[Tutor] "if n % 2 == 0" vs. "if not n % 2" compared for speed: aesthetics lose

[Richard D. Moores]

On Tue, Nov 23, 2010 at 12:52, Wayne Werner <waynejwerner at gmail.com> wrote:
> On Tue, Nov 23, 2010 at 1:56 PM, Richard D. Moores <rdmoores at gmail.com>
> wrote:
>>
>> On Tue, Nov 23, 2010 at 10:29, R. Alan Monroe <amonroe at columbus.rr.com>
>> wrote:
>> >> I've always disliked using "if not n % 2"  to test for even/odd ints
>> >> because of its convoluted logic. But I ran some speed tests and found
>> >> it was the way to go over "if n % 2 == 0".
>> >
>> > Did you try bitwise-and with 1?
>>
>> What's that?
>
>>>> 2 & 1
> 0
>>>> 3 & 1
> 1
>>>> 10 & 1
> 0
>>>> 11 & 1
> 0
> For an example (base 2):
>        1 0 1 1
>     & 0 0 0 1
> ---------------------
>        0 0 0 1

So what's the connection with the tests I've run?

Dick