At 05:57 PM 1/15/05 -0800, Guido van Rossum wrote:
It's been suggested that all exceptions should inherit from Exception, but this would break tons of existing code, so we shouldn't enforce that until 3.0. (Is there a PEP for this? I think there should be.)
Couldn't we require new-style exceptions to inherit from Exception? Since there are no new-style exceptions that work now, this can't break existing code. Then, the code path is just something like: if isinstance(ob,Exception): # it's an exception, use its type else: # all the other tests done now This way, the other tests that would be ambiguous wrt new-style classes can be skipped, but non-Exception classic classes would still be handled by the existing checks. Or am I missing something?