假设我有一个类，我希望异常由装饰器处理：

class A:

    def __init__(self, start: bool):
        self.start = start

    def enc(self, data):
        try:
            if self.start:
                return data.encode()
            return 'ok'
        except AttributeError:
            raise Exception('oh no')

    def dec(self, data):
        try:
            if self.start:
                return data.decode()
            return 'ok'
        except AttributeError:
            raise Exception('oh no')

我想添加一个decorator来处理异常：如下所示：
（这行不通， @A.type_exc_handler NameError: name 'A' is not defined ):

class A:

    def __init__(self, start: bool):
        self.start = start

    def type_exc_handler(self, func):
        def inner(self, *args,**kwargs):
            try:
                func(self, *args,**kwargs)
            except AttributeError:
                raise TypeError(f"oh no")
            return inner

    @A.type_exc_handler
    def enc(self, data):
        if self.start:
            return data.encode()
        return 'ok'

    @A.type_exc_handler
    def dec(self, data):
        if self.start:
            return data.decode()
        return 'ok'

我怎样才能做到这一点？