获取 cursor.close() UnboundLocalError：调用 /api/view/addmin 时在赋值错误之前引用了局部变量“cursor”

如何解决获取 cursor.close() UnboundLocalError：调用 /api/view/addmin 时在赋值错误之前引用了局部变量“cursor”

这是我遇到错误的代码。使用 sqlAlchemy 实现了相同的操作，但是当我在 MysqL 中编写它时，我遇到了错误。

    import pyMysqL
    from functools import  wraps
    import jwt
    import uuid
    import  datetime
    from werkzeug.security import generate_password_hash,check_password_hash
    from app import app
    from config import MysqL
    from flask import jsonify
    from flask import flash,request
    app.config['SECRET_KEY']='confidential'
    
    def token_required(f):
        @wraps(f)
        def decorated(*args,**kwargs):
            token= None
            if 'x-acess-token' in request.headers:
                token=request.headers['x-acess-token']
            if not  token:
                return  jsonify("token not found")
            try:
                data=jwt.decode(token,app.config['SECRET_KEY'])
                conn=MysqL.connect()
                cursor=conn.cursor(pyMysqL.cursors.DictCursor)
                cursor.execute('select  * from hireme_emp  where id=%s',data['id'])
                current_user=cursor.fetchone()
            except:
                return jsonify('invalid token')
            finally:
                cursor.close()
                conn.close()
            return  f(current_user,*args,**kwargs)
        return decorated

#-----------------------------------------------

    app.route('/api/view/addmin')
    @token_required
    def view_addmin(current_user):
        try:
            conn=MysqL.connect()
            cursor=conn.cursor(pyMysqL.cursors.DictCursor)
            cursor.execute("SELECT * FROM hireme_emp WHERE admin=1")
            rows=cursor.fetchall()
            resp=jsonify(rows)
            resp.status_code=200
            return  resp
        except Exception as e:
            print(e)
        finally:
            cursor.close()
            conn.close()

这是我在没有令牌的情况下运行此端点时的代码，然后它给出“未找到令牌”消息，但是当我发送令牌时，它显示此错误，即（

ERROR :line 30,in decorated
    cursor.close()
UnboundLocalError: local variable 'cursor' referenced before assignment
127.0.0.1 - - [23/Jul/2021 01:08:53] "GET /api/view/addmin HTTP/1.1" 500 -. 

实际上下面的代码使用 sqlAlchemy 执行相同的工作并且正在工作。我只是想用纯 MysqL 重写这段代码，但我不明白我哪里出错了。预先感谢您的帮助

def token_required(f):
    @wraps(f)
    def decorated(*args,**kwargs):
        token = None

        if 'x-access-token' in request.headers:
            token = request.headers['x-access-token']

        if not token:
            return jsonify({'message' : 'Token is missing!'}),401

        try: 
            data = jwt.decode(token,app.config['SECRET_KEY'])
            current_user = User.query.filter_by(public_id=data['public_id']).first()
        except:
            return jsonify({'message' : 'Token is invalid!'}),401

        return f(current_user,**kwargs)

    return decorated

解决方法

在开始 try catch 之前定义 conn 和 cursor

进一步您的工作代码显示您使用的是 public_id 而不是 id

我还将代码 cursor.execute 更改为元组

def token_required(f):
    @wraps(f)
    def decorated(*args,**kwargs):
        token= None
        if 'x-acess-token' in request.headers:
            token=request.headers['x-acess-token']
        if not  token:
            return  jsonify("token not found")
            
        conn=mysql.connect()
        cursor=conn.cursor(pymysql.cursors.DictCursor)
        try:
            data=jwt.decode(token,app.config['SECRET_KEY'])
            cursor.execute('select  * from hireme_emp  where id=%s LIMIT 1',(data['public_id'],))
            current_user=cursor.fetchone()
        except:
            return jsonify('invalid token')
        finally:
            cursor.close()
            conn.close()
        return  f(current_user,*args,**kwargs)
    return decorated