Preferred exception style?

[Bengt Richter]

On Fri, 30 May 2003 14:00:00 -0600, Steven Taschuk <staschuk at telusplanet.net> wrote:

>Quoth George Young:
>  [...]
>> Furthermore, the parenthesis form allows for more than just
>> a string value.  E.g.:
>> class GetRunFailed(Exception):
>> 	def __init__(self, reqobj, dberrormsg=None,
>>                      domainerr='Run does not exist'):
>  [...]
>
>Positional parameters (but not keyword arguments) can be passed
>with the comma syntax, using a tuple in the second place:
>
>    raise GetRunFailed, (reqobj, dberrormsg, domainerr)
>
>The familiar special case for 1-tuples occurs here too, of course.
>
ISTM it could be useful to use keyword parameters and just do self.__dict__.update(kw)
so they'd show up as exception instance attributes, like errno, etc., e.g.,

 >>> class X2(Exception):
 ...     def __init__(self, *args, **kw):
 ...         Exception.__init__(self, *args)
 ...         self.__dict__.update(kw)
 ...
 >>> try:
 ...     raise X2(1,2,3, one=1,two=2)
 ... except Exception, e:
 ...     pass
 ...
 >>> e
 <__main__.X2 instance at 0x007A9C50>
 >>> vars(e)
 {'args': (1, 2, 3), 'two': 2, 'one': 1}
 >>>
 >>> e.__class__.__name__
 'X2'


Regards,
Bengt Richter