python-pylint'C0103：无效的常量名称

我对这张照片中的错误感到困惑：

我不知道该如何解决。我的程序是Python-Flask网络框架。当我使用VScode调试程序时，Pylint显示这些错误。我知道这个问题无关紧要，但这让我很烦。我该如何解决？

# -*- coding: utf-8 -*-
import sys
from flask import Flask
from flask_bootstrap import Bootstrap
from flask_moment import Moment
#from flask_wtf import Form
#from wtforms import StringField, SubmitField
#from wtforms.validators import Required
from flask_sqlalchemy import SQLAlchemy

reload(sys)
sys.setdefaultencoding('utf-8')

app = Flask(__name__)
app.config['SECRET_KEY'] = 'hard to guess string'
app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://root:@localhost:3306/test?'
app.config['SQLALCHEMY_COMMIT_ON_TEARDOWN'] = True
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = True

bootstrap = Bootstrap(app)
moment = Moment(app)
db = SQLAlchemy(app)


if __name__ == '__main__':
    db.create_all()
    app.run()