Simple if-else question

Terry Reedy tjreedy at udel.edu
Wed Sep 30 10:03:59 CEST 2009


John Yeung wrote:
> On Sep 29, 1:15 pm, Carl Banks <pavlovevide... at gmail.com> wrote:
>> Hmm, I wonder if Python should emit a warning if an else is
>> used on a for block with no break inside.  I don't think the
>> else can be invoked in any other way.  As a bonus it could
>> catch some cases where people mistakenly use it thinking it
>> will execute [only] when there are no iterations.
> 
> [Edit from Duncan Booth]
> 
> I would definitely be in favor of a warning.  Yes, people should read
> the docs more carefully, and yes, it would cost a certain amount of
> annoyance to implement this.  But I don't think it would get in
> people's way if they do know how to use else, and I think it would cut
> down on the number of questions from mystified beginners, some of whom
> are much more aggressive than this particular OP about claiming that
> Python is broken (when it's actually behaving as designed).

This sort of warning is appropriate for code checkers like Pylint, 
Pychecker, but not for the running interpreter.

tjr





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