regex python multiline

how can i search for patterns in texts that cover multiple lines and have fixed positions relating each other, for example a pattern consisting of 3 letters of x directly below each other and I want to find them at any position in the line, not just at the beginning for example. Thank you in advance for the answer!


1 Answers regex python multiline

I believe the problem you are asking about is "Find patterns that appear at the same offset in a series of lines."

I do not think this describes a regular language, so you would need to draw on Python's extended regex features to have a chance at a regex-based solution. But I do not believe Python supports sufficiently extended features to accomplish this task [1].

If it is acceptable that they occur at a particular offset (rather than "any offset, so long as the offset is consistent"), then something like this should work:

/^.{OFFSET}PATTERN.*\n^.{OFFSET}PATTERN.*\n^.{OFFSET}PATTERN/, using the MULTILINE flag so that ^ matches the beginning of a series of lines instead of just the beginning of the entire text.

[1] In particular, you could use a backreference to capture the text preceding the desired pattern on one line, but I do not think you can query the length of the captured content "inline". You could search for the same leading text again on the next line, but that does not sound like what you want.

6 days ago