Regexp to find caret preceding integers not working

Question

I'm trying to replace this [^19) Jones, Owen. with this [^19] Jones, Owen. using this regexp statement:

re.sub(r'(?<=\[\^[0-9])(\) )','] ', text)

But no replacement occurs and I'm unable to find the issue. Please help.

Remove the space, or use `re.X` option, `re.sub(r'(?<=\[\^[0-9])(\) )','] ', text, flags=re.X)`. There must be no space after `)`. Else, your solution works. — Wiktor Stribiżew, Oct 14 '22 at 15:44
It [does work](https://regex101.com/r/V6sGZM/2). Show your code, only your code might fail here. Also, what error do you get? — Wiktor Stribiżew, Oct 14 '22 at 15:50
Here's exactly what I'm using html = re.sub(r'(?<=\[\^[0-9])(\))',']', html, flags=re.X) And the string that I want to replace is [^19) Jones, Owen. with this [^19] Jones, Owen. — sheharbano, Oct 14 '22 at 15:52

score 1 · Accepted Answer · answered Oct 14 '22 at 15:54

1

You need to use

re.sub(r'(\[\^\d+)\) ', r'\1] ', text)

Details:

(\[\^\d+) - Group 1 (whose value is referred to with \1 from the replacement pattern): [^ and one or more digits
\) - a ) string.

Note you cannot use a lookbehind here, since \d+ matches a non-fixed amount of digits, and Python re lookbehind requires fixed-width patterns.

answered Oct 14 '22 at 15:54

Wiktor Stribiżew

Okay. so the problem was with the lookahead '?<=' that I was using. Thanks for the explanation. – sheharbano Oct 14 '22 at 16:00

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