Creacion de UsuariosModelo Users AbstractBaseUser

usaremos AbstractBaseUser, PermissionsMixin

models.py

from django.db import models

from django.contrib.auth.models import AbstractBaseUser, PermissionsMixin
#
from .managers import UserManager

class User(AbstractBaseUser, PermissionsMixin):

    GENDER_CHOICES = (
        ('M', 'Masculino'),
        ('F', 'Femenino'),
        ('O', 'Otros'),
    )

    username = models.CharField(max_length=10, unique=True)
    email = models.EmailField()
    nombres = models.CharField(max_length=30, blank=True)
    apellidos = models.CharField(max_length=30, blank=True)
    genero = models.CharField(max_length=1, choices=GENDER_CHOICES, blank=True)
    codregistro = models.CharField(max_length=6, blank=True)
    #
    is_staff = models.BooleanField(default=False)
    is_active = models.BooleanField(default=False)

    USERNAME_FIELD = 'username'

    REQUIRED_FIELDS = ['email',]

    objects = UserManager()

    def get_short_name(self):
        return self.username
    
    def get_full_name(self):
        return self.nombres + ' ' + self.apellidos

se modifca el archivo base.py

from django.core.exceptions import ImproperlyConfigured
import json


# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
from unipath import Path
BASE_DIR = Path(__file__).ancestor(3)


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/2.2/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
with open("secret.json") as f:
    secret = json.loads(f.read())

def get_secret(secret_name, secrets=secret):
    try:
        return secrets[secret_name]
    except:
        msg = "la variable %s no existe" % secret_name
        raise ImproperlyConfigured(msg)



SECRET_KEY = get_secret('SECRET_KEY')


# Application definition

DJANGO_APPS = (
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
)

LOCAL_APPS = (
    'applications.users',
)

THIRD_PARTY_APPS = ()

INSTALLED_APPS = DJANGO_APPS + LOCAL_APPS + THIRD_PARTY_APPS

EMAIL_BACKEND = 'django.core.mail.backends.smtp.EmailBackend'

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

ROOT_URLCONF = 'usuarios.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [BASE_DIR.child('templates')],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'usuarios.wsgi.application'


# Password validation
# https://docs.djangoproject.com/en/2.2/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]

AUTH_USER_MODEL = 'users.User'  #constannte nueva para trabajar con este modelo de users

# Internationalization
# https://docs.djangoproject.com/en/2.2/topics/i18n/

LANGUAGE_CODE = 'es-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_L10N = True

USE_TZ = True

para trabjar con usuarios requiere necesariamente de los managers

managers.py

from django.db import models
#
from django.contrib.auth.models import BaseUserManager

class UserManager(BaseUserManager, models.Manager):

    def _create_user(self, username, email, password, is_staff, is_superuser, is_active, **extra_fields):
        user = self.model(
            username=username,
            email=email,
            is_staff=is_staff,
            is_superuser=is_superuser,
            is_active=is_active,
            **extra_fields
        )
        user.set_password(password)
        user.save(using=self.db)
        return user
    
    def create_user(self, username, email, password=None, **extra_fields):
        return self._create_user(username, email, password, False, False, False, **extra_fields)

    def create_superuser(self, username, email, password=None, **extra_fields):
        return self._create_user(username, email, password, True, True, True, **extra_fields)
    
    def cod_validation(self, id_user, cod_registro):
        if self.filter(id=id_user, codregistro=cod_registro).exists():
            return True
        else:
            return False