32 bit or 64 bit?

[Peter Otten]

ram.rachum at gmail.com wrote:

> On Jun 15, 2:48 pm, Peter Otten <__pete... at web.de> wrote:
>> ram.rac... at gmail.com wrote:
>> > Quick question:
>> > I have python code that does a lot of floating point arithmetic. How
>> > do I make it do the arithmetic in 64 bit? (I have a 64 bit CPU.) If
>> > I'll install a 64-bit operating system, will that do the trick?
>>
>> The Python float type uses a C double internally which is 64 bit even on
>> 32 bit CPUs.
>>
>> Peter
> 
> Does it mean that even now it does arithmetic in 64 bit?

Yes. See

http://en.wikipedia.org/wiki/IEEE_floating-point_standard#Double-precision_64_bit

for details.

> I'm not getting enough precision. Is there any way to increase it?

http://gmpy.sourceforge.net/

If by "not enough precision" you mean you are bothered by

>>> .1
0.10000000000000001

have a look at the decimal module, see

http://docs.python.org/lib/module-decimal.html

Peter