Python regex, remove all punctuation except hyphen for unicode string

Question

I have this code for removing all punctuation from a regex string:

import regex as re    
re.sub(ur"\p{P}+", "", txt)

How would I change it to allow hyphens? If you could explain how you did it, that would be great. I understand that here, correct me if I'm wrong, P with anything after it is punctuation.

Answer 1

[^\P{P}-]+

\P is the complementary of \p - not punctuation. So this matches anything that is not (not punctuation or a dash) - resulting in all punctuation except dashes.

Example: http://www.rubular.com/r/JsdNM3nFJ3

If you want a non-convoluted way, an alternative is \p{P}(?<!-): match all punctuation, and then check it wasn't a dash (using negative lookbehind).
Working example: http://www.rubular.com/r/5G62iSYTdk