[Python-Dev] Caching float(0.0)

Tim Hochberg tim.hochberg at ieee.org
Mon Oct 2 19:43:51 CEST 2006


skip at pobox.com wrote:\/
>     Steve> By these statistics I think the answer to the original question
>     Steve> is clearly "no" in the general case.
> 
> As someone else (Guido?) pointed out, the literal case isn't all that
> interesting.  I modified floatobject.c to track a few interesting
> floating point values:
> 
[...code...]
> 
> So for a largely non-floating point "application", a fair number of floats
> are allocated, a bit over 25% of them are -1.0, 0.0 or +1.0, and nearly 50%
> of them are whole numbers between -10.0 and 10.0, inclusive.
> 
> Seems like it at least deserves a serious look.  It would be nice to have
> the numeric crowd contribute to this subject as well.

As a representative of the numeric crowd, I'll say that I've never 
noticed this to be a problem. I suspect that it's a non issue since we 
generally store our numbers in arrays, not big piles of Python floats, 
so there's no opportunity for identical floats to pile up.

-tim



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