[Python-ideas] for/else syntax

Yuvgoog Greenle ubershmekel at gmail.com
Sat Oct 3 17:39:53 CEST 2009

Document it as much as you want but the "else" doesn't hint or clue as
to whether it catches breaks or is skipped by them.

The next problem's gonna be at midnight when you're reading code and
asking yourself "hmmm, for, blah blah, else, hmm oh yeah, else-break,
so this else occurs whenever there's a break."

On Sat, Oct 3, 2009 at 6:27 PM, Ron Adam <rrr at ronadam.com> wrote:
> Nick Coghlan wrote:
>> Ron Adam wrote:
>>> Nick Coghlan wrote:
>>>> Nick Coghlan wrote:
>>>> For a loop with no break statements the else clause will *always* be
>>>> executed, hence using the clause is completely redundant - the code it
>>>> contains might as well be dedented and placed inline at the same level
>>>> as the loop header.
>>> The loop could have a "return", "raise", or be inside a "try/except"
>>> instead of having a "break".
>> As I've said elsewhere in this thread, while the else clause won't be
>> executed in those cases, neither will any code that occurs immediately
>> after the loop statement. Accordingly, using the else clause is
>> unnecessary and rather misleading - just writing the extra code after
>> the loop would be much clearer.
>> The number one thing I have learned from this thread is the fact that
>> the else clause only makes sense when used in conjunction with a break
>> statement and the fact that this construct isn't regularly documented
>> and explained as for/break/else and while/break/else is the major
>> barrier to understanding what it does.
>> Cheers,
>> Nick.
> Ahh, Ok, I agree.  Documenting them as for/break/else and while/break/else
> would probably reduce 80% of the confusion people have with it.
> Ron
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