TypeError: NoneType object is not subscriptable 方案解决
运行FLASK_APP=app.pyFLASK_DEBUG=trueflaskrun出现了报错。'''在app_v3.py的版本上进行改变'''fromflaskimportFlask,render_template,request,redirect,url_for,jsonifyfromflask_sqlalchemyimportSQLAlchemy#原本报错,以下来自stackoverflow