Round a decimal number

[Peter Hansen]

Manuel wrote:
> 
> > If you want to round the number itself, it might be a good idea to
> > post here why you do, in case it's not a good idea and there are
> > better ways to do it (eg, in financial applications).
> 
> Thanks to all.
> :-)
> 
> I'm writing a simple exporter of 3D file format.
> In some cases, in the generated file, I've a numbers like
> 
> 8.70421814625e-008
> 
> The problem is that the "e-008" can't be used
> in the client 3d software. I must round it??

Does this help?

>>> f = 8.70421814625e-008
>>> f
8.7042181462500001e-008
>>> print f
8.70421814625e-008
>>> print '%f' % f
0.000000
>>> print '%g' % f
8.70422e-008

Check the documentation for the % formatting operator to learn more.

-Peter