[Python-3000] Exception Expressions

[Calvin Spealman]

On 8/31/06, Brett Cannon <brett at python.org> wrote:
> So this feels like the Perl idiom of using die: ``open(file) or die`` (or
> something like that; I have never been a Perl guy so I could be off).
>
> > ...
>
> The problem I have with this whole proposal is that catching exceptions
> should be very obvious in the source code.  This proposal does not help with
> that ideal.  So I am -1 on the whole idea.
>
> -Brett

"Ouch" on the associated my idea with perl!

Although I agree that it is good to be obvious about exceptions, there
are some cases when they are simply less than exceptional. For
example, you can do d.get(key, default) if you know something is a
dictionary, but for general mappings you can't rely on that, and may
often use exceptions as a kind of logic control. No, that doesn't sync
with the purity of exceptions, but sometimes practicality and
real-world usage trumps theory.

Only allowing a single expression, it shouldn't be able to get ugly.
Also, maybe I hate to admit it but it could allow 'expr1 except expr2'
as pretty something more like the 'or die' paradigm.