On Sep 9, 11:43?pm, Dennis Lee Bieber <[EMAIL PROTECTED]> wrote: > On Mon, 10 Sep 2007 01:06:59 GMT, Bryan Olson <[EMAIL PROTECTED]> > declaimed the following in comp.lang.python: > > > They also disagree about integer division. C rounds toward zero; > > Python rounds downward. > > > In C: -111 / 10 evaluates to -11 > > In Python: -111 / 10 evaluates to -12 > > > > Is this a known gotcha? I tried to google the > > > subject however one cannot google the symbol %. > > > I think it's a known gotcha. I cited the refs in another post. > > The best answer is probably to be found from the definition of > divmod() > > > > >>> divmod(70, 6) > (11, 4) > >>> 6*11 + 4 > 70 > >>> divmod(-70, 6) > (-12, 2) > >>> 6 * -12 + 2 > -70 > > Or in general terms > > (a, b) = divmod(x, y) > x = y * a + b
But, in general, doesn't (-11,-4) also satisfy x = y * a + b -70 = 6 * -11 + (-4)? Do you overpay your car loans and wait for a refund? Or do you make your last payment the residue of the debt after making 47 (or whatever) equal payments? > > IOWs, the definition of modulo, and the definition of integer division, > are linked... > > -- > Wulfraed Dennis Lee Bieber KD6MOG > [EMAIL PROTECTED] [EMAIL PROTECTED] > HTTP://wlfraed.home.netcom.com/ > (Bestiaria Support Staff: [EMAIL PROTECTED]) > HTTP://www.bestiaria.com/ -- http://mail.python.org/mailman/listinfo/python-list
