Alternative to possessive quantifier in python

Question

I am trying to match all occurences of the String Article followed by a number (single or more digits) which are not followed by an opening parentheses. In Sublime Text, I am using the following regex:

Article\s[0-9]++(?!\()

to search the following String:

Article 29
Article 30(1)

which does not match Article 30(1) (as I expect it to) but Article 29 and Article 1.

When attempting to do the same in Python (3) using

import re
article_list = re.findall(r'Article\s[0-9]++(?!\()', "Article 30(1)")

I get an the following Error as I am using a (nested) possessive quantifier which is not supported by Python regex. Is there any way to match what I want it (not) to match in Python?

Answer 1

You can also emulate an atomic group (?>...) around what you want to match, using the (?=(...))\1 workaround:

(?=(Article\s[0-9]+))\1(?!\()

(a lookahead behaves naturally like an a atomic group, all you need is a capture and a backreference)