Notepad++ Selectively delete lines within a file

Question

I have a dual .srt file that looks like this:

1
00:07:14,120 --> 00:07:16,953
[French line]
[Russian line]

2
00:07:16,960 --> 00:07:19,952
[French line]
[Russian line]

3
00:07:21,240 --> 00:07:24,835
[French line]
[Russian line]

I would like to delete all the Russian lines (plus the corresponding CRLF's). Which means lines 4, 9, 14, 19, 24, 29, and so on. It's every 5 lines, starting at line 4.

I guess Notepad++'s "Find in files" should be able to do it with the right RegEx (but I'm open to any solution). Could you please help me with that? Thank you.

Please include your current regex (how far you got), it's helpful for others to understand the context/data you're processing. — bobble bubble, Sep 26 '22 at 13:55
@bobblebubble 's answer solved it beautifully. Plus the regex101 site seems really useful. Many thanks for that! Problem solved. — Jose Hidalgo, Sep 26 '22 at 15:01
@JoseHidalgo Welcome! I think you could further use [`(?>\R?.+){3}\K\R.+`](https://regex101.com/r/Gq8tS6/1) which can be slightly more efficient, I added it to my answer. Glad it helped. — bobble bubble, Sep 26 '22 at 15:30
Does this answer your question? [Reference - What does this regex mean?](https://stackoverflow.com/questions/22937618/reference-what-does-this-regex-mean) — AdrianHHH, Sep 26 '22 at 16:50

bobble bubble · Accepted Answer · 2022-09-26T20:30:21.683

To target every nth line in non empty line sequences:

(?:(?:\R|\A).+){3}\K\R.+

See this demo at regex101 (explanation on right side)

\A matches start of the string
\R matches any newline sequence
\K resets beginning of the reported match
.+ matches one or more of any character (besides newline)
(?: non capturing group ) {3} quantified three times

Click on "replace all" and replace with empty.
Make sure to uncheck [ ] dot matches newline in the replace dialogue.
A bit more efficient alternative with atomic group: (?>\R?.+){3}\K\R.+

Notepad++ Selectively delete lines within a file

1 Answers1