On Mar 8, 5:15 pm, "Terry Reedy" <[EMAIL PROTECTED]> wrote:
> I gave a clear and coherent explanation of how while derives from if,
> and correspondingly, how while-else derives from if-else, to help those who
> want to read and write Python code. Building on the pseudo-snippet above,
> one can write
>
> while loop_condition:
> <loop statements>
> if break_condition:
> <break-only statements>
> break
> <more loop stuff>
> else:
> <completion-only statements>
>
> Python allows one to have both break-only and completion-only sections
> together in one compound statement and *without* having to fiddle with a
> special flag variable. I am sorry if you cannot appreciate such elegance
> and can only spit on it as 'orwellian'.
Just to play Devil's advocate, there is one draw drawback to "such
elegance": when there are multiple break statements. Which means
you'd have to duplicate the break-only condition, or refactor somehow
(which may or may not be suitable).
There have been a couple occasions where I felt the best solution was
to a temporary varible like so:
completed = False
while loop_condition:
<loop statements>
if break_condition:
break
<more loop stuff>
if some_other_break_condition:
break
<more loop stuff>
else:
completed = False
if not completed:
<break-only statements>
It felt icky but we're all still here so it couldn't have been that
bad.
Carl Banks
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