def _transform_fast(self, result, obj, func_nm):
<EOL>cast = self._transform_should_cast(func_nm)<EOL>ids, _, ngroup = self.grouper.group_info<EOL>output = []<EOL>for i, _ in enumerate(result.columns):<EOL><INDENT>res = algorithms.take_1d(result.iloc[:, i].values, ids)<EOL>if cast:<EOL><INDENT>res = self._try_cast(res, obj.iloc[:, i])<EOL><DEDENT>output.append(res)<EOL><DEDENT>return DataFrame._from_arrays(output, columns=result.columns,<EOL>index=obj.index)<EOL>
Fast transform path for aggregations