def place_mappings(self, filename=None):
        try:
            return self._cached_place_mappings
        except __HOLE__:
            if filename is None:
                filename = join(self.mappings_dir, self.state + '_places.csv')

            with open(filename, 'rU') as csvfile:
                reader = unicodecsv.DictReader(csvfile)
                self._cached_place_mappings = [row for row in reader]

            return self._cached_place_mappings
dataset/ETHPy150Open openelections/openelections-core/openelex/base/datasource.py/BaseDatasource.place_mappings