類型錯誤：在0x7f86789f9bf8 sqlalchemy.orm.attributes.InstrumentedAttribute對象不是JSON序列化

Question

我使用燒瓶瓶，登錄用戶認證。燒瓶SQLAlchemy中存儲這些車型在SQLite數據庫：

ROLE_USER = 0 
ROLE_ADMIN = 1 

class Anonymous(AnonymousUserMixin): 
    def __init__(self): 
    self.username = 'Guest' 

lm.anonymous_user = Anonymous 

class User(UserMixin, db.Model): 
__tablename__ = "users" 
id = db.Column(db.Integer, primary_key = True) 
username = db.Column(db.String(64), index = True, unique = True) 
password = db.Column(db.String(20), index = False, unique = True) 
email = db.Column(db.String(120), index = True, unique = True) 
registered_on = db.Column('registered_on' , db.DateTime) 
role = db.Column(db.SmallInteger, default = ROLE_USER) 

def __repr__(self): 
    return '<User %r>' % (self.username) 

def get_id(self): 
    return User.id 


class PostVote(db.Model): 
__tablename__ = "postvotes" 
post_id = db.Column(db.Integer, db.ForeignKey('posts.id'), primary_key = True) 
user_id = db.Column(db.Integer, default = 0) 
type = db.Column(db.Boolean, default = True) 

class Post(db.Model): 
__tablename__ = "posts" 
id = db.Column(db.Integer, primary_key = True) 
body = db.Column(db.String(320)) 
points = db.Column(db.Integer, default = 0) 
votes = db.relationship(PostVote) 
timestamp = db.Column(db.DateTime) 
user_id = db.Column(db.Integer, db.ForeignKey('users.id')) 

def __repr__(self): 
    return '<Post %r>' % self.body 

我的登錄代碼：

@app.route('/login', methods = ['GET', 'POST']) 
def init_login(): 
form = LoginForm() 
if request.method == 'GET': 
    return render_template('login/index.html', form = form, active = 'login') 
if form.validate(): 
    uname = form.username.data 
    passw = form.password.data 
    print('DBG: Loginning ' + uname) #for debug purposes 
    registered_user = User.query.filter_by(username = uname).first() 
    if registered_user is None: 
     flash('User not found') 
     return render_template('/login/index.html', form=form, 
     msgtype = 'alert-warning', active = 'login') 
    if check_passw(passw, registered_user.password): 
     login_user(registered_user) 
     session['username'] = uname 
     return redirect(url_for('init_login_success')) 
    else: 
     flash('Incorrect password') 
     return render_template('/login/index.html', form=form, 
     msgtype = 'alert-danger', active = 'login') 
return render_template('login/index.html', form = form, active = 'login') 

當我試圖登錄，SQLAlchemy的觸發錯誤，您可以在文章標題（TypeError: <sqlalchemy.orm.attributes.InstrumentedAttribute object at 0x7f86789f9bf8> is not JSON serializable）見。 AFAIK，InstumentedAttribute用於關係，但它沒有幫助我。
我還發現發生該錯誤則（）執行login_user。登錄無需登錄即可正常工作。
我怎樣才能解決這個問題？

Answer 1

眼下get_id()在文檔同時返回一個整數：

get_id()
This method must return a unicode that uniquely identifies this user, and can be used to load the user from the user_loader callback. Note that this must be a unicode - if the ID is natively an int or some other type, you will need to convert it to unicode.

我寫了這個要解決的問題：

def get_id(self): 
     return str(self.id)