From: "Barry A. Warsaw" <bwarsaw@cnri.reston.va.us>
"Guido" == Guido van Rossum <guido@CNRI.Reston.VA.US> writes:
Guido> The raise could easily enforce this, but it would break Guido> lots of existing code.
Maybe not (I'm not sure). All the standard exceptions inherit from Exception, and of course there'd be nothing to enforce for existing user-defined string based exceptions. How pervasive are user-defined class based exceptions that don't inherit from Exception? (I don't know, and I haven't grepped, but I think we've been making that recommendation from day 1 of class-based standard exceptions, and I try to follow this recommendation in my own code).
Yes, but class-based user exceptions existed many Python versions before class-based standard exceptions! Two examples in the standard library: ConfigParser.py and xdrlib.py.
All Hail, Python 2.0, our Savior and Redeemer! :)
Or, the perfect excuse for procrastination :) (But yes, 2.0 will enforce this.) --Guido van Rossum (home page: http://www.python.org/~guido/)