• For security hardening, session keys must be at least 8 characters.
• Private function django.utils.functional.total_ordering() has been removed. It contained a workaround for a functools.total_ordering() bug in Python versions older than 2.7.3.
• XML serialization (either through dumpdata or the syndication framework) used to output any characters it received. Now if the content to be serialized contains any control characters not allowed in the XML 1.0 standard, the serialization will fail with a ValueError.
• CharField now strips input of leading and trailing whitespace by default. This can be disabled by setting the new strip argument to False.
• Template text that is translated and uses two or more consecutive percent signs, e.g. "%%", may have a new msgid after makemessages is run (most likely the translation will be marked fuzzy). The new msgid will be marked "#, python-format".
• If neither request.current_app nor Context.current_app are set, the url template tag will now use the namespace of the current request. Set request.current_app to None if you don’t want to use a namespace hint.
• The SILENCED_SYSTEM_CHECKS setting now silences messages of all levels. Previously, messages of ERROR level or higher were printed to the console.
• The FlatPage.enable_comments field is removed from the FlatPageAdmin as it’s unused by the application. If your project or a third-party app makes use of it, create a custom ModelAdmin to add it back.
• The return value of setup_databases() and the first argument of teardown_databases() changed. They used to be (old_names, mirrors) tuples. Now they’re just the first item, old_names.
• By default LiveServerTestCase attempts to find an available port in the 8081-8179 range instead of just trying port 8081.
• The system checks for ModelAdmin now check instances rather than classes.
• The private API to apply mixed migration plans has been dropped for performance reasons. Mixed plans consist of a list of migrations where some are being applied and others are being unapplied.
• The related model object descriptor classes in django.db.models.fields.related (private API) are moved from the related module to related_descriptors and renamed as follows:
  • ReverseSingleRelatedObjectDescriptor is ForwardManyToOneDescriptor
  • SingleRelatedObjectDescriptor is ReverseOneToOneDescriptor
  • ForeignRelatedObjectsDescriptor is ReverseManyToOneDescriptor
  • ManyRelatedObjectsDescriptor is ManyToManyDescriptor
• If you implement a custom handler404 view, it must return a response with an HTTP 404 status code. Use HttpResponseNotFound or pass status=404 to the HttpResponse. Otherwise, APPEND_SLASH won’t work correctly with DEBUG=False.

Features deprecated in 1.9

assignment_tag()

Django 1.4 added the assignment_tag helper to ease the creation of template tags that store results in a template variable. The simple_tag() helper has gained this same ability, making the assignment_tag obsolete. Tags that use assignment_tag should be updated to use simple_tag.

{% cycle %} syntax with comma-separated arguments

The cycle tag supports an inferior old syntax from previous Django versions:

{% cycle row1,row2,row3 %}

Its parsing caused bugs with the current syntax, so support for the old syntax will be removed in Django 1.10 following an accelerated deprecation.

ForeignKey and OneToOneField on_delete argument

In order to increase awareness about cascading model deletion, the on_delete argument of ForeignKey and OneToOneField will be required in Django 2.0.

Update models and existing migrations to explicitly set the argument. Since the default is models.CASCADE, add on_delete=models.CASCADE to all ForeignKey and OneToOneFields that don’t use a different option. You can also pass it as the second positional argument if you don’t care about compatibility with older versions of Django.

Field.rel changes

Field.rel and its methods and attributes have changed to match the related fields API. The Field.rel attribute is renamed to remote_field and many of its methods and attributes are either changed or renamed.

The aim of these changes is to provide a documented API for relation fields.

GeoManager and GeoQuerySet custom methods

All custom GeoQuerySet methods (area(), distance(), gml(), …) have been replaced by equivalent geographic expressions in annotations (see in new features). Hence the need to set a custom GeoManager to GIS-enabled models is now obsolete. As soon as your code doesn’t call any of the deprecated methods, you can simply remove the objects = GeoManager() lines from your models.

