# Τεκμηρίωση του Django - 6.0.7

# Django 5.1 release notes

August 7, 2024

Welcome to Django 5.1!

These release notes cover the new features, as well as some backwards incompatible changes you should be aware of when upgrading from Django 5.0 or earlier. We’ve begun the deprecation process for some features.

See the How to upgrade Django to a newer version guide if you’re updating an existing project.

## Python compatibility

Django 5.1 supports Python 3.10, 3.11, 3.12, and 3.13 (as of 5.1.3). We highly recommend and only officially support the latest release of each series.

## What’s new in Django 5.1

### `{% querystring %}` template tag

Django 5.1 introduces the `{% querystring %}` template tag, simplifying the modification of query parameters in URLs, making it easier to generate links that maintain existing query parameters while adding or changing specific ones.

For instance, navigating pagination and query strings in templates can be cumbersome. Consider this template fragment that dynamically generates a URL for navigating to the next page within a paginated view:

    {# Linebreaks added for readability, this should be one, long line. #}
    <a href="?{% for key, values in request.GET.iterlists %}
      {% if key != "page" %}
        {% for value in values %}
          {{ key }}={{ value }}&amp;
        {% endfor %}
      {% endif %}
    {% endfor %}page={{ page.next_page_number }}">Next page</a>

When switching to using this new template tag, the above magically becomes:

    <a href="{% querystring page=page.next_page_number %}">Next page</a>

### PostgreSQL Connection Pools

Django 5.1 also introduces connection pool support for PostgreSQL. As the time to establish a new connection can be relatively long, keeping connections open can reduce latency.

To use a connection pool with psycopg, you can set the `"pool"` option inside `OPTIONS` to be a dict to be passed to `ConnectionPool`, or to `True` to use the `ConnectionPool` defaults:

    DATABASES = {
        "default": {
            "ENGINE": "django.db.backends.postgresql",
            # ...
            "OPTIONS": {
                "pool": {
                    "min_size": 2,
                    "max_size": 4,
                    "timeout": 10,
                }
            },
        },
    }

### Middleware to require authentication by default

The new `LoginRequiredMiddleware` redirects all unauthenticated requests to a login page. Views can allow unauthenticated requests by using the new `login_not_required()` decorator.

`LoginRequiredMiddleware` respects the `login_url` and `redirect_field_name` values set via the `login_required()` decorator, but does not support setting `login_url` or `redirect_field_name` via the `LoginRequiredMixin`.

To enable this, add `"django.contrib.auth.middleware.LoginRequiredMiddleware"` to your `MIDDLEWARE` setting.

### Minor features

#### `django.contrib.admin`

- `ModelAdmin.list_display` now supports using `__` lookups to list fields from related models.

#### `django.contrib.auth`

- The default iteration count for the PBKDF2 password hasher is increased from 720,000 to 870,000.

- The default `parallelism` of the `ScryptPasswordHasher` is increased from 1 to 5, to follow OWASP recommendations.

- The new `AdminUserCreationForm` and the existing `AdminPasswordChangeForm` now support disabling password-based authentication by setting an unusable password on form save. This is now available in the admin when visiting the user creation and password change pages.

- `login_required()`, `permission_required()`, and `user_passes_test()` decorators now support wrapping asynchronous view functions.

- `ReadOnlyPasswordHashWidget` now includes a button to reset the user’s password, which replaces the link previously embedded in the `ReadOnlyPasswordHashField`’s help text, improving the overall accessibility of the `UserChangeForm`.

#### `django.contrib.gis`

- `BoundingCircle` is now supported on SpatiaLite 5.1+.

- `Collect` is now supported on MySQL 8.0.24+.

- `GeoIP2` now allows querying using `ipaddress.IPv4Address` or `ipaddress.IPv6Address` objects.

- `GeoIP2.country()` now exposes the `continent_code`, `continent_name`, and `is_in_european_union` values.

- `GeoIP2.city()` now exposes the `accuracy_radius` and `region_name` values. In addition, the `dma_code` and `region` values are now exposed as `metro_code` and `region_code`, but the previous keys are also retained for backward compatibility.

- `Area` now supports the `ha` unit.

- The new `OGRGeometry.is_3d` attribute allows checking if a geometry has a `Z` coordinate dimension.

- The new `OGRGeometry.set_3d()` method allows addition and removal of the `Z` coordinate dimension.

- `OGRGeometry`, `Point`, `LineString`, `Polygon`, and `GeometryCollection` and its subclasses now support measured geometries via the new `OGRGeometry.is_measured` and `m` properties, and the `OGRGeometry.set_measured()` method.

