Python DB Access Wrapper

gistfile1.py

import sys
import mysql.connector

def exec_sql(fn):
    def wrapper(*args, **kw):
        _self = args[0]
        _self.con = mysql.connector.connect(**_self.rds_config)
        ret = None
        try:
            ret = fn(*args, **kw)
        finally:
            _self.con.close()
            _self.con = None
        return ret
    return wrapper

class DbBase(object):
    def __init__(self, config):
        self.rds_config = config
        self.con = None

class DataAccessClass:
    @exec_sql
    def some_sql_(self):
        cur = self.con.cursor()
        query =""
        cur.execute(query)