Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
636 views
in Technique[技术] by (71.8m points)

regex - 'negative' pattern matching in python

I have the following input,

OK SYS 10 LEN 20 12 43
1233a.fdads.txt,23 /data/a11134/a.txt
3232b.ddsss.txt,32 /data/d13f11/b.txt
3452d.dsasa.txt,1234 /data/c13af4/f.txt
.

And I'd like to extract all of the input except the line containing "OK SYS 10 LEN 20" and the last line which contains a single "." (dot). That is, I want to extract the following

1233a.fdads.txt,23 /data/a11134/a.txt
3232b.ddsss.txt,32 /data/d13f11/b.txt
3452d.dsasa.txt.1234 /data/c13af4/f.txt

I tried the following,

for item in output:
    matchObj = re.search("^(?!OK) | ^(?!\.)", item)
    if matchObj:
        print "got item "  + item

but it does not work, as it does not produce any output.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

See it in action:

matchObj = re.search("^(?!OK|\.).*", item)

Don't forget to put .* after negative look-ahead, otherwise you couldn't get any match ;-)


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

2.1m questions

2.1m answers

60 comments

57.0k users

...