[Python-Dev] PEP 342 support for string exceptions in throw() (original) (raw)

Guido van Rossum guido at python.org
Sat Mar 25 00:04:11 CET 2006

On 3/24/06, Phillip J. Eby <pje at telecommunity.com> wrote:

At 02:36 PM 3/24/2006 -0800, Guido van Rossum wrote: >I think it's overkill to warn for any string exceptions thrown this >way. Since the only use case for using throw() is to pass an exception >you just caught, I don't see that putting the warning is useful -- >it's just more code that in practice is never triggered.

My proposal was that throw() should only succeed or fail, never warn. If you throw() a string exception with a traceback, it Just Works. If you throw() a string exception without a traceback, you get an immediate TypeError, just like in the 2.5 trunk now. Is that acceptable? i.e., was that what you were "-0"-ing?

Actually that's slightly worse; I'm not sure we guarantee that exceptions you catch always have a traceback object associated with them. So -1.

The only change is that throw() would now accept string exceptions without warning or error, if and only if you supply a traceback. That is, if you are effectively re-raising an existing exception.

The current state is that it always allows them, right? I don't see a reason to change that, and I don't think you've made a strong argument for changing it -- I don't think the use case matters.

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

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