Regex Search end of line and beginning of next line

Question

Trying to come up with a regex to search for keyword match at end of line and beginning of next line(if present)

I have tried below regex and does not seem to return desired result

re.compile(fr"\s(?!^)(keyword1|keyword2|keyword3)\s*\$\n\r\((\w+\W+|W+\w+))", re.MULTILINE | re.IGNORECASE)

My input for example is

sentence = """ This is my keyword
/n value"""

Output in above case should be keyword value

Thanks in advance

Answer 1

You could match the keyword (Or use an alternation ) to match more keywords and take trailing tabs and spaces into account after the keyword and after matching a newline.

Using 2 capturing groups as in the pattern you tried:

(?<!\S)(keyword)[\t ]*\r?\n[\t ]*(\w+)(?!\S)

Explanation

• (?<!\\S) Negative lookbehind, assert what is directly on the left is not a non whitespace char
• (keyword) Capture in group 1 matching the keyword
• [\\t ]* Match 0+ tabs or spaces
• \\r?\\n Match newline
• [\\t ]* Match 0+ tabs or spaces
• (\\w+) Capture group 2 match 1+ word chars
• (?!\\S) Negative lookahead, assert what is directly on the right is not a non whitespace char

Regex demo | Python demo

For example:

import re

regex = r"(?<!\S)(keyword)[\t ]*\r?\n[\t ]*(\w+)(?!\S)"
test_str = (" This is my keyword\n"
    " value")

matches = re.search(regex, test_str)

if matches:
    print('{} {}'.format(matches.group(1), matches.group(2)))

Output

keyword value

Answer 2

How about \\b(keyword)\\n(\\w+)\\b ?

\b(keyword)\n(\w+)\b

\b                      get a word boundary
  (keyword)             capture keyword (replace with whatever you want)
           \n           match a newline
             (\w+)      capture some word characters, one or more
                  \b    get a word boundary

Because keyword and \\w+ are in capture groups, you can reference them as you wish later in your code.

Try it here!

Answer 3

My guess is that, depending of the number of new lines that you might have, an expression similar to:

\b(keyword1|keyword2|keyword3)\b[r\n]{1,2}(\S+)

might be somewhat close and the value is in \\2 , you can make the first group non-captured, then:

\b(?:keyword1|keyword2|keyword3)\b[r\n]{1,2}(\S+)

\\1 is the value .

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If you wish to explore/simplify/modify the expression, it's been explained on the top right panel of regex101.com . If you'd like, you can also watch in this link , how it would match against some sample inputs.

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