[Python-Dev] Mixing float and Decimal -- thread reboot

Alexander Belopolsky alexander.belopolsky at gmail.com
Mon Mar 22 19:22:43 CET 2010

On Mon, Mar 22, 2010 at 1:56 PM, Raymond Hettinger
<raymond.hettinger at gmail.com> wrote:
> On Mar 22, 2010, at 10:00 AM, Guido van Rossum wrote:
>   Decimal + float --> Decimal
> If everybody associated with the Decimal implementation wants this I
> won't stop you; as I repeatedly said my intuition about this one (as
> opposed to the other two above) is very weak.
> That's my vote.

I've been lurking on this thread so far, but let me add my +1 to this
option.  My reasoning is that Decimal is a "better" model of Real than
float and mixed operations should not degrade the result.   "Better"
can mean different things to different people, but to me the tie
breaker is the support for contexts.  I would not want precision to
suddenly change in the middle of calculation I add 1.0 instead of 1.

This behavior will also be familiar to users of other "enhanced"
numeric types such as NumPy scalars.   Note that in the older Numeric,
it was the other way around, but after considerable discussion, the
behavior was changed.

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