Re: Best way to calculate fraction part of x?

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Subject	Re: Best way to calculate fraction part of x?
Date	Thu, 26 Mar 2015 15:02:56 -0700
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On 3/24/15 6:39 PM, Jason Swails wrote:
>
>
> On Mon, Mar 23, 2015 at 8:38 PM, Emile van Sebille <emile@fenx.com
> <mailto:emile@fenx.com>> wrote:
>
>     On 3/23/2015 5:52 AM, Steven D'Aprano wrote:
>
>         Are there any other, possibly better, ways to calculate the
>         fractional part
>         of a number?
>
>
>     float (("%6.3f" % x)[-4:])
>
>
> In general you lose a lot of precision this way...

I suggest modf in the math library:

math.modf(x)
Return the fractional and integer parts of x. Both results carry the 
sign of x and are floats.

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Thread

Best way to calculate fraction part of x? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2015-03-23 23:52 +1100
  Re: Best way to calculate fraction part of x? Skip Montanaro <skip.montanaro@gmail.com> - 2015-03-23 08:02 -0500
  Re: Best way to calculate fraction part of x? Mark Lawrence <breamoreboy@yahoo.co.uk> - 2015-03-23 13:11 +0000
  Re: Best way to calculate fraction part of x? wxjmfauth@gmail.com - 2015-03-23 06:17 -0700
  Re: Best way to calculate fraction part of x? Emile van Sebille <emile@fenx.com> - 2015-03-23 17:38 -0700
  Re: Best way to calculate fraction part of x? Jason Swails <jason.swails@gmail.com> - 2015-03-24 21:39 -0400
  Re: Best way to calculate fraction part of x? Emile van Sebille <emile@fenx.com> - 2015-03-26 13:48 -0700
  Re: Best way to calculate fraction part of x? Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2015-03-26 21:59 +0000
  Re: Best way to calculate fraction part of x? Russell Owen <rowen@uw.edu> - 2015-03-26 15:02 -0700

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