[docs] [issue30004] in regex-howto, improve example on grouping

Serhiy Storchaka <storchaka+cpython@gmail.com> added the comment: Do you mind to create a pull request on GitHub Cristian? ---------- components: +Regular Expressions nosy: +ezio.melotti, mrabarnett, serhiy.storchaka stage: -> needs patch versions: -Python 3.3, Python 3.4, Python 3.5 _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue30004> _______________________________________