def lists(self, value, key=None):
        """
        Get a list with the values of a given key

        :rtype: list
        """
        results = map(lambda x: x[value], self._items)

        return list(results)
def lists ( self , value , key = None ) : results = map ( lambda x : x [ value ] , self . _items ) return list ( results )
Get a list with the values of a given key

        :rtype: list