code: def geodist(self, name, place1, place2, unit=None):
          
          pieces = [name, place1, place2]
          if unit and unit not in ('m', 'km', 'mi', 'ft'):
              raise DataError("GEODIST invalid unit")
          elif unit:
              pieces.append(unit)
          return self.execute_command('GEODIST', *pieces)
docs: Return the distance between ``place1`` and ``place2`` members of the
          ``name`` key.
          The units must be one of the following : m, km mi, ft. By default
          meters are used.