John Gruber's regex to find URLs in plain text, converted to Python/Unicode

gruber_urlintext.py

#See: http://daringfireball.net/2010/07/improved_regex_for_matching_urls
import re, urllib

GRUBER_URLINTEXT_PAT = re.compile(ur'(?i)\b((?:https?://|www\d{0,3}[.]|[a-z0-9.\-]+[.][a-z]{2,4}/)(?:[^\s()<>]+|\(([^\s()<>]+|(\([^\s()<>]+\)))*\))+(?:\(([^\s()<>]+|(\([^\s()<>]+\)))*\)|[^\s`!()\[\]{};:\'".,<>?\xab\xbb\u201c\u201d\u2018\u2019]))')

for line in urllib.urlopen("http://daringfireball.net/misc/2010/07/url-matching-regex-test-data.text"):
    print [ mgroups[0] for mgroups in GRUBER_URLINTEXT_PAT.findall(line) ]

The fix provided by @arunchaganty missing escaping backslashes in the very last exclusion group. Code below adds them back.

GRUBER_URLINTEXT_PAT = re.compile(ur'(?i)\b((?:https?://|www\d{0,3}[.]|[a-z0-9.\-]+[.][a-z]{2,4}/)(?:[^\s()<>]|\(([^\s()<>]+|(\([^\s()<>]+\)))*\))+(?:\(([^\s()<>]+|(\([^\s()<>]+\)))*\)|[^\s`!()\[\]{};:\'".,<>?\xab\xbb\u201c\u201d\u2018\u2019]))')

This regex is awesome, I had to slightly modify it but I found a rare catastrophic backtracking bug with the string below (even without my modifications) :(

http://Download%20(Album%20of%20six%20wallpapers)

The problem is the %20(

Tested here: https://regex101.com/r/DAA8ww/1

Had to resort to using google's re2 (through pyre2 wrapper) instead of python's native re in order to avoid the problem (had to remove the \u escaped unicode characters though).