[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Changes by Gregory P. Smith : -- nosy: -gregory.p.smith ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe: https:/

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Changes by Gregory P. Smith : -- assignee: gregory.p.smith -> ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe: h

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Tim Peters added the comment: I'm sympathetic, but I don't see a good solution here without using incompatible code. ndiff was built to generate "the highest quality diff possible", for text written and edited by humans, where "quality" is measured by human judgment (not an abstract mathemati

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Changes by Raymond Hettinger : -- nosy: +tim.peters ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Changes by Gregory P. Smith : -- versions: +Python 3.4, Python 3.5 -Python 3.2, Python 3.3 ___ Python tracker ___ ___ Python-bugs-list

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Changes by Gregory P. Smith : -- assignee: -> gregory.p.smith nosy: +gregory.p.smith ___ Python tracker ___ ___ Python-bugs-list maili

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Christopher Cabanne added the comment: Sorry about the typo; here is the corrected timeit command: python -m timeit -n 10 "import difflib; difflib.HtmlDiff().make_table(open('left500.txt').readlines(), open('right500.txt').readlines())" -- ___ Py

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Christopher Cabanne added the comment: Here is a timeit command to test with the attached test files: python -m timeit -n 10 "import difflib; difflib.HtmlDiff().make_table(open('left500.txt').readlines(), open('righ500.txt').readlines())" -- ___ P

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Christopher Cabanne added the comment: I ran into the slowness of difflib.HtmlDiff.make_table yesterday, and see this issue is three years stale now; is there any update or chance that the fix will be applied? -- nosy: +Christopher.Cabanne ___ Pytho

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Changes by Matt Wheeler : -- nosy: +funkyhat ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Éric Araujo added the comment: The patch by Filip does not add new features, so I’m adjusting versions. I cannot review the patch only by reading it, but if someone gives me a timeit command I can post a benchmark for my Debian machine. -- nosy: +eric.araujo versions: +Python 2.7, Pyt

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Filip Gruszczyński added the comment: Here it is. -- keywords: +patch Added file: http://bugs.python.org/file21588/11740.patch ___ Python tracker ___

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Terry J. Reedy added the comment: Filip, you can look at the changed Benjamin made. One needs to be OP or have admin privileges to change the headers. Could you reupload your patch to this issue? -- versions: +Python 3.3 -Python 3.2 ___ Python trac

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Filip Gruszczyński added the comment: I have no idea how I should do this. If you explain to me, how it should be done, I'll be happy to do this from now on :-) -- ___ Python tracker __

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Charles-Francois Natali added the comment: > Check also this: > > http://bugs.python.org/issue11740 You should indicate it as duplicate. -- ___ Python tracker ___ __

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Filip Gruszczyński added the comment: Check also this: http://bugs.python.org/issue11740 -- nosy: +gruszczy ___ Python tracker ___ __

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Terry J. Reedy added the comment: An api addition makes this a feature request. Heiðar, Please copy of difflib.py, hand patch HtmlDiff to use unified_diff instead of ndiff, and see if that solves the problem. -- nosy: +terry.reedy type: performance -> feature request versions: +Pytho

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Changes by Daniel Bengtsson : -- nosy: +zitrax ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.pytho

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Charles-Francois Natali added the comment: This is because difflib.ndiff (called by difflib.HtmlDiff.make_table), contrarily to difflib.unified_diff (and probably kdiff3), doesn't restrict itself to contiguous lines, and searches diff even inside lines, so the complexity is much worse (see ho

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Jack Diederich added the comment: Here is a profile run of the 200 line case, run on the 3.x trunk, and with all the trivial functions removed. quick_ratio and __contains__ dominate the time. The process was CPU bound, memory usage stayed low. 17083154 function calls (17066360 primitive c

[issue6931] dreadful performance in difflib: ndiff and HtmlDiff

Changes by Heiðar Rafn Harðarson : -- title: awful performance in difflib: ndiff and HtmlDiff -> dreadful performance in difflib: ndiff and HtmlDiff ___ Python tracker ___ __