python 用mysqldb方式操作数据库

# -*- coding: utf-8 -*-from User import Userimport time, MySQLdb#连接conn = MySQLdb.connect(host='localhost', user='root', passwd='root', db='test', charset='utf8')cursor = conn.cursor()#写入# sql = "insert into Users values(null, %s, %s)"# for i in range(0, 10):#     param = ('liuruichao', 'nicai')#     result = cursor.execute(sql, param)#     print (result)# conn.commit()# cursor.close()# conn.close()#更新# sql = 'update Users set username=%s where id = %s'# param = ('buzhidao', 2)# result = cursor.execute(sql, param)# print (result)# conn.commit()# cursor.close()# conn.close()#删除# sql = 'delete from Users where id = %s'# param = (2)# result = cursor.execute(sql, param)# print (result)# conn.commit()# cursor.close()# conn.close()#查询list = []sql = 'select * from Users'cursor.execute(sql)rs = cursor.fetchall()for id, username, password in rs:    print ('id : {}, username : {}, password : {}'.format(id, username, password))    user = User()    user.id = id    user.username = username    user.password = password    list.append(user)cursor.close()conn.close()print ('总共有{}人'.format(len(list)))