如何正确弃用 Python 中的自定义异常?

How to properly deprecate a custom exception in Python?

我的 Python 项目中有自定义继承异常,我想弃用其中之一。正确的做法是什么?

例外情况:

class SDKException(Exception):
    pass

class ChildException(SDKException):
    pass

class ChildChildException(ChildException):  # this one is to be deprecated
    pass

我想弃用 ChildChildException,考虑到该异常在项目中被使用、引发并与其他异常链接。

您可以使用装饰器,它在异常的每个实例化上显示 warning DeprecationWarning 类别 class:

import warnings

warnings.filterwarnings("default", category=DeprecationWarning)

def deprecated(cls):
    original_init = cls.__init__
    def __init__(self, *args, **kwargs):
        warnings.warn(f"{cls.__name__} is deprecated", DeprecationWarning, stacklevel=2)
        original_init(self, *args, **kwargs)
    cls.__init__ = __init__
    return cls

class SDKException(Exception):
    pass


class ChildException(SDKException):
    pass

@deprecated
class ChildChildException(ChildException):  # this one is to be deprecated
    pass

try:
    raise ChildChildException()    
except ChildChildException:
    pass
app.py:7: DeprecationWarning: ChildChildException is deprecated

更新: 此外,您可以创建自定义警告 class 并将其传递给警告函数:

class ExceptionDeprecationWarning(Warning):
    pass
warnings.warn(f"{cls.__name__} is deprecated", ExceptionDeprecationWarning)