[Tutor] if n == 0 vs if not n

[Andre Engels]

On Tue, Oct 6, 2009 at 5:08 PM, Wayne <srilyk at gmail.com> wrote:
> On Tue, Oct 6, 2009 at 9:58 AM, Dave Angel <davea at ieee.org> wrote:
>>
>> <snip>
>>
>> No, because you're not assured that all integers that are equal are the
>> same object.  Python optimizes that for small integers, but there's no
>> documented range that you can count on it.
>>
>
> But for this specific case - checking a return code against zero, should it
> still be considered unreliable? The only case that you are looking for
> correctness is 0 == 0, any other case should evaluate as false, so I guess
> the question is does python always optimize for zero? Any other optimization
> is irrelevant, AFAIK.

Never rely on optimizations like this being done, or on them not being
done. The only save way to code is having your code work in both
cases.


-- 
André Engels, andreengels at gmail.com