class UserManager(BaseUserManager):
def create_user(self, phone, password=None):
    if not phone:
        raise ValueError('Please, enter the correct phone number')

    user = self.model(phone=phone)
    user.set_password(password)
    user.save(using=self._db)
    return user

def create_superuser(self, phone, password):
    user = self.create_user(phone=phone, password=password)
    user.is_admin = True
    user.is_staff = True
    user.is_superuser = True
    user.save(using=self._db)
    return user


class User(AbstractBaseUser, PermissionsMixin):
    phone_regex = RegexValidator(regex=r'^+?1?d{9,15}$', message="Phone number   must be entered in the format: '+999999999'. Up to 15 digits allowed.")
    phone = models.CharField(validators=[phone_regex], blank=True, max_length=15)
    phone = models.IntegerField(('contact number'), unique=True, db_index=True)
  # email = models.EmailField(_('email address'), unique=True)
    is_admin = models.BooleanField('superuser', default=False)
    is_staff = models.BooleanField(default=False)

objects = UserManager()

USERNAME_FIELD = 'phone'

def get_full_name(self):
    return str(self.phone)

def get_short_name(self):
    return str(self.phone)

def __unicode__(self):
    return str(self.phone)