Regex: split new lines between constant words

Question

Given

Word1   content1 content1 content1
       content2 content2 content2
         
          content3 content3 content3
Word2

I want to extract as groups content1, content2 and content3. Could you help to make a regex for that? I tried:

Word1[\s:]*((?P<value>[^\n]+)\n)+Word2 with gms flags, but it didn't help. I need regex for python re module.

Answer 1

You can use

import re
text = "Word1   content1 content1 content1\n       content2 content2 content2\n          content3 content3 content3\nWord2"
match = re.search(r'Word1[\s:]*((?:.+\n)*)Word2', text)
if match:
    print([s.strip() for s in match.group(1).splitlines()])

See the Python and the regex demo .

Output:

['content1 content1 content1', 'content2 content2 content2', 'content3 content3 content3']

Details :

• Word1 - a Word1 string
• [\s:]* - zero or more whitespaces and colons
• ((?:.+\n)*) - Group 1: zero or more repetitions of one or more chars other than line break chars as many as possible, followed with a newline char
• Word2 - a Word2 string.

Then, if there is a match, [s.strip() for s in match.group(1).splitlines()] splits the Group 1 value into separate lines.

An alternative solution using the PyPi regex library can be

import regex
text = "Word1   content1 content1 content1\n       content2 content2 content2\n          content3 content3 content3\nWord2"
print( regex.findall(r'(?<=Word1[\s:]*(?s:.*?))\S(?:.*\S)?(?=(?s:.*?)\nWord2)', text) )

See the Python demo . Details :

• (?<=Word1[\s:]*(?s:.*?)) - a positive lookbehind that requires a Word1 string, zero or more whitespaces or colons, and then any zero or more chars as few as possible immediately to the left of the current location
• \S(?:.*\S)? - a non-whhitespace char and then any zero or more chars other than line break chars as many as possible till the last non-whitespace char on the line
• (?=(?s:.*?)\nWord2) - a positive lookahead that requires any zero or more chars as few as possible and then a newline char and Word2 word to the right of the current location.

Answer 2

Better extract to group everything between 2 words and then split it with new line symbol.

first_key = "Word1"
second_key = "Word2"
common_regex = r"{first_key}[\s:]*(?P<value>.+){second_key}"
regex = common_regex.format(first_key=first_key, second_key=second_key)
lines = [x.group("value").strip() for x in re.finditer(regex, text_piece, re.DOTALL)]
if lines:
    lines = lines[0].split("\n")
else:
    lines = []
print(lines)