- `OGRGeometry.centroid` is now available on all supported geometry types.

- `FromWKB()` and `FromWKT()` functions now support the optional `srid` argument (except for Oracle where it is ignored).

#### `django.contrib.postgres`

- `BTreeIndex` now supports the `deduplicate_items` parameter.

#### `django.contrib.sessions`

- `django.contrib.sessions.backends.cached_db.SessionStore` now handles exceptions when storing session information in the cache, logging proper error messages with their traceback via the newly added sessions logger.

- `django.contrib.sessions.backends.base.SessionBase` and all built-in session engines now provide async API. The new asynchronous methods all have `a` prefixed names, e.g. `aget()`, `akeys()`, or `acycle_key()`.

#### Database backends

- `"init_command"` option is now supported in `OPTIONS` on SQLite to allow specifying pragma options to set upon connection.

- `"transaction_mode"` option is now supported in `OPTIONS` on SQLite to allow specifying the Transactions behavior.

- `"pool"` option is now supported in `OPTIONS` on PostgreSQL to allow using connection pools.

#### Error Reporting

- In order to improve accessibility, the technical 404 and 500 error pages now use HTML landmark elements for the header, footer, and main content areas.

#### File Storage

- The `allow_overwrite` parameter of `FileSystemStorage` now allows saving new files over existing ones.

#### Forms

- In order to improve accessibility and enable screen readers to associate fieldsets with their help text, the form fieldset now includes the `aria-describedby` HTML attribute.

#### Management Commands

- The `makemigrations` command now displays meaningful symbols for each operation to highlight `operation categories`.

#### Migrations

- The new `Operation.category` attribute allows specifying an `operation category` used by the `makemigrations` to display a meaningful symbol for the operation.

#### Models

- `QuerySet.explain()` now supports the `generic_plan` option on PostgreSQL 16+.

- `RowRange` now accepts positive integers for the `start` argument and negative integers for the `end` argument.

- The new `exclusion` argument of `RowRange` and `ValueRange` allows excluding rows, groups, and ties from the window frames.

- `QuerySet.order_by()` now supports ordering by annotation transforms such as `JSONObject` keys and `ArrayAgg` indices.

- `F()` and `OuterRef()` expressions that output `CharField`, `EmailField`, `SlugField`, `URLField`, `TextField`, or `ArrayField` can now be sliced.

- The new `from_queryset` argument of `Model.refresh_from_db()` and `Model.arefresh_from_db()` allows customizing the queryset used to reload a model’s value. This can be used to lock the row before reloading or to select related objects.

- The new `Expression.constraint_validation_compatible` attribute allows specifying that the expression should be ignored during a constraint validation.

#### Templates

- Custom tags may now set extra data on the `Parser` object that will later be made available on the `Template` instance. Such data may be used, for example, by the template loader, or other template clients.

- Template engines now implement a `check()` method that is already registered with the check framework.

#### Tests

- `assertContains()`, `assertNotContains()`, and `assertInHTML()` assertions now add haystacks to assertion error messages.

- The `RequestFactory`, `AsyncRequestFactory`, `Client`, and `AsyncClient` classes now support the `query_params` parameter, which accepts a dictionary of query string keys and values. This allows setting query strings on any HTTP methods more easily.

      self.client.post("/items/1", query_params={"action": "delete"})
      await self.async_client.post("/items/1", query_params={"action": "delete"})

- The new `SimpleTestCase.assertNotInHTML()` assertion allows testing that an HTML fragment is not contained in the given HTML haystack.

- In order to enforce test isolation, database connections inside threads are no longer allowed in `SimpleTestCase`.

#### Validators

- The new `DomainNameValidator` validates domain names, including internationalized domain names. The new `validate_domain_name()` function returns an instance of `DomainNameValidator`.

## Backwards incompatible changes in 5.1

### `django.contrib.gis`

- Support for PostGIS 2.5 is removed.

- Support for PROJ < 6 is removed.

- Support for GDAL 2.4 is removed.

- `GeoIP2` no longer opens both city and country databases when a directory path is provided, preferring the city database, if it is available. The country database is a subset of the city database and both are not typically needed. If you require use of the country database when in the same directory as the city database, explicitly pass the country database path to the constructor.

### Dropped support for MariaDB 10.4

Upstream support for MariaDB 10.4 ends in June 2024. Django 5.1 supports MariaDB 10.5 and higher.

### Dropped support for PostgreSQL 12

Upstream support for PostgreSQL 12 ends in November 2024. Django 5.1 supports PostgreSQL 13 and higher.

