登陆需要账号密码，之前只写了账号，现在把密码加进去，修改models.py:

from . import db

class User(db.Model):
    __tablename__ = 'users'
    id = db.Column(db.Integer, primary_key=True)
    # 如果你学过数据库的话就知道我们一般通过id来作为主键，来找到对应的信息的,通过id来实现唯一性

    username = db.Column(db.String(64), unique=True)
    password = db.Column(db.String(64))

    def __repr__(self):
        return 'users表: id为:{}, name为:{}'.format(self.id, self.username)

只有在密码和账号都输入了的情况下，才返回数据，否则不返回，修改路由：

@main.route('/register', methods=['POST'])
def register():
    username = request.form['username']
    password = request.form['password']

    if username and password:
        user = User.query.filter_by(username=username)
        if user is None:
            ##添加进数据库
            user = User(username=username)
            ##如果没有app.config['SQLALCHEMY_COMMIT_TEARDOWN'] = True
            ##这句后面还要加上db.session.commit()才会提交到数据库
            db.session.add(user)
            session['known'] = False
        else:
            session['known'] = True

        session['username'] = username
        session['password'] = password

        username=session.get('username')
        password = session.get('password')
        return json.dumps({
            'username': username,
            'password': password
        })
    else:
        return '请输入正确的账号密码'

return Json.dumps 返回了一个json数据，记得import json

教程下一步是判断用户是否登陆（选择进入登陆页还是主页），这里我把这个判断放到前端，前端传给后台用户名和密码，后台给一个token，前端保存token，用户退出则清除token

基于token的用户认证

• 添加生成token和验证token的方法，models.py:

    from itsdangerous import TimedJSONWebSignatureSerializer as Serializer

    def generate_auth_token(self, expiration = 600):
        s = Serializer(app.config['SECRET_KEY'], expires_in = expiration)
        return s.dumps({ 'id': self.id })

    @staticmethod
    def verify_auth_token(token):
        s = Serializer(app.config['SECRET_KEY'])
        try:
            data = s.loads(token)
        except SignatureExpired:
            return None # valid token, but expired
        except BadSignature:
            return None # invalid token
        user = User.query.get(data['id'])
        return user