# documentação Django 3.1.9.dev

# `django.contrib.auth`

This document provides API reference material for the components of Django’s authentication system. For more details on the usage of these components or how to customize authentication and authorization see the authentication topic guide.

## `User` model

class `models.``User`

### Campos

class `models.``User`

  `User` objects have the following fields:

  `username`

    Required. 150 characters or fewer. Usernames may contain alphanumeric, `_`, `@`, `+`, `.` and `-` characters.

    The `max_length` should be sufficient for many use cases. If you need a longer length, please use a custom user model. If you use MySQL with the `utf8mb4` encoding (recommended for proper Unicode support), specify at most `max_length=191` because MySQL can only create unique indexes with 191 characters in that case by default.

  `first_name`

    Optional (`blank=True`). 150 characters or fewer.

    Changed in Django 3.1:

    The `max_length` increased from 30 to 150 characters.

  `last_name`

    Optional (`blank=True`). 150 characters or fewer.

  `email`

    Optional (`blank=True`). Email address.

  `password`

    Required. A hash of, and metadata about, the password. (Django doesn’t store the raw password.) Raw passwords can be arbitrarily long and can contain any character. See the password documentation.

  `groups`

    Many-to-many relationship to `Group`

  `user_permissions`

    Many-to-many relationship to `Permission`

  `is_staff`

    Boolean. Designates whether this user can access the admin site.

  `is_active`

    Boolean. Designates whether this user account should be considered active. We recommend that you set this flag to `False` instead of deleting accounts; that way, if your applications have any foreign keys to users, the foreign keys won’t break.

    This doesn’t necessarily control whether or not the user can log in. Authentication backends aren’t required to check for the `is_active` flag but the default backend (`ModelBackend`) and the `RemoteUserBackend` do. You can use `AllowAllUsersModelBackend` or `AllowAllUsersRemoteUserBackend` if you want to allow inactive users to login. In this case, you’ll also want to customize the `AuthenticationForm` used by the `LoginView` as it rejects inactive users. Be aware that the permission-checking methods such as `has_perm()` and the authentication in the Django admin all return `False` for inactive users.

  `is_superuser`

    Booleano. Designa que este user tem todas as permissões sem explicitamente assinalá-los.

  `last_login`

    A datetime of the user’s last login.

  `date_joined`

    A datetime designating when the account was created. Is set to the current date/time by default when the account is created.

### Atributos

class `models.``User`
  `is_authenticated`

    Atributo somente de leitura que está sempre definido como `True``(oposto ao `AnonymousUser.is_authenticated` que é sempre `False`. Esta á a maneira de dizer se o usuário foi atenticado. Isso não implica em verificação de nenhuma permissão e não verifica se o usuário é ativo ou tem uma sessão válida. Mesmo que normalmente você irá verificar este atributo no `request.user` para descobrir se foi populado pelo `AuthenticationMiddleware` (representando o usuário logado atualmente), você deve saber se este atributo é `True` para qualquer instância de `User`.

  `is_anonymous`

    Read-only attribute which is always `False`. This is a way of differentiating `User` and `AnonymousUser` objects. Generally, you should prefer using `is_authenticated` to this attribute.

### Métodos

class `models.``User`
  `get_username`()

    Returns the username for the user. Since the `User` model can be swapped out, you should use this method instead of referencing the username attribute directly.

  `get_full_name`()

    Returns the `first_name` plus the `last_name`, with a space in between.

  `get_short_name`()

    Retorna o `first_name`.

  `set_password`(raw_password)

    Sets the user’s password to the given raw string, taking care of the password hashing. Doesn’t save the `User` object.

    When the `raw_password` is `None`, the password will be set to an unusable password, as if `set_unusable_password()` were used.

  `check_password`(raw_password)

    Retorna ``True``se a string simples é a senha correta para o usuário. (leva em conta a criptografia da senha quando fizer a comparação.)

  `set_unusable_password`()

    Marks the user as having no password set. This isn’t the same as having a blank string for a password. `check_password()` for this user will never return `True`. Doesn’t save the `User` object.

    Você talvez precise disso se a autenticação para sua aplicação é feita em uma fonte externa existente como um diretório LDAP.

  `has_usable_password`()

    Returns `False` if `set_unusable_password()` has been called for this user.

