Class OrderByList

lib/sqlalchemy/sql/elements.py:2937–3002

Describe a list of clauses that will be comma separated to nest within an ORDER BY. .. versionadded:: 2.1

class OrderByList(
    roles.OrderByRole,
    operators.OrderingOperators,
    DQLDMLClauseElement,
):
    """Describe a list of clauses that will be comma separated to nest
    within an ORDER BY.

    .. versionadded:: 2.1

    """

    __visit_name__ = "order_by_list"

    _traverse_internals: _TraverseInternalsType = [
        ("clauses", InternalTraversal.dp_clauseelement_tuple),
    ]

    clauses: List[ColumnElement[Any]]

    def __init__(
        self,
        clauses: Iterable[Union[OrderByList, _ColumnExpressionArgument[Any]]],
    ):
        text_converter_role: Type[roles.SQLRole] = roles.ByOfRole
        self._text_converter_role = text_converter_role

        self.clauses = [
            coercions.expect(
                text_converter_role, clause, apply_propagate_attrs=self
            )
            for clause in clauses
        ]

    def __iter__(self) -> Iterator[ColumnElement[Any]]:
        return iter(self.clauses)

    def __len__(self) -> int:
        return len(self.clauses)

    @property
    def _select_iterable(self) -> _SelectIterable:
        return itertools.chain.from_iterable(
            [elem._select_iterable for elem in self.clauses]
        )

    @util.ro_non_memoized_property
    def _from_objects(self) -> List[FromClause]:
        return list(itertools.chain(*[c._from_objects for c in self.clauses]))

    def self_group(
        self, against: Optional[OperatorType] = None
    ) -> Union[Self, Grouping[Any]]:
        return self

    def desc(self) -> OrderByList:
        return OrderByList([e.desc() for e in self.clauses])