python中登录、注册操作数据库

# 1、注册、登录
# 1、注册的时候存账户密码到数据库里面，密码存密文，要加盐
# 2、登录的时候账号、密码从数据里面取，登录失败一次，错误次数 + 1，错误次数大于3不让登录
# 1、建表  id,username,password,error_count
# 2、账号不存在，并且2次输入的密码是一致，就插入到数据库里面
# select * from nhy_user where username='%s' % username


# 1、账号密码
# 2、select password,error_count from nhy_user where username = '%s' % username
# 3、取到error_count，判断是否大于3
# 4、把用户输入的密码MD5一下，和数据库里面存的密码对比

import pymysql, hashlib


def op_mysql(sql: str):
    mysql_info = {
        'host': '***.24.3.40',
        'port': 3306,
        'password': '***',
        'user': 'jxz',
        'db': 'jxz',
        'charset': 'utf8',
        'autocommit': True
    }
    result = '执行完成'
    conn = pymysql.connect(**mysql_info)
    cur = conn.cursor(pymysql.cursors.DictCursor)  # 建立游标
    cur.execute(sql)
    if sql.strip().lower().startswith('select'):
        result = cur.fetchone()
        # result  = cur.fetchall()
    cur.close()
    conn.close()
    return result


def md5(s, salt='$!@#$12232'):
    s = (str(s) + salt).encode()
    m = hashlib.md5(s)  # 加密
    return m.hexdigest()


def register():
    for i in range(3):
        username = input('username:').strip()
        passwd = input('password:').strip()
        cpasswd = input('cpassword:').strip()
        if username and passwd and cpasswd:
            if passwd == cpasswd:
                sql = "select * from nhy_user where username='%s';" % username
                if op_mysql(sql):
                    print('用户已经存在！')
                else:
                    md5_password = md5(passwd)
                    sql2 = 'insert into nhy_user (username,password) value ("%s","%s");' % (username, md5_password)
                    op_mysql(sql2)
                    print('注册成功！')
            else:
                print('两次密码输入不一致')
        else:
            print('账号/密码不能为空')


def login():
    username = input('username:').strip()
    passwd = input('passwd:').strip()
    if username and passwd:
        sql = "select password,error_count from nhy_user where username = '%s'" % username
        res = op_mysql(sql)
        print('res======', res)
        if res:
            if res.get('error_count') > 2:
                print('用户已经被锁定')
            else:
                new_passwd = md5(passwd)
                if res.get('password') == new_passwd:
                    print('登录成功！')
                else:
                    print('密码输入错误！')
                    count = res.get('error_count') + 1
                    sql2 = 'update nhy_user set error_count = %s where username = "%s";' % (
                        count, username
                    )
                    op_mysql(sql2)
        else:
            print('用户不存在')


def clear_error_count():
    username = input('username:').strip()
    sql2 = 'update nhy_user set error_count = 0 where username = "%s";' % username
    op_mysql(sql2)


login()
# clear_error_count()