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Groups > comp.lang.python > #87829

Re: Best way to calculate fraction part of x?

From Mark Lawrence <breamoreboy@yahoo.co.uk>
Subject Re: Best way to calculate fraction part of x?
Date 2015-03-23 13:11 +0000
References <55100c7a$0$13004$c3e8da3$5496439d@news.astraweb.com>
Newsgroups comp.lang.python
Message-ID <mailman.66.1427116295.10327.python-list@python.org> (permalink)

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On 23/03/2015 12:52, Steven D'Aprano wrote:
> I have a numeric value, possibly a float, Decimal or (improper) Fraction,
> and I want the fractional part. E.g. fract(2.5) should give 0.5.
>
> Here are two ways to do it:
>
> py> x = 2.5
> py> x % 1
> 0.5
> py> x - int(x)
> 0.5
>
> x % 1 is significantly faster, but has the disadvantage of giving the
> complement of the fraction if x is negative:
>
> py> x = -2.75
> py> x % 1
> 0.25
>
> Are there any other, possibly better, ways to calculate the fractional part
> of a number?
>

Any sparks here 
http://stackoverflow.com/questions/875238/fractional-part-of-the-number-question 
?  I'm assuming that the reference to "pkaeding's algorithm" refers to 
https://github.com/pkaeding but haven't confirmed that to be fact.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence

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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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