How do I find all lines not containing a specific word?

Question

In my case I want to find (using python regex) all lines not containing the words "error" or "empty". In code:

varformals : PAR_OPEN PAR_CLOSE {}
| PAR_OPEN varform PAR_CLOSE {}
/* error / | error PAR_CLOSE {}
/ error / | error varform PAR_CLOSE {}
/ error */ | PAR_OPEN error PAR_CLOSE {}
;

The use of regex makes sense, I'm pretty sure this is a duplicate, make edits if you believe this is not the case. — Rob Murray, Nov 23 '15 at 15:13
Actually "Python Regex" is different from regex. (pythex simulator[pythex.org]) Also I prefer a "python regex", but if you have a good alternative please post. :D — HackSlash, Nov 24 '15 at 10:29

abc123 · Answer 1 · 2015-11-23T15:43:28.267

1

Regex101

(^((?!error|empty).)*$)

Regular expression visualization

Debuggex Demo

description

1st Capturing group (^((?!error|empty).)*$)
    ^ assert position at start of a line
2nd Capturing group ((?!error|empty).)*
    Quantifier: * Between zero and unlimited times, as many times as possible, giving back as needed [greedy]
    Note: A repeated capturing group will only capture the last iteration.
    Put a capturing group around the repeated group to capture all 
    iterations or use a non-capturing group instead if you're not interested 
    in the data
    (?!error|empty) Negative Lookahead - Assert that it is impossible to match the regex below
        1st Alternative: error
            error matches the characters error literally (case sensitive)
        2nd Alternative: empty
            empty matches the characters empty literally (case sensitive)
    . matches any character (except newline)
$ assert position at end of a line
g modifier: global. All matches (don't return on first match)
m modifier: multi-line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)

edited Nov 23 '15 at 15:43

answered Nov 23 '15 at 15:17

abc123

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Only the word 'empty' is missing as in OP's question: `(?!error|empty)` – agold Nov 23 '15 at 15:31
@agold thanks for pointing that out, updated answer – abc123 Nov 23 '15 at 15:43
First I also thought this was the answer, but this regular regex statement apparently don't work with python regex. (to test see: pythex.org) – HackSlash Nov 24 '15 at 10:25
@HackSlash i just went to pythex.org and it works exactly the same you need to enable the multi-line flag – abc123 Nov 24 '15 at 15:47

How do I find all lines not containing a specific word?

1 Answers1