GCD in Fractions

Mark Lawrence breamoreboy at yahoo.co.uk
Wed Sep 24 00:52:54 CEST 2014

On 23/09/2014 22:48, blindanagram wrote:
> On 23/09/2014 20:30, Mark Lawrence wrote:
>> On 23/09/2014 18:43, blindanagram wrote:
>>> On 23/09/2014 18:26, Stefan Behnel wrote:
>>>> Wolfgang Maier schrieb am 23.09.2014 um 18:38:
>>>>> While at first I thought this to be a rather irrelevant debate over
>>>>> module
>>>>> private vs public naming conventions, I now think the OP is probably
>>>>> right
>>>>> and renaming fractions.gcd to fractions._gcd may be a good idea.
>>>> For negative numbers, the "expected" behaviour seems to be unclear,
>>>> so the
>>>> current behaviour is just as good as any, so backwards compatibility
>>>> concerns clearly win this fight.
>>> The expected behaviour is not unclear for anyone who takes the
>>> mathematical properties of the GCD seriously.  It's a shame that Python
>>> doesn't.
>> All you need do is raise an issue on the bug tracker, provide a patch to
>> code, test and docs and the job is done.
> Thank you for your helpful comment.  I will happily do this if after
> discussion here there is a reasonable level of support and encouragement
> for such an action.
> However, there is at least one person here who takes the view that
> backward compatibility outranks mathematical correctness and I don't
> want to find that 'I am banging my head against a brick wall' if this is
> likely to be the stance that Python developers take.

 From https://docs.python.org/devguide/experts.html Mark Dickinson and 
Raymond Hettinger are listed as the maintainers of the fractions module. 
  If they're not lurking here I'd guess the simplest way to contact them 
is via the bug tracker.  That also gives the official mechanism as to 
whether or not an enhancement request such as this is accepted or 
rejected and the rationale behind the decision.  For example it is 
feasible that the current behaviour would be deprecated in Python 3.5 
and changed in 3.6 to match your needs.  I don't have enough knowledge 
of the maths to say one way or another, but I'm certain that others will 
chip in with their comments.  Best of luck anyway :)

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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