如何过滤烧瓶棉花糖嵌套字段？

Question

我在用户的面向公众个人资料页面上工作，我想在其中显示用户的个人资料以及他们“已发布”的食谱。我有以下 UserSchema，但此架构显示所有配方，包括尚未发布的配方。我只想严格显示已发布的食谱。有没有办法过滤掉尚未发布的食谱？我查看了棉花糖文档，但找不到答案。

class User(db.Model):
     __tablename__ = 'user'

     id = db.Column(db.Integer, primary_key=True)
     username = db.Column(db.String(80), nullable=False, unique=True)
     email = db.Column(db.String(200), nullable=False, unique=True)
     password = db.Column(db.String(200))
     recipes = db.relationship('Recipe', backref='user')

class UserSchema(Schema):
      class Meta:
           ordered = True

      id = fields.Int(dump_only=True)
      username = fields.String(required=True)
      email = fields.Email(required=True)
      password = fields.Method(required=True)
      recipes = fields.Nested("RecipeSchema", many=True, exclude=("author",))

以下是 RecipeModel 和 RecipeSchema，

class Recipe(db.Model):
      __tablename__ = 'recipe'

      id = db.Column(db.Integer, primary_key=True)
      name = db.Column(db.String(100), nullable=False)
      description = db.Column(db.String(200))
      is_publish = db.Column(db.Boolean(), default=False)
      user_id = db.Column(db.Integer(), db.ForeignKey("user.id"))

class RecipeSchema(Schema):
      class Meta:
            ordered = True

       id = fields.Integer(dump_only=True)
       name = fields.String(required=True, validate=[validate.Length(max=100)])
       description = fields.String(validate=[validate.Length(max=200)])           
       is_publish = fields.Boolean(dump_only=True)     
       author = fields.Nested(UserSchema, attribute='user', dump_only=True, exclude=('email', ))

负责返回用户配置文件数据的资源是：

from schemas.user import UserSchema
user_schema =  UserSchema()
class UserResource(Resource):
      @classmethod
      def get(cls, _id: int):
            user = User.query.filter_by(id=_id).first()    
            if not user:
                 return {"message": gettext("user_not_found")}, 404
            return user_schema.dump(user), 200

当前输出为

{
    "id": "1",
    "username": "john.doe",    
    "recipes": [
        {
            "id": "1",
            "name": "cheese pizza",
            "description": "yummy",           
            "is_publish": true
        },
        {
            "id": "2",
            "name": "Potato Salad",
            "description": "tags with sepearate function",           
            "is_publish": false
        }
    ]
}

我想要它

{
    "id": "1",
    "username": "john.doe",    
    "recipes": [
        {
            "id": "1",
            "name": "cheese pizza",
            "description": "yummy",           
            "is_publish": true
        }
    ]
}