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 modelclass 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.
Usernames and Unicode
Django originally accepted only ASCII letters and numbers in usernames. Although it wasn’t a deliberate choice, Unicode characters have always been accepted when using Python 3. Django 1.10 officially added Unicode support in usernames, keeping the ASCII-only behavior on Python 2.
The max_length increased from 30 to 150 characters.
first_name Optional (blank=True). 30 characters or fewer.
last_name Optional (blank=True). 30 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.
In older versions, ModelBackend and RemoteUserBackend allowed inactive users to authenticate.
is_superuser Boolean. Designates that this user has all permissions without explicitly assigning them.
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.
class models.User is_authenticated Read-only attribute which is always True (as opposed to AnonymousUser.is_authenticated which is always False). This is a way to tell if the user has been authenticated. This does not imply any permissions and doesn’t check if the user is active or has a valid session. Even though normally you will check this attribute on request.user to find out whether it has been populated by the AuthenticationMiddleware (representing the currently logged-in user), you should know this attribute is True for any User instance.
In older versions, this was a method. Backwards-compatibility support for using it as a method will be removed in Django 2.0.
Don’t use the is operator for comparisons!
To allow the is_authenticated and is_anonymous attributes to also work as methods, the attributes are CallableBool objects. Thus, until the deprecation period ends in Django 2.0, you can’t compare these properties using the is operator. That is, request.user.is_authenticated is True always evaluate to False.
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.
In older versions, this was a method. Backwards-compatibility support for using it as a method will be removed in Django 2.0.
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() Returns the 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) Returns True if the given raw string is the correct password for the user. (This takes care of the password hashing in making the comparison.)
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.
You may need this if authentication for your application takes place against an existing external source such as an LDAP directory.
has_usable_password() Returns False if set_unusable_password() has been called for this user.
get_group_permissions(obj=None) Returns a set of permission strings that the user has, through their groups.
If obj is passed in, only returns the group permissions for this specific object.
get_all_permissions(obj=None) Returns a set of permission strings that the user has, both through group and user permissions.
If obj is passed in, only returns the permissions for this specific object.
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.
If obj is passed in, this method won’t check for a permission for the model, but for this specific object.
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.
If obj is passed in, this method won’t check for permissions for the model, but for the specific object.
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.
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.
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, password, **extra_fields) Same as create_user(), but sets is_staff and is_superuser to True.
AnonymousUser objectclass models.AnonymousUser django.contrib.auth.models.AnonymousUser is a class that implements the django.contrib.auth.models.User interface, with these differences:
None.username is always the empty string.get_username() always returns the empty string.is_anonymous is True instead of False.is_authenticated is False instead of True.is_staff and is_superuser are always False.is_active is always False.groups and user_permissions are always empty.set_password(), check_password(), save() and 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.
Permission modelclass models.Permission 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'.
Permission objects have the standard data-access methods like any other Django model.
Group modelclass models.Group Group objects have the following fields:
class models.Group name Required. 80 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()
class validators.ASCIIUsernameValidator A field validator allowing only ASCII letters and numbers, in addition to @, ., +, -, and _. The default validator for User.username on Python 2.
class validators.UnicodeUsernameValidator A field validator allowing Unicode characters, in addition to @, ., +, -, and _. The default validator for User.username on Python 3.
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 request HttpRequest instance.user user_logged_out() Sent when the logout method is called.
sender None if the user was not authenticated.request HttpRequest instance.user None if the user was not authenticated.user_login_failed() Sent when the user failed to login successfully
sender credentials 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 HttpRequest object, if one was provided to authenticate().The request argument was added.
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.
The following backends are available in django.contrib.auth.backends:
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.
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.
request is an HttpRequest and may be None if it wasn’t provided to authenticate() (which passes it on to the backend).
The request argument was added.
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.
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:
RemoteUserBackend.create_unknown_user True or False. Determines whether or not a user object is created if not already in the database Defaults to True.
RemoteUserBackend.authenticate(request, remote_user) The username passed as remote_user is considered trusted. This method simply 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.
request is an HttpRequest and may be None if it wasn’t provided to authenticate() (which passes it on to the backend).
RemoteUserBackend.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.
RemoteUserBackend.configure_user(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.
RemoteUserBackend.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.
get_user(request) [source]
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.
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Licensed under the BSD License.
https://docs.djangoproject.com/en/1.11/ref/contrib/auth/