Bugs item #1566086, was opened at 2006-09-26 21:23 Message generated for change (Comment added) made by akuchling You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1566086&group_id=5470
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Regular Expressions Group: Python 2.4 Status: Open Resolution: None Priority: 5 Private: No Submitted By: Fabien Devaux (fabinator) Assigned to: Gustavo Niemeyer (niemeyer) Summary: RE (regular expression) matching stuck in loop Initial Comment: See the code: http://pastebin.ca/183613 the "finditer()" call don't seems to return. Playing with the re can bypass the problem but it looks like a bug. (I'm really sorry if I did something wrong and didn't notice) note: I can reproduce it with python2.5 ---------------------------------------------------------------------- >Comment By: A.M. Kuchling (akuchling) Date: 2006-10-26 15:53 Message: Logged In: YES user_id=11375 I haven't dug very far into the code, but suspect this isn't a bug in the regex code. The pattern uses lots of .*? subpatterns, and this often means the pattern takes a long time to fail if it isn't going to match. The regex engine matches the <link> group, and then there's a .*?, followed by <b>. The engine looks at every character and if it sees a <b>, tries another .*?. This is O(n**2) where n is the number of character in the string being searched, and that string is 93,000 characters long. If you limit the string to 5K or so, the match fails pretty quickly. I strongly suggest working with the HTML. You could run the HTML through tidy to convert to XHTML and use ElementTree on the resulting XML. ---------------------------------------------------------------------- Comment By: A.M. Kuchling (akuchling) Date: 2006-10-26 15:38 Message: Logged In: YES user_id=11375 Attaching the test script. I've modified it to save a copy of the HTML page's data so that running the example doesn't require accessing a slow web site repeatedly. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1566086&group_id=5470 _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
