Python学习——使用类封装MySQL

import pymysql
class MySQL:
    def __init__(self,host,port,user,password,db,charset,autocommit):
        try:
            self.conn = pymysql.Connect(host=host,port = port,user=user,password=password,db = db,charset = charset,autocommit =autocommit)
        except Exception as e:
            print("数据库链接错误，错误信息为：%s"%e)
            # raise Exception("数据库链接错误，错误信息为：%s"%e) #主动抛出一个异常
        self.cur = self.conn.cursor(cursor=pymysql.cursors.DictCursor)
    def select_all(self,sql):
        self.sql = str(sql).strip().lower()
        try:
            self.cur.execute(self.sql)
        except Exception as e:
            res = e
            raise Exception("sql语句错误，错误信息：%s"%e)
        else:
            if str[:6]=='select' or str[:6]=='show':
                res = self.cur.fetchall()
            else:
                res = self.sql
        return res
    def select_one(self,sql):
        self.sql = str(sql).strip().lower()
        try:
            self.cur.execute(self.sql)
        except Exception as e:
            res = e
            raise Exception('sql语句错误，错误信息为：s%'%e)
        else:
            if self.sql[:6]=='select' or self.sql[:6]=='show':
                res = self.cur.fetchone()
            else:
                res = self.sql
        return res
    def other_sql(self,sql):
        self.sql = str(sql).strip().lower()
        try:
            self.cur.execute(self.sql)
        except Exception as e:
            res = e
            print("sql语句错误，错误信息为：%s"%e)
        return res
    def close(self):
        print("关闭数据库链接")
        self.cur.close()
        self.conn.close()