正则表达式查找确切的X行

Question

I'm trying to run some regex in python to drop different patterns of text into different files. Turns out, 99+% of all the lines from my source file have a 3-line format like this:

12340987  some other text
          some text
          some text

But then I've got small likelihood that the pattern will have four lines, like this:

123456789   Some text
            Some text
            some text
            one extra line of text

I was trying to write a regex to chase down all the 4-line patterns, and started out with this:

^[0-9]+([\s\S]*?)(?=^[0-9])

How can I build something with a gist like this, but only grab the 4-line pattern? Thanks for reading, and helping if you can. :)

Answer 1

You could try something like this:

^[0-9]+.+$\s(?:^(?!\d).+$\s?){3}

flags gm set

see here https://regex101.com/r/TOoCzF/1

Explanation: ^[0-9]+.+$\\s = Start of line, follows by number and then something, end of line and linebreak

then (?:^(?!\\d).+$\\s?){3} = 3 times a line that does not start with a number