https://github.com/python/cpython/commit/5c3270939c09e4c8e80fd26449b718a9987... commit: 5c3270939c09e4c8e80fd26449b718a998701912 branch: master author: Raymond Hettinger <rhettinger@users.noreply.github.com> committer: GitHub <noreply@github.com> date: 2020-08-01T01:18:26-07:00 summary: bpo-41421: Algebraic simplification for random.paretovariate() (GH-21695) files: A Misc/NEWS.d/next/Library/2020-08-01-00-51-15.bpo-41421.dHKRVB.rst M Lib/random.py diff --git a/Lib/random.py b/Lib/random.py index a6454f520df0a..37f71110403ad 100644 --- a/Lib/random.py +++ b/Lib/random.py @@ -749,7 +749,7 @@ def paretovariate(self, alpha): # Jain, pg. 495 u = 1.0 - self.random() - return 1.0 / u ** (1.0 / alpha) + return u ** (-1.0 / alpha) def weibullvariate(self, alpha, beta): """Weibull distribution. diff --git a/Misc/NEWS.d/next/Library/2020-08-01-00-51-15.bpo-41421.dHKRVB.rst b/Misc/NEWS.d/next/Library/2020-08-01-00-51-15.bpo-41421.dHKRVB.rst new file mode 100644 index 0000000000000..cf291c60d8ad5 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2020-08-01-00-51-15.bpo-41421.dHKRVB.rst @@ -0,0 +1,3 @@ +Make an algebraic simplification to random.paretovariate(). It now is +slightly less subject to round-off error and is slightly faster. Inputs that +used to cause ZeroDivisionError now cause an OverflowError instead.