  `get_user_permissions`(obj=None)
    New in Django 3.0.

    Returns a set of permission strings that the user has directly.

    If `obj` is passed in, only returns the user permissions for this specific object.

  `get_group_permissions`(obj=None)

    Retorna um conjunto de strings de permissões que o usuário tem, além de seus grupos.

    Se o `obj` passado, somente retorna o grupo de permissões para este objeto específico.

  `get_all_permissions`(obj=None)

    Retorna um conjunto de strings de permissões que o usuário tem, ambas permissões grupo e usuário.

    Se o `obj` é passado, somente retorna as permissões para este objeto específico.

  `has_perm`(perm, obj=None)

    Returns `True` if the user has the specified permission, where perm is in the format `"<app label>.<permission codename>"`. (see documentation on permissions). If the user is inactive, this method will always return `False`. For an active superuser, this method will always return `True`.

    Se `obj` é passado, este método não irá verificar por permissões para o modelo, mas para este objeto específico.

  `has_perms`(perm_list, obj=None)

    Returns `True` if the user has each of the specified permissions, where each perm is in the format `"<app label>.<permission codename>"`. If the user is inactive, this method will always return `False`. For an active superuser, this method will always return `True`.

    Se `obj` é passado, este método não irá verificar por permissões para o modelo, mas para este objeto específico.

  `has_module_perms`(package_name)

    Returns `True` if the user has any permissions in the given package (the Django app label). If the user is inactive, this method will always return `False`. For an active superuser, this method will always return `True`.

  `email_user`(subject, message, from_email=None, **kwargs)

    Sends an email to the user. If `from_email` is `None`, Django uses the `DEFAULT_FROM_EMAIL`. Any `**kwargs` are passed to the underlying `send_mail()` call.

### Manager methods

class `models.``UserManager`

  The `User` model has a custom manager that has the following helper methods (in addition to the methods provided by `BaseUserManager`):

  `create_user`(username, email=None, password=None, **extra_fields)

    Creates, saves and returns a `User`.

    The `username` and `password` are set as given. The domain portion of `email` is automatically converted to lowercase, and the returned `User` object will have `is_active` set to `True`.

    If no password is provided, `set_unusable_password()` will be called.

    The `extra_fields` keyword arguments are passed through to the `User`’s `__init__` method to allow setting arbitrary fields on a custom user model.

    See Creating users for example usage.

  `create_superuser`(username, email=None, password=None, **extra_fields)

    Same as `create_user()`, but sets `is_staff` and `is_superuser` to `True`.

    Changed in Django 3.0:

    The `email` and `password` parameters were made optional.

  `with_perm`(perm, is_active=True, include_superusers=True, backend=None, obj=None)
    New in Django 3.0.

    Returns users that have the given permission `perm` either in the `"<app label>.<permission codename>"` format or as a `Permission` instance. Returns an empty queryset if no users who have the `perm` found.

    If `is_active` is `True` (default), returns only active users, or if `False`, returns only inactive users. Use `None` to return all users irrespective of active state.

    If `include_superusers` is `True` (default), the result will include superusers.

    If `backend` is passed in and it’s defined in `AUTHENTICATION_BACKENDS`, then this method will use it. Otherwise, it will use the `backend` in `AUTHENTICATION_BACKENDS`, if there is only one, or raise an exception.

## Objeto `AnonymousUser`

class `models.``AnonymousUser`

  `django.contrib.auth.models.AnonymousUser` is a class that implements the `django.contrib.auth.models.User` interface, with these differences:

  - id sempre é `None`.
  - `username` is always the empty string.
  - `get_username()` sempre retorna a string vazia.
  - `is_anonymous` é `True` ao invés de `False`.
  - `is_authenticated` is `False` ao invés de `True`.
  - `is_staff` e `is_superuser` são sempre `False`.
  - `is_active` são sempre `False`.
  - `groups` e `user_permissions` estão sempre vazios.
  - `set_password()`, `check_password()`, `save()` e `delete()` raise `NotImplementedError`.

In practice, you probably won’t need to use `AnonymousUser` objects on your own, but they’re used by Web requests, as explained in the next section.

