PEP 315: Enhanced While Loop

[Marcus Alanen]

On Mon, 5 May 2003 15:54:58 -0400, rzed <Dick.Zantow at lexisnexis.com> wrote:
>Andrew says that this:
>
>>         while <condition1>:
>>             <code1>
>>         and while <condition2>:
>>             <code2>
>>         and while <condition3>:
>>             <code3>
>
>would be equivalent to this:
>
>>
>>         while <condition1>:
>>             <code1>
>>             if not (<condition2>): break
>>             <code2>
>>             if not (<condition3>): break
>>             <code3>
>>
>... which means that the first 'while' and the second do not mean the
>same thing. That's less than "obvious" (ergo, less than "Pythonic"?).
>If "while" does not imply a looping construct, why use the word?

while <condition1>:
	<code1>
	break unless <condition2>
	<code2>
	break unless <condition3>
	<code3>

Too Perlish?-) But it does read rather good, in my humble opinion.
Even "break if not <condition>" could be a small readability improvement,
the eye ought to see the "break" word easier. Since list comprehensions
have an optional if part, why can't break?

>I'd still prefer to see an indention of the entire while block,
>though -- it seems more obvious:
>
>while <condition1>:
>    <code1>
>    and if <condition2>:
>        <code2>
>    and if <condition3>:
>        <code3>

Not that much difference between it and the standard
"if not condition2: break" code.

Marcus