def _counties(self):
        """
        Retrieve jurisdictional mappings for a state's counties.

        Returns:
            A list of dictionaries containing jurisdiction metadata, as
            returned by ``jurisdictional_mappings()``.

        """
        try:
            return self._cached_counties
        except __HOLE__:
            county_ocd_re = re.compile(r'ocd-division/country:us/state:' +
                    self.state.lower() + r'/county:[^/]+$')
            self._cached_counties = [m for m in self.jurisdiction_mappings()
                if county_ocd_re.match(m['ocd_id'])]
            return self._cached_counties
dataset/ETHPy150Open openelections/openelections-core/openelex/base/datasource.py/BaseDatasource._counties