## Modelo `Permission`

class `models.``Permission`

### Campos

`Permission` objects have the following fields:

class `models.``Permission`
  `name`

    Required. 255 characters or fewer. Example: `'Can vote'`.

  `content_type`

    Required. A reference to the `django_content_type` database table, which contains a record for each installed model.

  `codename`

    Required. 100 characters or fewer. Example: `'can_vote'`.

### Métodos

`Permission` objects have the standard data-access methods like any other Django model.

## Modelo``Group``

class `models.``Group`

### Campos

`Group` objects have the following fields:

class `models.``Group`
  `name`

    Required. 150 characters or fewer. Any characters are permitted. Example: `'Awesome Users'`.

  `permissions`

    Many-to-many field to `Permission`:

        group.permissions.set([permission_list])
        group.permissions.add(permission, permission, ...)
        group.permissions.remove(permission, permission, ...)
        group.permissions.clear()

## Validadores

class `validators.``ASCIIUsernameValidator`

  A field validator allowing only ASCII letters and numbers, in addition to `@`, `.`, `+`, `-`, and `_`.

class `validators.``UnicodeUsernameValidator`

  A field validator allowing Unicode characters, in addition to `@`, `.`, `+`, `-`, and `_`. The default validator for `User.username`.

## Login and logout signals

The auth framework uses the following signals that can be used for notification when a user logs in or out.

`user_logged_in`()

  Sent when a user logs in successfully.

  Arguments sent with this signal:

  `sender`
    The class of the user that just logged in.
  `request`
    The current `HttpRequest` instance.
  `user`
    The user instance that just logged in.

`user_logged_out`()

  Sent when the logout method is called.

  `sender`
    As above: the class of the user that just logged out or `None` if the user was not authenticated.
  `request`
    The current `HttpRequest` instance.
  `user`
    The user instance that just logged out or `None` if the user was not authenticated.

`user_login_failed`()

  Sent when the user failed to login successfully

  `sender`
    The name of the module used for authentication.
  `credentials`
    A dictionary of keyword arguments containing the user credentials that were passed to `authenticate()` or your own custom authentication backend. Credentials matching a set of ‘sensitive’ patterns, (including password) will not be sent in the clear as part of the signal.
  `request`
    The `HttpRequest` object, if one was provided to `authenticate()`.

## Authentication backends

This section details the authentication backends that come with Django. For information on how to use them and how to write your own authentication backends, see the Other authentication sources section of the User authentication guide.

### Available authentication backends

The following backends are available in `django.contrib.auth.backends`:

class `BaseBackend`
  New in Django 3.0.

  A base class that provides default implementations for all required methods. By default, it will reject any user and provide no permissions.

  `get_user_permissions`(user_obj, obj=None)

    Returns an empty set.

  `get_group_permissions`(user_obj, obj=None)

    Returns an empty set.

  `get_all_permissions`(user_obj, obj=None)

    Uses `get_user_permissions()` and `get_group_permissions()` to get the set of permission strings the `user_obj` has.

  `has_perm`(user_obj, perm, obj=None)

    Uses `get_all_permissions()` to check if `user_obj` has the permission string `perm`.

class `ModelBackend`

  This is the default authentication backend used by Django. It authenticates using credentials consisting of a user identifier and password. For Django’s default user model, the user identifier is the username, for custom user models it is the field specified by USERNAME_FIELD (see Customizing Users and authentication).

  It also handles the default permissions model as defined for `User` and `PermissionsMixin`.

  `has_perm()`, `get_all_permissions()`, `get_user_permissions()`, and `get_group_permissions()` allow an object to be passed as a parameter for object-specific permissions, but this backend does not implement them other than returning an empty set of permissions if `obj is not None`.

  `with_perm()` also allows an object to be passed as a parameter, but unlike others methods it returns an empty queryset if `obj is not None`.

  `authenticate`(request, username=None, password=None, **kwargs)

    Tries to authenticate `username` with `password` by calling `User.check_password`. If no `username` is provided, it tries to fetch a username from `kwargs` using the key `CustomUser.USERNAME_FIELD`. Returns an authenticated user or `None`.

    O `request` é uma `HttpRequest` e pode ser `None` se não foi fornecido para o `authenticate()` (o qual o passa para o backend).

