# [Python-Dev] Re: [Patches] PC\config.[hc] changes for Win64

M.-A. Lemburg mal@lemburg.com
Tue, 09 May 2000 11:09:40 +0200

```Guido van Rossum wrote:
>
> > [Trent]
> > > What if someone needs to do something in Python code for either Win32 or
> > > Win64 but not both? Or should this never be necessary (not
> > > likely). I would
> > > like Mark H's opinion on this stuff.
>
> [Mark]
> > OK :-)
> >
> > I have always thought that it _would_ move to "win64", and the official way
> > of checking for "Windows" will be sys.platform[:3]=="win".
> >
> > In fact, Ive noticed Guido use this idiom (both stand-alone, and as :if
> > sys.platform[:3] in ["win", "mac"])
> >
> > It will no doubt cause a bit of pain, but IMO it is cleaner...
>
> Hmm...  I'm not sure I agree.  I read in the comments that the _WIN32
> symbol is defined even on Win64 systems -- to test for Win64, you must
> test the _WIN64 symbol.  The two variants are more similar than they
> are different.
>
> While testing sys.platform isn't quite the same thing, I think that
> the same reasoning goes: a win64 system is everything that a win32
> system is, and then some.
>
> So I'd vote for leaving sys.platform alone (i.e. "win32" in both
> cases), and providing another way to test for win64-ness.

Just curious, what's the output of platform.py on Win64 ?