Compile regex strings from device_tag_re option and return list of compiled regex/tag pairs

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