(no) fast boolean evaluation ?

[Evan Klitzke]

On 8/2/07, Stef Mientki <S.Mientki-nospam at mailbox.kun.nl> wrote:
> hello,
>
> I discovered that boolean evaluation in Python is done "fast"
> (as soon as the condition is ok, the rest of the expression is ignored).
>
> Is this standard behavior or is there a compiler switch to turn it on/off ?
>

This is standard behavior in every language I've ever encountered. If
you are evaluating an and/or with side effects and you need both side
effects to occur, you can trivially write functions implementing this
behavior, e.g.

def a():
    print 'foo'
def b():
    print 'bar'
def my_and(lh, rh):
    return a and b

Then my_and(a(), b()) will evaluate both a and b and print both foo
and bar even though a() is False.

-- 
Evan Klitzke <evan at yelp.com>