need clarification on -0

moijes12 moijes12 at gmail.com
Sat Nov 28 09:45:08 CET 2009


On Nov 28, 12:55 pm, Erik Max Francis <m... at alcyone.com> wrote:
> moijes12 wrote:
> > I know the value -0 is quite meaningless and makes little sense.But I
> > was just fiddling.I am unable to figure out the below result
>
> >>>> -0 and True
> > 0 ----------> (Why is this 0 and not say True or False)
> >>>> -0 and false
> > 0
> >>>> -0 or True
> > True
>
> > Could someone please provide me some resources on how these operations
> > take place.I'd wanna find it out myself
>
> Your questions have nothing to do with -0, as it's no different from 0:
>
>  >>> 0 == -0
> True
>
> Your examples work the same way with simply 0, which is considered a
> false value:
>
>  >>> bool(0)
> False
>  >>> 0 and True
> 0
>  >>> 0 and False
> 0
>  >>> 0 or True
> True
>
> What you're seeing is simply the short-circuiting behavior of the `and`
> and `or` operators; they return the last (relevant) value they
> encountered before making their determination of the value of the
> overall expressions.  See python.org/doc for more information.
>
> --
> Erik Max Francis && m... at alcyone.com &&http://www.alcyone.com/max/
>   San Jose, CA, USA && 37 18 N 121 57 W && AIM/Y!M/Skype erikmaxfrancis
>    You'll survive / A true Darwin star
>     -- Des'ree

Thanks Erik



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