Author Orborde
Recipients Orborde
Date 2014-04-02.23:52:29
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Message-id <1396482750.35.0.873465877702.issue21136@psf.upfronthosting.co.za>
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The following Python runs unnecessarily slowly:

import fractions
fractions.Fraction(6249919, 6250000) ** 89993


The problem here is that Fraction.__pow__ constructs a new Fraction() to return, and Fraction.__new__ tries to gcd to normalize the numerator/denominator. The gcd is very, very slow, and more to the point, unnecessary; raising a normalized fraction to an integer power will always yield another normalized fraction.


fractions.Fraction.__pow__ should use this trick to make the code snippet above fast.
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Date User Action Args
2014-04-02 23:52:30Orbordesetrecipients: + Orborde
2014-04-02 23:52:30Orbordesetmessageid: <1396482750.35.0.873465877702.issue21136@psf.upfronthosting.co.za>
2014-04-02 23:52:30Orbordelinkissue21136 messages
2014-04-02 23:52:29Orbordecreate