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.

CodePudding user response：

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.