[Python-Dev] TypeError and AttributeError

Guido van Rossum guido@digicool.com
Wed, 11 Jul 2001 19:26:33 -0400

> >>>>>> "JA" == James Althoff <James_Althoff@i2.com> writes:
> >
> >    JA> would it make sense to make AttributeError a subclass of
> >    JA> TypeError so that
> >
> >    JA> except (TypeError):
> >
> >    JA> would become equally "safe" (and simpler)?
> [Barry]
> >No, but it /might/ make sense to give them a new common base class
> >between them and Exception.  If so, called what?
> ProtocolException.
> I think it would have made sense, but it probably wouldn't have helped.
> Users still see a specific exception thrown and write code against that.

Yeah, the problem with Jim's proposal is that users who write

       "try something"
    except TypeError:
       "one way of handling it"
    except AttributeError:
       "another way of handling it"

will still see a change in behavior, as will users who catch
only AttributeError in a situation that now raises TypeError...

--Guido van Rossum (home page: http://www.python.org/~guido/)