Bugs item #1054564, was opened at 2004-10-26 14:55
Message generated for change (Comment added) made by effbot
You can respond by visiting:
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1054564&group_id=5470
Category: Regular Expressions
Group: Python 2.2.3
>Status: Closed
>Resolution: Out of Date
>Priority: 9
Submitted By: Rob (rwhent)
Assigned to: Fredrik Lundh (effbot)
Summary: RE '*.?' cores if len of found string exceeds 10000
Initial Comment:
Whilst parsing some extremely long strings I found that the
re.match causes segmentation faults on Solaris 2.8
when strings being matched contain '*.?' and the
contents of the regex which matches this part of the
regex exceeds 10000 chars (actually it seemed to be
exactly at 8192 chars)
This is the regex used:
if re.match('^.*?\[\s*[A-Za-z_0-9]+\s*\].*',string):
This regex looks for '[alphaNum_]' present in a large
string
When it failed the string was 8192 chars long with no
matching '[alphaNum_]' present. If I reduce the length
of the string below 8192 it works ok.
This is a major issue to my application as some string
to be parsed are very large. I saw some discussion on
another bulletin board with a similar issue
----------------------------------------------------------------------
>Comment By: Fredrik Lundh (effbot)
Date: 2005-02-14 12:35
Message:
Logged In: YES
user_id=38376
closing, due to lack of feedback. suggested workarounds
should solve the problem.
----------------------------------------------------------------------
Comment By: Josiah Carlson (josiahcarlson)
Date: 2004-10-30 17:44
Message:
Logged In: YES
user_id=341410
In the case of this particular search, you could write your
own little searcher. The following could likely be done
better, but this is a quick 5-minute job that won't core on
you unless something is really wrong with Python, and may be
a reasonable stopgap until someone re-does the regular
expression library.
import string
def find_thing(s):
sp = 0
d = dict.fromkeys(list(string.letters+string.digits+'_'))
while sp < len(s):
start = None
for i in xrange(sp, len(s)):
if s[i] == '[':
start = i
break
if start is None:
return
for i in xrange(start+1, len(s)):
if s[i] in d:
continue
elif s[i] == ']':
return s[start:i+1]
else:
sp = i
break
It returns None on failure to find, and the string otherwise.
----------------------------------------------------------------------
Comment By: Fredrik Lundh (effbot)
Date: 2004-10-26 15:24
Message:
Logged In: YES
user_id=38376
btw, if you're searching for things, why not use the "search"
method?
if re.search('\[\s*[A-Za-z_0-9]+\s*\]', string):
(also, "[A-Za-z_0-9]" is better spelled "\w")
----------------------------------------------------------------------
Comment By: Fredrik Lundh (effbot)
Date: 2004-10-26 15:20
Message:
Logged In: YES
user_id=38376
The max recursion limit problem in the re module is well-known.
Until this limitation in the implementation is removed, to work
around it check
http://www.python.org/dev/doc/devel/lib/module-re.html
http://python/org/sf/493252
----------------------------------------------------------------------
You can respond by visiting:
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1054564&group_id=5470
_______________________________________________
Python-bugs-list mailing list
Unsubscribe:
http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
