docs: def _compile_tag_re(self):
          """
          Compile regex strings from device_tag_re option and return list of compiled regex/tag pairs
          """
          device_tag_list = []
          for regex_str, tags in iteritems(self._device_tag_re):
              try:
                  device_tag_list.append([re.compile(regex_str, IGNORE_CASE), [t.strip() for t in tags.split(',')]])
              except TypeError:
                  self.log.warning('{} is not a valid regular expression and will be ignored'.format(regex_str))
          self._device_tag_re = device_tag_list