python中mysql的上下文管理的封装

class DB(object):
    def __init__(self):
        self.conn = connect(host='localhost', port=3306, database=DATABASE, user='root', password='123456',
                            charset='utf8')
        self.cos = self.conn.cursor()

    def __enter__(self):
        return self.cos

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.conn.commit()
        self.conn.close()
        self.cos.close()

用法

with DB() as db :
    sql ="select * from t_journal_info"
    db.excute(sql)
    result = db.fetchall()