[Done] Re.sub in client side

Feature Requests
2

While waiting for the real thing my workaround is to use this:

def re_sub(pattern, repl, text):
  groups = re.match(pattern, text)
  if groups:
    for i in range(1, groups.lastindex + 1):
      repl = repl.replace('\\{}'.format(i), groups[i])
  return repl

It works just fine with simple cases like:

>>> re_sub('(\d{3}).*(\d{3}).*(\d{4})', r'(\1) \2-\3', '1234567890')
'(123) 456-7890'
>>> re_sub('(\d{3}).*(\d{3}).*(\d{4})', r'(\1) \2-\3', '123 456 7890')
'(123) 456-7890'