  `get_user_permissions`(user_obj, obj=None)

    Returns the set of permission strings the `user_obj` has from their own user permissions. Returns an empty set if `is_anonymous` or `is_active` is `False`.

  `get_group_permissions`(user_obj, obj=None)

    Returns the set of permission strings the `user_obj` has from the permissions of the groups they belong. Returns an empty set if `is_anonymous` or `is_active` is `False`.

  `get_all_permissions`(user_obj, obj=None)

    Returns the set of permission strings the `user_obj` has, including both user permissions and group permissions. Returns an empty set if `is_anonymous` or `is_active` is `False`.

  `has_perm`(user_obj, perm, obj=None)

    Uses `get_all_permissions()` to check if `user_obj` has the permission string `perm`. Returns `False` if the user is not `is_active`.

  `has_module_perms`(user_obj, app_label)

    Returns whether the `user_obj` has any permissions on the app `app_label`.

  `user_can_authenticate`()

    Returns whether the user is allowed to authenticate. To match the behavior of `AuthenticationForm` which `prohibits inactive users from logging in`, this method returns `False` for users with `is_active=False`. Custom user models that don’t have an `is_active` field are allowed.

  `with_perm`(perm, is_active=True, include_superusers=True, obj=None)
    New in Django 3.0.

    Returns all active users who have the permission `perm` either in the form of `"<app label>.<permission codename>"` or a `Permission` instance. Returns an empty queryset if no users who have the `perm` found.

    If `is_active` is `True` (default), returns only active users, or if `False`, returns only inactive users. Use `None` to return all users irrespective of active state.

    If `include_superusers` is `True` (default), the result will include superusers.

class `AllowAllUsersModelBackend`

  Same as `ModelBackend` except that it doesn’t reject inactive users because `user_can_authenticate()` always returns `True`.

  When using this backend, you’ll likely want to customize the `AuthenticationForm` used by the `LoginView` by overriding the `confirm_login_allowed()` method as it rejects inactive users.

class `RemoteUserBackend`

  Use this backend to take advantage of external-to-Django-handled authentication. It authenticates using usernames passed in `request.META['REMOTE_USER']`. See the Authenticating against REMOTE_USER documentation.

  If you need more control, you can create your own authentication backend that inherits from this class and override these attributes or methods:

  `create_unknown_user`

    `True` or `False`. Determines whether or not a user object is created if not already in the database Defaults to `True`.

  `authenticate`(request, remote_user)

    The username passed as `remote_user` is considered trusted. This method returns the user object with the given username, creating a new user object if `create_unknown_user` is `True`.

    Returns `None` if `create_unknown_user` is `False` and a `User` object with the given username is not found in the database.

    O `request` é uma `HttpRequest` e pode ser `None` se não foi fornecido para o `authenticate()` (o qual o passa para o backend).

  `clean_username`(username)

    Performs any cleaning on the `username` (e.g. stripping LDAP DN information) prior to using it to get or create a user object. Returns the cleaned username.

  `configure_user`(request, user)

    Configures a newly created user. This method is called immediately after a new user is created, and can be used to perform custom setup actions, such as setting the user’s groups based on attributes in an LDAP directory. Returns the user object.

    O `request` é uma `HttpRequest` e pode ser `None` se não foi fornecido para o `authenticate()` (o qual o passa para o backend).

  `user_can_authenticate`()

    Returns whether the user is allowed to authenticate. This method returns `False` for users with `is_active=False`. Custom user models that don’t have an `is_active` field are allowed.

class `AllowAllUsersRemoteUserBackend`

  Same as `RemoteUserBackend` except that it doesn’t reject inactive users because `user_can_authenticate` always returns `True`.

## Utility functions

`get_user`(request)

  Returns the user model instance associated with the given `request`’s session.

  It checks if the authentication backend stored in the session is present in `AUTHENTICATION_BACKENDS`. If so, it uses the backend’s `get_user()` method to retrieve the user model instance and then verifies the session by calling the user model’s `get_session_auth_hash()` method.

  Returns an instance of `AnonymousUser` if the authentication backend stored in the session is no longer in `AUTHENTICATION_BACKENDS`, if a user isn’t returned by the backend’s `get_user()` method, or if the session auth hash doesn’t validate.