From 92df7529cb6c863d0fcd3247829b24833f62e285 Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Sun, 25 May 2014 17:40:25 -0700 Subject: [PATCH] Issue 13355: Make random.triangular degrade gracefully when low == high. --- Lib/random.py | 5 ++++- Lib/test/test_random.py | 2 +- Misc/NEWS | 3 +++ 3 files changed, 8 insertions(+), 2 deletions(-) diff --git a/Lib/random.py b/Lib/random.py index e89fae663a..3f96a3770b 100644 --- a/Lib/random.py +++ b/Lib/random.py @@ -371,7 +371,10 @@ class Random(_random.Random): """ u = self.random() - c = 0.5 if mode is None else (mode - low) / (high - low) + try: + c = 0.5 if mode is None else (mode - low) / (high - low) + except ZeroDivisionError: + return low if u > c: u = 1.0 - u c = 1.0 - c diff --git a/Lib/test/test_random.py b/Lib/test/test_random.py index ba447ee57a..1a5a86b9e2 100644 --- a/Lib/test/test_random.py +++ b/Lib/test/test_random.py @@ -541,7 +541,7 @@ class TestDistributions(unittest.TestCase): for variate, args, expected in [ (g.uniform, (10.0, 10.0), 10.0), (g.triangular, (10.0, 10.0), 10.0), - #(g.triangular, (10.0, 10.0, 10.0), 10.0), + (g.triangular, (10.0, 10.0, 10.0), 10.0), (g.expovariate, (float('inf'),), 0.0), (g.vonmisesvariate, (3.0, float('inf')), 3.0), (g.gauss, (10.0, 0.0), 10.0), diff --git a/Misc/NEWS b/Misc/NEWS index d46d1d3063..04e9221d94 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -23,6 +23,9 @@ Tests - Issue #19925: Added tests for the spwd module. Original patch by Vajrasky Kok. +- Issue #13355: random.triangular() no longer fails with a ZeroDivisionError + when low equals high. + - Issue #21522: Added Tkinter tests for Listbox.itemconfigure(), PanedWindow.paneconfigure(), and Menu.entryconfigure(). -- 2.50.1