Problem with lookahead

Stacey Barr — Mon, 03 Feb 2020 19:00:44 -0000

Ah! I see what you meant now. I started learning Python and regex thanks to this add in. I like how elegent and streamlined that addition was, and it worked perfectly. Thanks for the input!

Problem with lookahead

Sasumner — Sat, 01 Feb 2020 15:13:46 -0000

Right at the front, just like I said. I tried it with your data set and got the results you expected.

editor.rereplace(r"(?s)(^F1 VA \d+ )(?=.*\1)", r"! \1")

without the (?s) the . won't match end-of-line characters. With it, it will. That way you can still use the . and don't have to resort to the [\s\S] trick (although that works fine, too).

Aside: When you use the .* pattern, you should always first consider using it as .*? so that it matches minimally.

Problem with lookahead

Stacey Barr — Fri, 31 Jan 2020 18:37:20 -0000

I tried using your suggestion in a number of different ways, but didn't have any luck. Where in the line were you expecting it to go?

Problem with lookahead

Sasumner — Thu, 30 Jan 2020 12:42:29 -0000

"single line flag"?
"Pythonscript wants..." -> it's about what YOU want :-)

I think I see what you are saying though.
You could have left your original regex alone and just added (?-s)to the front of it.

Problem with lookahead

Stacey Barr — Wed, 29 Jan 2020 20:30:22 -0000

Found the solution. For future reference, Python Scrip wants to see the single line flag used in the search.
editor.rereplace(r"(^F1 VA \d+ )(?=[\s\S]*\1)",r"! \1")

Problem with lookahead

Stacey Barr — Wed, 29 Jan 2020 17:22:27 -0000

Does Python Script support lookahead? I’m trying to get this regex to work, but it keeps failing.

editor.rereplace(r"(^F1 VA \d+ )(?=.*\1)", r"! \1")

For more backstory (and an example dataset), here’s a link to a reddit post.
https://www.reddit.com/r/regex/comments/eutmta/finding_duplicates_using_a_lookahead/

Thanks in advance for any input! This is driving me crazy.

Recent posts to Problem with lookahead

Problem with lookahead

Problem with lookahead

Problem with lookahead

Problem with lookahead

Problem with lookahead

Problem with lookahead