def groupby(self, by=None, axis=0, level=None, as_index=True, sort=True, group_keys=True, squeeze=False): from pandas_ml.core.groupby import groupby if level is None and by is None: raise TypeError("You have to supply one of 'by' and 'level'") axis = self._get_axis_number(axis) return groupby(self, by=by, axis=axis, level=level, as_index=as_index, sort=sort, group_keys=group_keys, squeeze=squeeze)