Regular expression for printing integers within brackets

Question

First time ever using regular expressions and can\'t get it working although there\'s quite a few examples in stackoverflow already.

How can I extract integers which are

Answer 1

If you've not done so I suggest you switch to the PyPI regex module. Using it here with regex.findall and the following regular expression allows you to extract just what you need.

r'\[ *\+?\K-?\d+(?= *\])'

regex engine _{^<¯\(ツ)/¯^>} Python code

At the regex tester pass your cursor across the regex for details about individual tokens.

The regex engine performs the following operations.

\[       : match '['
\ *      : match 0+ spaces
\+?      : optionally match '+'
\K       : forget everything matched so far and reset
           start of match to current position
-?       : optionally match '-'
\d+      : match 1+ digits
(?= *\]) : use positive lookahead to assert the last digit
         : matched is followed by 0+ spaces then ']'