[Tutor] and-or precedence

[paul brian]

<and> has a higher priority than <or> (as shown on the page you
referenced -its "ascending priority"). Perhaps that could be clearer.

I find that brackets always make life easier in these cases (a rare
statement in the Python world :-), and on a personal note I would
always always comment heavily boolean operations that are not
immediately obvious. it saves brain ache later on.

>>> ((1 or 2) and 3)
3

However 1 or 2 and 3 is <1> if <and> is evaluated first.

cheers


On 10/10/05, Krishna <calvinkrishy at gmail.com> wrote:
> >>> 1 or 2 and 3
> 1
>
> Why does the above expression return 1? As per my understanding of
> boolean operations, this is what should have happaned:
>
> 1 or 2 => 1 and then
> 1 and 3 => 3
>
> The library reference also suggests that 'or' has higher priority than 'and'.
> http://docs.python.org/lib/boolean.html
>
> Thanks
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
>


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