On Thu, Sep 18, 2014 at 1:34 AM, Ian Kelly <ian.g.ke...@gmail.com> wrote: > On Wed, Sep 17, 2014 at 9:29 AM, Chris Angelico <ros...@gmail.com> wrote: >> On Thu, Sep 18, 2014 at 1:16 AM, cool-RR <ram.rac...@gmail.com> wrote: >>> I didn't ask for the modulo, I agree it should remain NaN. I'm talking >>> about the floor division. >>> >> >> Invariant: div*y + mod == x. >> >> If mod is NaN, there is no possible value for div that will make the >> invariant true, ergo it too has to be NaN. > > That still doesn't make the invariant true. By this argument div could > be 42, and the invariant would hold equally well (i.e. not at all).
Nothing can possibly make it true, so there are only two possibilities: return NaN, or raise an exception. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
