我试图在django中创建一个自定义用户模型。我得到的错误是
如果不是isinstance（cls.required_字段，（列表，元组））：attributeerror:type对象“customuser”没有属性“required_字段”
我在settings.py中添加了我的customuser模型，如下所示。

AUTH_USER_MODEL = "Pollapp.CustomUser"

这是我的model.py

from django.contrib.auth.models import BaseUserManager, PermissionsMixin
from django.contrib.auth.base_user import AbstractBaseUser
class UserManager(BaseUserManager):
    def create_user(self, email, firstname, lastname, phone,password=None):
        user = self.model(
            email = self.normalize_email(email),
            firstname = firstname,
            lastname = lastname,
            phone = phone,
        )
        user.set_password(password)
        user.save(using = self._db)
        return user
    def create_superuser(self, email,firstname,lastname,phone,password=None):
        user = self.create_user(
            email=email,
            password=password,
            firstname = firstname,
            lastname = lastname,
            phone = phone,
        )
        user.is_admin = True
        user.is_staff = True
        user.save(using=self._db)
        return user
class CustomUser(AbstractBaseUser, PermissionsMixin):
    id = models.CharField(max_length=200, default=uuid.uuid4,unique=True,primary_key=True)
    email = models.EmailField(null=False, max_length=100,unique=True)
    firstname = models.CharField(null=False, max_length=100)
    lastname = models.CharField(null=False, max_length=100)
    phone = models.IntegerField(null=False,unique=True)
    date_joined = models.DateTimeField(auto_now=True)
    last_login = models.DateTimeField(auto_now=True)
    is_admin = models.BooleanField(default = False)
    is_active = models.BooleanField(default = True)
    is_staff = models.BooleanField(default = False)
    is_superuser = models.BooleanField(default = False)
    USERNAME_FIELD = 'email'
    REQUIRED_FIELDS = ['firstname','lastname','phone']
    objects = UserManager()
    def __str__(self):
        return self.email + ", " + self.firstname
    def has_perm(self, perm, obj = None):
        return self.is_admin
    def has_module_perms(self, app_label):
        return True

我还尝试提供必需的字段，如必需的字段=（'firstname'、'lastname'、'phone'）
这是我的serializers.py

class UserSerializer(serializers.ModelSerializer):
    class Meta:
        model = CustomUser
        fields = ('__all__')
class UserSerializerWithToken(serializers.ModelSerializer):
    token = serializers.SerializerMethodField()
    password = serializers.CharField(write_only=True)
    def get_token(self, obj):
        jwt_payload_handler = api_settings.JWT_PAYLOAD_HANDLER
        jwt_encode_handler = api_settings.JWT_ENCODE_HANDLER
        payload = jwt_payload_handler(obj)
        token = jwt_encode_handler(payload)
        return token
    def create(self, validated_data):
        password = validated_data.pop('password', None)
        instance = self.Meta.model(**validated_data)
        if password is not None:
            instance.set_password(password)
        instance.save()
        return instance
    class Meta:
        model = CustomUser
        fields = ('token', 'username', 'password')
class RegisterSerializer(serializers.ModelSerializer):
    password = serializers.CharField(write_only=True, required=True, validators=[validate_password])
    password2 = serializers.CharField(write_only=True, required=True)
    class Meta:
        model = CustomUser
        fields = ('username', 'password', 'password2', 'email', 'first_name', 'last_name')
    def validate(self, attrs):
        if attrs['password'] != attrs['password2']:
            raise serializers.ValidationError({"password": "Password fields didn't match."})
        return attrs
    def create(self, validated_data):
        user = User.objects.create(
            username=validated_data['username'],
            email=validated_data['email'],
            first_name=validated_data['first_name'],
            last_name=validated_data['last_name'],
        )
        user.set_password(validated_data['password'])
        user.save()
        return user