AbstractUser vs AbstractBaseUser

The default user model in Django uses a username to uniquely identify a user during authentication. If you'd rather use an email address, you'll need to create a custom user model by either subclassing AbstractUser or AbstractBaseUser.

Options:

1. AbstractUser: Use this option if you are happy with the existing fields on the user model and just want to remove the username field.
2. AbstractBaseUser: Use this option if you want to start from scratch by creating your own, completely new user model.

The steps are the same for each:

1. Create a custom user model and Manager
2. Update settings.py
3. Customize the UserCreationForm and UserChangeForm forms
4. Update the admin

Model Manager

First, we need to add a custom Manager, by subclassing BaseUserManager, that uses an email as the unique identifier instead of a username.

Create a managers.py file in the "users" directory:

from django.contrib.auth.base_user import BaseUserManager
from django.utils.translation import gettext_lazy as _

class CustomUserManager(BaseUserManager):
    """
    Custom user model manager where email is the unique identifiers
    for authentication instead of usernames.
    """
    def create_user(self, email, password, **extra_fields):
        """
        Create and save a user with the given email and password.
        """
        if not email:
            raise ValueError(_("The Email must be set"))
        email = self.normalize_email(email)
        user = self.model(email=email, **extra_fields)
        user.set_password(password)
        user.save()
        return user

    def create_superuser(self, email, password, **extra_fields):
        """
        Create and save a SuperUser with the given email and password.
        """
        extra_fields.setdefault("is_staff", True)
        extra_fields.setdefault("is_superuser", True)
        extra_fields.setdefault("is_active", True)

        if extra_fields.get("is_staff") is not True:
            raise ValueError(_("Superuser must have is_staff=True."))
        if extra_fields.get("is_superuser") is not True:
            raise ValueError(_("Superuser must have is_superuser=True."))
        return self.create_user(email, password, **extra_fields)

AbstractUser

Update users/models.py:

from django.contrib.auth.models import AbstractUser
from django.db import models
from django.utils.translation import gettext_lazy as _

from .managers import CustomUserManager

class CustomUser(AbstractUser):
    username = None
    email = models.EmailField(_("email address"), unique=True)

    USERNAME_FIELD = "email"
    REQUIRED_FIELDS = []

    objects = CustomUserManager()

    def __str__(self):
        return self.email