Flask-SQLAlchemy错误

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask import Response
from flask import json, jsonify

app = Flask(__name__)
app.config[‘SQLALCHEMY_DATABASE_URI‘] = ‘mysql+pymysql://root:123456@localhost/TestBlog‘
app.config[‘SQLALCHEMY_TRACK_MODIFICATIONS‘] = True
db = SQLAlchemy(app)

class User(db.Model):
    __tablename__ = ‘t_users‘
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True)
    password = db.Column(db.String(100))
    email = db.Column(db.String(120), unique=True)

    def __init__(self, username, password, email):
        self.username = username
        self.password = password
        self.email = email

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


@app.route(‘/‘)
def hello_world():
    # me = User(‘zxj‘)
    # db.session.add(me)
    return ‘{"name":"zxj"}‘

@app.route(‘/register‘, methods = [‘POST‘])
def register():
    data = {
        ‘username‘: ‘张先生‘,
        ‘userID‘: 1
    }
    # js = json.dumps(data)
    # resp = Response(js, status=200, mimetype=‘application/json‘)
    udata = User(‘admin‘,‘password‘,‘admin@admin.com‘)
    db.session.add(udata)
    db.session.commit()
    return jsonify(data)

if __name__ == ‘__main__‘:
    app.run()