[Python-ideas] Suggestion: Extend integers to include iNaN

[Chris Angelico]

On Mon, Oct 1, 2018 at 8:53 AM Oscar Benjamin
<oscar.j.benjamin at gmail.com> wrote:
>
> On Sun, 30 Sep 2018 at 02:01, Steven D'Aprano <steve at pearwood.info> wrote:
> >
> > On Sat, Sep 29, 2018 at 09:43:42PM +0100, Oscar Benjamin wrote:
> > > On Sat, 29 Sep 2018 at 19:38, Steve Barnes <gadgetsteve at live.co.uk> wrote:
> >
> > > > > I converted to int because I needed a whole number, this was intended to
> > > > represent some more complex process where a value is converted to a
> > > > whole number down in the depths of the processing.
> > >
> > > Your requirement to have a whole number cannot meaningfully be
> > > satisfied if your input is nan so an exception is the most useful
> > > result.
> >
> > Not to Steve it isn't.
> >
> > Be careful about making value judgements like that: Steve is asking for
> > an integer NAN because for *him* an integer NAN is more useful than an
> > exception. You shouldn't tell him that he is wrong, unless you know his
> > use-case and his code, which you don't.
>
> Then he can catch the exception and do something else. If I called
> int(x) because my subsequent code "needed a whole number" then I would
> definitely not want to end up with a nan. The proposal requested is
> that int(x) could return something other than a well defined integer.
> That would break a lot of code!

At no point was the behaviour of int(x) ever proposed to be changed.
Don't overreact here. The recommended use-case was for a library to
return iNaN instead of None when it is unable to return an actual
value.

ChrisA