利用with定义函数

@contextlib.contextmanager
def mysql(self, host='127.0.0.1', port=3306, user='nick', passwd='', db='db1', charset='utf8'):
    self.conn = pymysql.connect(host=host, port=port, user=user, passwd=passwd, db=db, charset=charset)
    self.cuersor = self.conn.cursor(cursor=pymysql.cursors.DictCursor)

    try:
        yield self.cuersor
    finally:
        self.conn.commit()
        self.cuersor.close()
        self.conn.close()

执行

with mysql() as cuersor: print(cuersor) # 操作MySQL代码块