From: Raymond Hettinger <rhettinger@users.noreply.github.com>
Date: Wed, 30 Jan 2019 21:30:20 +0000 (-0800)
Subject: Document differences between random.choices() and random.choice(). (GH-11703)
X-Git-Tag: v3.8.0a1~32
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=40ebe948e97b47fc84c8f527910063286a174b25;p=python

Document differences between random.choices() and random.choice(). (GH-11703)
---

diff --git a/Doc/library/random.rst b/Doc/library/random.rst
index 4f251574a3..a543ff016a 100644
--- a/Doc/library/random.rst
+++ b/Doc/library/random.rst
@@ -162,6 +162,13 @@ Functions for sequences
    with the :class:`float` values returned by :func:`random` (that includes
    integers, floats, and fractions but excludes decimals).
 
+   For a given seed, the :func:`choices` function with equal weighting
+   typically produces a different sequence than repeated calls to
+   :func:`choice`.  The algorithm used by :func:`choices` uses floating
+   point arithmetic for internal consistency and speed.  The algorithm used
+   by :func:`choice` defaults to integer arithmetic with repeated selections
+   to avoid small biases from round-off error.
+
    .. versionadded:: 3.6