初始化数据库时出现错误

进行初始化数据库是flask db init
出现

以下是init.py的代码
from flask import Flask,render_template
from flask_bootstrap import Bootstrap
from flask_login.utils import login_fresh
from flask_mail import Mailfrom flask_moment import Moment
from flask_sqlalchemy import SQLAlchemy
from config import config
from flask_login import LoginManager, login_manager
bootstrap = Bootstrap()
mail = Mail()
moment = Moment()
db = SQLAlchemy()

login_manager=LoginManager()
login_manager.login_view='auth.login'
def create_app(config_name):
app = Flask(name)
app.config.from_object(config[config_
name])
config[config_name].init_app(app)
bootstrap.init_app(app)
mail.init_app(app)
moment.init_app(app)
login_manager.init_app(app)
db.init_app(app)
# 添加路由和自定义的错误页面
from app.auth import auth as auth_blue
print
app.register_blueprint(auth_blueprint, u
rl_prefix='/auth')
from app.main import main as main_bl
ueprint
app.register_blueprint(main_blueprint)
return app