From: Tim Peters Date: Sat, 10 Jun 2006 22:54:19 +0000 (+0000) Subject: Merge rev 46840 from trunk. X-Git-Tag: v2.4.4c1~181 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b94051562c4dfcb60341bfcb2fbd558e3639703f;p=thirdparty%2FPython%2Fcpython.git Merge rev 46840 from trunk. shuffle() doscstring: Removed warning about sequence length versus generator period. While this was a real weakness of the older WH generator for lists with just a few dozen elements, and so could potentially bite the naive ;-), the Twister should show excellent behavior up to at least 600 elements. --- diff --git a/Lib/random.py b/Lib/random.py index dcceea92055e..3795b4211d8e 100644 --- a/Lib/random.py +++ b/Lib/random.py @@ -29,13 +29,12 @@ General notes on the underlying Mersenne Twister core generator: * The period is 2**19937-1. -* It is one of the most extensively tested generators in existence -* Without a direct way to compute N steps forward, the - semantics of jumpahead(n) are weakened to simply jump - to another distant state and rely on the large period - to avoid overlapping sequences. -* The random() method is implemented in C, executes in - a single Python step, and is, therefore, threadsafe. +* It is one of the most extensively tested generators in existence. +* Without a direct way to compute N steps forward, the semantics of + jumpahead(n) are weakened to simply jump to another distant state and rely + on the large period to avoid overlapping sequences. +* The random() method is implemented in C, executes in a single Python step, + and is, therefore, threadsafe. """ @@ -253,11 +252,6 @@ class Random(_random.Random): Optional arg random is a 0-argument function returning a random float in [0.0, 1.0); by default, the standard random.random. - - Note that for even rather small len(x), the total number of - permutations of x is larger than the period of most random number - generators; this implies that "most" permutations of a long - sequence can never be generated. """ if random is None: