From: Terry Reedy Date: Wed, 10 Nov 2010 17:50:26 +0000 (+0000) Subject: Issue 2986: document heuristic for 3.1 X-Git-Tag: v3.1.3rc1~9 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=c40b25fd682ca48182d351c9b5089423fdcacb80;p=python Issue 2986: document heuristic for 3.1 --- diff --git a/Doc/library/difflib.rst b/Doc/library/difflib.rst index 433764c6c5..c9d1eee880 100644 --- a/Doc/library/difflib.rst +++ b/Doc/library/difflib.rst @@ -35,6 +35,11 @@ diffs. For comparing directories and files, see also, the :mod:`filecmp` module. complicated way on how many elements the sequences have in common; best case time is linear. + **Heuristic:** To speed-up matching, items whose duplicates appear more than 1% of + the time in sequences of at least 200 items are treated as junk. This has the + unfortunate side-effect of giving bad results for sequences constructed from + a small set of items. An option to turn off the heuristic will be added to + Python 3.2. .. class:: Differ