def fetch_woeid(self, location):
        """Fetch a location's corresponding WOEID.

        Args:
            location: (string) a location (e.g. 23454 or Berlin, Germany).

        Returns:
            a string containing the location's corresponding WOEID or None if
                the WOEID could not be found.

        Raises:
            urllib.error.URLError: urllib.request could not open the URL
                (Python 3).
            urllib2.URLError: urllib2 could not open the URL (Python 2).
            xml.etree.ElementTree.ParseError: xml.etree.ElementTree failed to
                parse the XML document.

        """
        rss = self._fetch_xml(
            WOEID_LOOKUP_URL.format(quote(location)))
        try:
            woeid = rss.find("results/Result/woeid").text
        except AttributeError:
            return None
        return woeid
Fetch a location's corresponding WOEID.

        Args:
            location: (string) a location (e.g. 23454 or Berlin, Germany).

        Returns:
            a string containing the location's corresponding WOEID or None if
                the WOEID could not be found.

        Raises:
            urllib.error.URLError: urllib.request could not open the URL
                (Python 3).
            urllib2.URLError: urllib2 could not open the URL (Python 2).
            xml.etree.ElementTree.ParseError: xml.etree.ElementTree failed to
                parse the XML document.