### Miscellaneous

- In order to improve accessibility, the admin’s changelist filter is now rendered in a `<nav>` tag instead of a `<div>`.

- In order to improve accessibility, the admin’s footer is now rendered in a `<footer>` tag instead of a `<div>`, and also moved below the `<div id="main">` element.

- In order to improve accessibility, the expandable widget used for `ModelAdmin.fieldsets` and `InlineModelAdmin.fieldsets`, when the fieldset has a name and use the `collapse` class, now includes `<details>` and `<summary>` elements.

- The JavaScript file `collapse.js` is removed since it is no longer needed in the Django admin site.

- `SimpleTestCase.assertURLEqual()` and `assertInHTML()` now add `": "` to the `msg_prefix`. This is consistent with the behavior of other assertions.

- `django.utils.text.Truncator` used by `truncatechars_html` and `truncatewords_html` template filters now uses `html.parser.HTMLParser` subclasses. This results in a more robust and faster operation, but there may be small differences in the output.

- The undocumented `django.urls.converters.get_converter()` function is removed.

- The minimum supported version of SQLite is increased from 3.27.0 to 3.31.0.

- `FileField` now raises a `FieldError` when saving a file without a `name`.

- `ImageField.update_dimension_fields(force=True)` is no longer called after saving the image to storage. If your storage backend resizes images, the `width_field` and `height_field` will not match the width and height of the image.

- The minimum supported version of `asgiref` is increased from 3.7.0 to 3.8.1.

- To improve performance, the `delete_selected` admin action now uses `QuerySet.bulk_create()` when creating multiple `LogEntry` objects. As a result, `pre_save` and `post_save` signals for `LogEntry` are not sent when multiple objects are deleted via this admin action.

## Features deprecated in 5.1

### Miscellaneous

- The `ModelAdmin.log_deletion()` and `LogEntryManager.log_action()` methods are deprecated. Subclasses should implement `ModelAdmin.log_deletions()` and `LogEntryManager.log_actions()` instead.

- The undocumented `django.utils.itercompat.is_iterable()` function and the `django.utils.itercompat` module are deprecated. Use `isinstance(..., collections.abc.Iterable)` instead.

- The `django.contrib.gis.geoip2.GeoIP2.coords()` method is deprecated. Use `django.contrib.gis.geoip2.GeoIP2.lon_lat()` instead.

- The `django.contrib.gis.geoip2.GeoIP2.open()` method is deprecated. Use the `GeoIP2` constructor instead.

- Passing positional arguments to `Model.save()` and `Model.asave()` is deprecated in favor of keyword-only arguments.

- Setting `django.contrib.gis.gdal.OGRGeometry.coord_dim` is deprecated. Use `set_3d()` instead.

- Overriding existing converters with `django.urls.register_converter()` is deprecated.

- The `check` keyword argument of `CheckConstraint` is deprecated in favor of `condition`.

- The undocumented `OS_OPEN_FLAGS` property of `FileSystemStorage` is deprecated. To allow overwriting files in storage, set the new `allow_overwrite` option to `True` instead.

- The `get_cache_name()` method of `FieldCacheMixin` is deprecated in favor of the `cache_name` cached property.

## Features removed in 5.1

These features have reached the end of their deprecation cycle and are removed in Django 5.1.

See Features deprecated in 4.2 for details on these changes, including how to remove usage of these features.

- The `BaseUserManager.make_random_password()` method is removed.

- The model’s `Meta.index_together` option is removed.

- The `length_is` template filter is removed.

- The `django.contrib.auth.hashers.SHA1PasswordHasher`, `django.contrib.auth.hashers.UnsaltedSHA1PasswordHasher`, and `django.contrib.auth.hashers.UnsaltedMD5PasswordHasher` are removed.

- The model `django.contrib.postgres.fields.CICharField`, `django.contrib.postgres.fields.CIEmailField`, and `django.contrib.postgres.fields.CITextField` are removed, except for support in historical migrations.

- The `django.contrib.postgres.fields.CIText` mixin is removed.

- The `map_width` and `map_height` attributes of `BaseGeometryWidget` are removed.

- The `SimpleTestCase.assertFormsetError()` method is removed.

- The `TransactionTestCase.assertQuerysetEqual()` method is removed.

- Support for passing encoded JSON string literals to `JSONField` and associated lookups and expressions is removed.

- Support for passing positional arguments to `Signer` and `TimestampSigner` is removed.

- The `DEFAULT_FILE_STORAGE` and `STATICFILES_STORAGE` settings is removed.

- The `django.core.files.storage.get_storage_class()` function is removed.