Method selected_columns

lib/sqlalchemy/sql/selectable.py:7410–7435

A :class:`_expression.ColumnCollection` representing the columns that this SELECT statement or similar construct returns in its result set, not including :class:`_sql.TextClause` constructs. This collection differs from the :attr:`_expression.FromClause.columns`

(
        self,
    )

    @HasMemoized_ro_memoized_attribute
    def selected_columns(
        self,
    ) -> ColumnCollection[str, KeyedColumnElement[Any]]:
        """A :class:`_expression.ColumnCollection`
        representing the columns that
        this SELECT statement or similar construct returns in its result set,
        not including :class:`_sql.TextClause` constructs.

        This collection differs from the :attr:`_expression.FromClause.columns`
        collection of a :class:`_expression.FromClause` in that the columns
        within this collection cannot be directly nested inside another SELECT
        statement; a subquery must be applied first which provides for the
        necessary parenthesization required by SQL.

        For a :class:`_expression.TextualSelect` construct, the collection
        contains the :class:`_expression.ColumnElement` objects that were
        passed to the constructor, typically via the
        :meth:`_expression.TextClause.columns` method.


        .. versionadded:: 1.4

        """
        return WriteableColumnCollection(
            (c.key, c) for c in self.column_args
        ).as_readonly()

    @util.ro_non_memoized_property
    def _all_selected_columns(self) -> _SelectIterable: