User model for Django with an email/password login, no username

models.py

from django.db import models
from django.core.mail import send_mail
from django.contrib import auth
from django.contrib.auth.models import (
    AbstractBaseUser,
    BaseUserManager,
    Group,
    Permission,
    _user_get_all_permissions,
    _user_has_perm,
    _user_has_module_perms,
)
from django.utils.translation import ugettext_lazy as _
from django.utils import timezone


class UserManager(BaseUserManager):
    def create_user(self, email, password=None, **kw):
        """
        Creates a user with a given email address and password
        """
        if not email:
            raise ValueError('The given email address must be set')

        u = self.model(
            email=UserManager.normalize_email(email),
            **kw
        )
        u.set_password(password)
        u.save(using=self._db)
        return u

    def create_superuser(self, email, password, **kw):
        """
        Creates a superuser with a given email address and password
        """
        u = self.create_user(email, password, **kw)
        u.is_staff = True
        u.is_active = True
        u.is_superuser = True
        u.save(using=self._db)
        return u


class User(AbstractBaseUser):
    """
    Model for users across the site
    """
    email = models.EmailField(_('email_address'), max_length=255, unique=True)
    first_name = models.CharField(_('first name'), max_length=30, blank=True)
    last_name = models.CharField(_('last name'), max_length=30, blank=True)
    is_active = models.BooleanField(
        _('active'),
        default=True,
        help_text=_('Disable this instead of deleting a user')
    )
    is_staff = models.BooleanField(
        _('staff status'),
        default=False,
        help_text=_('Allow the user access to the admin site')
    )
    is_superuser = models.BooleanField(
        _('superuser status'),
        default=False,
        help_text=_('User has all permissions')
    )
    date_joined = models.DateTimeField(_('date joined'), default=timezone.now)
    groups = models.ManyToManyField(
        Group,
        verbose_name=_('groups'),
        blank=True,
        help_text=_('Groups a user belongs to and inherits permissions from')
    )
    user_permissions = models.ManyToManyField(
        Permission,
        verbose_name=_('user permissions'),
        blank=True,
        help_text=_('Permissions for this user')
    )

    objects = UserManager()

    USERNAME_FIELD = 'email'

    class Meta:
        verbose_name = _('user')
        verbose_name_plural = _('users')

    def get_full_name(self):
        """
        Return the first name and last name
        """
        full_name = '%s %s' % (self.first_name, self.last_name)
        return full_name.strip()

    def get_short_name(self):
        """
        Since the user is identified by their email address return that
        """
        return self.email

    def get_group_permissions(self, obj=None):
        """
        Returns a list of permissions that this user has through their groups
        """
        permissions = set()
        for backend in auth.get_backends():
            if hasattr(backend, 'get_group_permissions'):
                if obj is not None:
                    permissions.update(backend.get_group_permissions(
                        self, obj
                    ))
                else:
                    permissions.update(backend.get_group_permissions(self))
        return permissions

    def get_all_permissions(self, obj=None):
        return _user_get_all_permissions(self, obj)

    def has_perm(self, perm, obj=None):
        """
        Returns True if the user has the given permission
        """
        if self.is_active and self.is_superuser:
            return True

        return _user_has_perm(self, perm, obj)

    def has_perms(self, perm_list, obj=None):
        """
        Returns True if the user has each of the permissions in the give list
        """
        for perm in perm_list:
            if not self.has_perm(perm, obj):
                return False
        return True

    def has_module_perms(self, app_label):
        """
        Returns True if the user has any permissions in the give app label
        """
        if self.is_active and self.is_superuser:
            return True

        return _user_has_module_perms(self, app_label)

    def email_user(self, subject, message, from_email=None):
        """
        Sends an email to the user
        """
        send_mail(subject, message, from_email, [self.email])