On 11/22/09 16:05, Helmut Jarausch wrote:
On 11/22/09 14:58, Jelle Smet wrote:
Hi List,
I'm trying to match lines in python using the re module.
The end goal is to have a regex which enables me to skip lines which
have ok and warning in it.
But for some reason I can't get negative lookaheads working, the way
it's explained in "http://docs.python.org/library/re.html";.
Consider this example:
Python 2.6.4 (r264:75706, Nov 2 2009, 14:38:03)
[GCC 4.4.1] on linux2
Type "help", "copyright", "credits" or "license" for more information.
import re
line='2009-11-22 12:15:441 lmqkjsfmlqshvquhsudfhqf qlsfh
qsduidfhqlsiufh qlsiuf qldsfhqlsifhqlius dfh warning qlsfj lqshf
lqsuhf lqksjfhqisudfh qiusdfhq iusfh'
re.match('.*(?!warning)',line)
<_sre.SRE_Match object at 0xb75b1598>
I would expect that this would NOT match as it's a negative lookahead
and warning is in the string.
'.*' eats all of line. Now, when at end of line, there is no 'warning'
anymore, so it matches.
What are you trying to achieve?
If you just want to single out lines with 'ok' or warning in it, why not
just
if re.search('(ok|warning)') : call_skip
Probably you don't want words like 'joke' to match 'ok'.
So, a better regex is
if re.search('\b(ok|warning)\b',line) : SKIP_ME
Helmut.
--
Helmut Jarausch
Lehrstuhl fuer Numerische Mathematik
RWTH - Aachen University
D 52056 Aachen, Germany
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