Template loader APIs have changed

Django template loaders have been updated to allow recursive template extending. This change necessitated a new template loader API. The old load_template() and load_template_sources() methods are now deprecated. Details about the new API can be found in the template loader documentation.

Passing a 3-tuple or an app_name to include()

The instance namespace part of passing a tuple as an argument to include() has been replaced by passing the namespace argument to include(). For example:

polls_patterns = [
     url(...),
]
urlpatterns = [
    url(r'^polls/', include((polls_patterns, 'polls', 'author-polls'))),
]

becomes:

polls_patterns = ([
     url(...),
], 'polls')  # 'polls' is the app_name
urlpatterns = [
    url(r'^polls/', include(polls_patterns, namespace='author-polls')),
]

The app_name argument to include() has been replaced by passing a 2-tuple (as above), or passing an object or module with an app_name attribute (as below). If the app_name is set in this new way, the namespace argument is no longer required. It will default to the value of app_name. For example, the URL patterns in the tutorial are changed from:

mysite/urls.py

urlpatterns = [
    url(r'^polls/', include('polls.urls', namespace="polls")),
    ...
]

to:

mysite/urls.py

urlpatterns = [
    url(r'^polls/', include('polls.urls')),  # 'namespace="polls"' removed
    ...
]

polls/urls.py

app_name = 'polls'  # added
urlpatterns = [...]

This change also means that the old way of including an AdminSite instance is deprecated. Instead, pass admin.site.urls directly to django.conf.urls.url():

urls.py

from django.conf.urls import url
from django.contrib import admin
urlpatterns = [
    url(r'^admin/', admin.site.urls),
]

URL application namespace required if setting an instance namespace

In the past, an instance namespace without an application namespace would serve the same purpose as the application namespace, but it was impossible to reverse the patterns if there was an application namespace with the same name. Includes that specify an instance namespace require that the included URLconf sets an application namespace.

current_app parameter to contrib.auth views

All views in django.contrib.auth.views have the following structure:

def view(request, ..., current_app=None, ...):
    ...
    if current_app is not None:
        request.current_app = current_app
    return TemplateResponse(request, template_name, context)

As of Django 1.8, current_app is set on the request object. For consistency, these views will require the caller to set current_app on the request instead of passing it in a separate argument.

django.contrib.gis.geoip

The django.contrib.gis.geoip2 module supersedes django.contrib.gis.geoip. The new module provides a similar API except that it doesn’t provide the legacy GeoIP-Python API compatibility methods.

杂项

• The weak argument to django.dispatch.signals.Signal.disconnect() has been deprecated as it has no effect.
• The check_aggregate_support() method of django.db.backends.base.BaseDatabaseOperations has been deprecated and will be removed in Django 2.0. The more general check_expression_support() should be used instead.
• django.forms.extras is deprecated. You can find SelectDateWidget in django.forms.widgets (or simply django.forms) instead.
• Private API django.db.models.fields.add_lazy_relation() is deprecated.
• The django.contrib.auth.tests.utils.skipIfCustomUser() decorator is deprecated. With the test discovery changes in Django 1.6, the tests for django.contrib apps are no longer run as part of the user’s project. Therefore, the @skipIfCustomUser decorator is no longer needed to decorate tests in django.contrib.auth.
• If you customized some error handlers, the view signatures with only one request parameter are deprecated. The views should now also accept a second exception positional parameter.
• The django.utils.feedgenerator.Atom1Feed.mime_type and django.utils.feedgenerator.RssFeed.mime_type attributes are deprecated in favor of content_type.
• Signer now issues a warning if an invalid separator is used. This will become an exception in Django 1.10.
• django.db.models.Field._get_val_from_obj() is deprecated in favor of Field.value_from_object().
• django.template.loaders.eggs.Loader is deprecated as distributing applications as eggs is not recommended.
• The callable_obj keyword argument to SimpleTestCase.assertRaisesMessage() is deprecated. Pass the callable as a positional argument instead.
• The allow_tags attribute on methods of ModelAdmin has been deprecated. Use format_html(), format_html_join(), or mark_safe() when constructing the method’s return value instead.
• The enclosure keyword argument to SyndicationFeed.add_item() is deprecated. Use the new enclosures argument which accepts a list of Enclosure objects instead of a single one.
• The django.template.loader.LoaderOrigin and django.template.base.StringOrigin aliases for django.template.base.Origin are deprecated.

