关于flask登录视图报错AttributeError: ‘_AppCtxGlobals’ object has no attribute ‘user’详解大数据

@app.route('/login',methods = ['GET','POST']) 
@oid.loginhandler 
def login(): 
    if g.user is not None and g.user.is_authenticated: 
        return redirect(url_for('index')) 
    form = LoginForm() 
    if form.validate_on_submit(): 
        session['remember_me'] = form.remember_me.data 
        return oid.try_login(form.openid.data,ask_for=['nickname','email']) 
    return  render_template('login.html', 
                            title = 'Sign In', 
                            form = form, 
                            providers = app.config['OPENID_PROVIDERS'])

@app.before_request 
def before_request(): 
    g.user = current_user