En Fri, 13 Jun 2008 06:15:52 -0300, marc wyburn <[EMAIL PROTECTED]> escribió:

HI all, I'm a bit stuck with how to work out boolian logic.

I'd like to say if A is not equal to B, C or D:
   do something.

I've tried

if not var == A or B or C:
and various permutations but can't seem to get my head around it.  I'm
pretty sure I need to know what is calulated first i.e the not or the
'OR/AND's

if A not in (B, C, D):
  ...

"or" has less priority than not, and all boolean operators have less priority than comparisons. So your expression above reads as:

if (not (var==A)) or B or C

and the three or'ed expressions are evaluated from left to right (short-circuit: stop as soon as any true value is found).

Evaluation order is defined in the Reference Manual, see <http://docs.python.org/ref/expressions.html> in particular, operator precedence is summarized in <http://docs.python.org/ref/summary.html>

--
Gabriel Genellina

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