code: def from_str(cls, tagstring):
          
          m = cls._parse_regexp.match(tagstring)
          return cls(name=m.group('name'), value=m.group('value'), vendor=m.group('vendor'))
docs: Create a tag by parsing the tag of a message
  
          :param tagstring: A tag string described in the irc protocol
          :type tagstring: :class:`str`
          :returns: A tag
          :rtype: :class:`Tag`
          :raises: None