[docs] [issue18779] Misleading documentations and comments in regular expression about alphanumerics and underscore

Changes by Serhiy Storchaka <storchaka@gmail.com>: ---------- components: +Regular Expressions nosy: +ezio.melotti, mrabarnett, pitrou stage: -> patch review _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue18779> _______________________________________