[Python-Dev] trunc()

Russell E. Owen rowen at cesmail.net
Mon Jan 28 18:13:29 CET 2008


In article 
<79990c6b0801250553l2e6247adudf48112436dcda70 at mail.gmail.com>,
 "Paul Moore" <p.f.moore at gmail.com> wrote:

> On 24/01/2008, Jeffrey Yasskin <jyasskin at gmail.com> wrote:
> > int has to be a builtin because it's a fundamental type. trunc()
> > followed round() into the builtins. I have no opinion on whether ceil
> > and floor should move there; it probably depends on how often they're
> > used.
> 
> Suggestion:
> 
> - int() has to stay in builtins for obvious reasons.
> - put *all* of trunc, ceil, floor, round into math.
> - make int(float) an error

I like all of your suggestions except the last one. Remember the problem 
with a/b depending on whether b happened to be a float or an int? I 
think you'll be creating a very similar problem here. In my opinion 
int(foo) should do its best to turn foo into an int with *predictable* 
behavior.

The least surprising behavior for int(float) is probably trunc(float). 
Personally I prefer round(float), but I doubt it is worth breaking code 
and retraining everybody.

-- Russell



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