Features removed in 1.9

These features have reached the end of their deprecation cycle and are removed in Django 1.9. See Features deprecated in 1.7 for details, including how to remove usage of these features.

• django.utils.dictconfig is removed.
• django.utils.importlib is removed.
• django.utils.tzinfo is removed.
• django.utils.unittest is removed.
• The syncdb command is removed.
• django.db.models.signals.pre_syncdb and django.db.models.signals.post_syncdb is removed.
• Support for allow_syncdb on database routers is removed.
• Automatic syncing of apps without migrations is removed. Migrations are compulsory for all apps unless you pass the migrate --run-syncdb option.
• The SQL management commands for apps without migrations, sql, sqlall, sqlclear, sqldropindexes, and sqlindexes, are removed.
• Support for automatic loading of initial_data fixtures and initial SQL data is removed.
• All models need to be defined inside an installed application or declare an explicit app_label. Furthermore, it isn’t possible to import them before their application is loaded. In particular, it isn’t possible to import models inside the root package of an application.
• The model and form IPAddressField is removed. A stub field remains for compatibility with historical migrations.
• AppCommand.handle_app() is no longer supported.
• RequestSite and get_current_site() are no longer importable from django.contrib.sites.models.
• FastCGI support via the runfcgi management command is removed.
• django.utils.datastructures.SortedDict is removed.
• ModelAdmin.declared_fieldsets is removed.
• The util modules that provided backwards compatibility are removed:
  • django.contrib.admin.util
  • django.contrib.gis.db.backends.util
  • django.db.backends.util
  • django.forms.util
• ModelAdmin.get_formsets is removed.
• The backward compatible shims introduced to rename the BaseMemcachedCache._get_memcache_timeout() method to get_backend_timeout() is removed.
• The --natural and -n options for dumpdata are removed.
• The use_natural_keys argument for serializers.serialize() is removed.
• Private API django.forms.forms.get_declared_fields() is removed.
• The ability to use a SplitDateTimeWidget with DateTimeField is removed.
• The WSGIRequest.REQUEST property is removed.
• The class django.utils.datastructures.MergeDict is removed.
• The zh-cn and zh-tw language codes are removed.
• The internal django.utils.functional.memoize() is removed.
• django.core.cache.get_cache is removed.
• django.db.models.loading is removed.
• Passing callable arguments to querysets is no longer possible.
• BaseCommand.requires_model_validation is removed in favor of requires_system_checks. Admin validators is replaced by admin checks.
• The ModelAdmin.validator_class and default_validator_class attributes are removed.
• ModelAdmin.validate() is removed.
• django.db.backends.DatabaseValidation.validate_field is removed in favor of the check_field method.
• The validate management command is removed.
• django.utils.module_loading.import_by_path is removed in favor of django.utils.module_loading.import_string.
• ssi and url template tags are removed from the future template tag library.
• django.utils.text.javascript_quote() is removed.
• Database test settings as independent entries in the database settings, prefixed by TEST_, are no longer supported.
• The cache_choices option to ModelChoiceField and ModelMultipleChoiceField is removed.
• The default value of the RedirectView.permanent attribute has changed from True to False.
• django.contrib.sitemaps.FlatPageSitemap is removed in favor of django.contrib.flatpages.sitemaps.FlatPageSitemap.
• Private API django.test.utils.TestTemplateLoader is removed.
• The django.contrib.contenttypes.generic module is removed.