retrieve our attributes

def get_attrs(self):
        """ retrieve our attributes """
        self.non_index_axes = getattr(
            self.attrs, 'non_index_axes', None) or []
        self.data_columns = getattr(
            self.attrs, 'data_columns', None) or []
        self.info = getattr(
            self.attrs, 'info', None) or dict()
        self.nan_rep = getattr(self.attrs, 'nan_rep', None)
        self.encoding = _ensure_encoding(
            getattr(self.attrs, 'encoding', None))
        self.errors = _ensure_decoded(getattr(self.attrs, 'errors', 'strict'))
        self.levels = getattr(
            self.attrs, 'levels', None) or []
        self.index_axes = [
            a.infer(self) for a in self.indexables if a.is_an_indexable
        ]
        self.values_axes = [
            a.infer(self) for a in self.indexables if not a.is_an_indexable
        ]
        self.metadata = getattr(
            self.attrs, 'metadata', None) or []