[Python-Dev] Fwd: summing a bunch of numbers (or "whatevers")

[Aahz]

On Sun, Apr 20, 2003, Tim Peters wrote:
> [Aahz]
>>
>> Problem is, what *kind* of number?  While ints are in general easily
>> promotable (especially int 0), I'd prefer to make things explicit.
> 
> I'd be OK with changing the signature to
> 
>     sum(iterable, empty=0)
> 
> as 0 cannot in fact be auto-promoted to some reasonable number-like
> objects.  For example, summing a list of datetime.timedelta objects
> seems a quite natural application (e.g., picture a timesheet app), but
> supplying int 0 generally blows up when a timedelta is expected.

+1

That makes the canonical usage clear, while not preventing people from
doing stupid things.  ;-)
-- 
Aahz (aahz@pythoncraft.com)           <*>         http://www.pythoncraft.com/

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