What is the purpose of the UserManager class in django?

Question

What is the purpose of the UserManager class in django?

The documentation doesn't seem to really explain what it is for.

Answer 1

The main purpose is to create (super)users. Since passwords are hashed, that is not simply achivable with a .create(…) ^[Django-doc].

The UserManager ^[Django-doc] is thus a Manager, with extra methods:

• .create_user(…) ^[Django-doc] to create a user;
• .create_superuser(…) ^[Django-doc] to create a user that is a superuser; and
• with_perm(…) ^[Django-doc] that returns a set of User objects that have a given permission.

If we take a look at the standard UserManager implementation ^[GitHub], we see:

    def _create_user(self, username, email, password, **extra_fields):
        """
        Create and save a user with the given username, email, and password.
        """
        if not username:
            raise ValueError('The given username must be set')
        email = self.normalize_email(email)
        username = self.model.normalize_username(username)
        user = self.model(username=username, email=email, **extra_fields)
        user.set_password(password)
        user.save(using=self._db)
        return user

    def create_user(self, username, email=None, password=None, **extra_fields):
        extra_fields.setdefault('is_staff', False)
        extra_fields.setdefault('is_superuser', False)
        return self._create_user(username, email, password, **extra_fields)

It will thus normalize both the username and email address, and furthermore use the .set_password(…) method ^[Django-doc] to set the password, to ensure that the password is hashed before saving it to the database.