Exception.__init__ needed in derived class?

[george young]

On Wed, 23 Apr 2003 14:07:54 -0400
george young <gry at ll.mit.edu> threw this fish to the penguins:
> [python-2.3a1]
> Does class Exception have a constructor __init__ that needs
> to be called?  I couldn't find this in the docs.  I see many
> uses of inheriting from Exception without invoking
> Exception.__init__(self), but nobody ever *said* that this 
> was safe to leave out...
> 
> Pychecker complains about this, which is what brought it to
> mind.  I can certainly invoke it just to make pychecker 
> happy, but I wondered...

To elaborate, I often want to define a __init__ for my
Exception subclass because I want to give it named data, e.g.:

class BadRun(Exception):
	def __init__(self, name, id):
		self.name=name
		self.id=id
...
	raise BadRun(newname, current_id)
...
	try:
		self.run = Run('implant_test', self.step_id)
	except BadRun, x:
		print 'Run %s, id=%s can not be created',x.name, x.id

Would it be better to do:
class BadRun(Exception): pass
...
	ex = BadRun()
	ex.name='implant_test'; ex.id=self.step_id
	raise ex