models.py

from django.contrib.auth.base_user import BaseUserManager, AbstractBaseUser
from django.contrib.auth.models import PermissionsMixin
from django.db import models
from django.utils import timezone
from django.utils.translation import gettext_lazy as _


class UserAccountManager(BaseUserManager):
    def _create_user(self, email, password, **extra_fields):
        email = self.normalize_email(email)
        user = self.model(email=email, **extra_fields)
        user.set_password(password)
        user.save()
        return user

    def create_user(self, email, password, **extra_fields):
        extra_fields.setdefault('is_staff', False)
        extra_fields.setdefault('is_superuser', False)
        extra_fields.setdefault('is_active', True)
        return self._create_user(email, password, **extra_fields)

    def create_staff_user(self, email, password, **extra_fields):
        extra_fields.setdefault('is_staff', True)
        extra_fields.setdefault('is_superuser', False)
        extra_fields.setdefault('is_active', True)
        return self._create_user(email, password, **extra_fields)

    def create_superuser(self, email, password, **extra_fields):
        extra_fields.setdefault('is_staff', True)
        extra_fields.setdefault('is_superuser', True)
        extra_fields.setdefault('is_active', True)
        return self._create_user(email, password, **extra_fields)


class User(AbstractBaseUser, PermissionsMixin):
    first_name = models.CharField(_('First name'), max_length=30, blank=True)
    last_name = models.CharField(_('Last name'), max_length=30, blank=True)
    email = models.EmailField(_('Email address'), unique=True)
    is_staff = models.BooleanField(_('staff status'), default=False,
                                   help_text=_('Designates whether the user can log into this admin site.'), )
    is_active = models.BooleanField(_('active'), default=False, help_text=_(
        'Designates whether this user should be treated as active.'), )
    date_joined = models.DateTimeField(_('Date joined'), default=timezone.now)

    objects = UserAccountManager()
    USERNAME_FIELD = 'email'
    REQUIRED_FIELDS = ['first_name', 'last_name']

    class Meta:
        verbose_name = _('User')
        verbose_name_plural = _('User')
        ordering = ('-pk',)

    def __str__(self):
        return self.email

    def get_full_name(self):
        """
        Returns the first_name plus the last_name, with a space in between.
        """
        full_name = "{} {}".format(self.first_name, self.last_name)
        return full_name.strip()

    def get_short_name(self):
        return self.first_name.strip()

admin.py

from django.contrib import admin
from django.contrib.auth.admin import UserAdmin
from django.utils.translation import gettext_lazy as _

from .models import User


class CustomUserAdmin(UserAdmin):
    list_display = ('email', 'first_name', 'last_name', 'is_staff')
    ordering = ('date_joined',)

    fieldsets = (
        (None, {'fields': ('email', 'password')}),
        (_('Personal info'), {'fields': ('first_name', 'last_name')}),
        (_('Permissions'), {'fields': ('is_active', 'is_staff', 'is_superuser', 'groups', 'user_permissions')}),
        (_('Important dates'), {'fields': ('last_login', 'date_joined')}),
    )
    add_fieldsets = (
        (None, {
            'classes': ('wide',),
            'fields': ('email', 'password1', 'password2'),
        }),
    )
    list_filter = ('is_staff', 'is_superuser', 'is_active', 'groups')
    search_fields = ('email', 'first_name', 'last_name', 'email')


admin.site.register(User, CustomUserAdmin)