Method sort

python/pathway/internals/table.py:2409–2477

Sorts a table by the specified keys. Args: table : pw.Table The table to be sorted. key (ColumnExpression[int | float | datetime | str | bytes]): An expression to sort by. instance : ColumnReference or None

(
        self,
        key: expr.ColumnExpression,
        instance: expr.ColumnExpression | None = None,
    )

    @contextualized_operator
    @check_arg_types
    def sort(
        self,
        key: expr.ColumnExpression,
        instance: expr.ColumnExpression | None = None,
    ) -> Table:
        """
        Sorts a table by the specified keys.

        Args:
            table : pw.Table
                The table to be sorted.
            key (ColumnExpression[int | float | datetime | str | bytes]):
                An expression to sort by.
            instance : ColumnReference or None
                An expression with instance. Rows are sorted within an instance.
                ``prev`` and ``next`` columns will only point to rows that have the same instance.

        Returns:
            pw.Table: The sorted table. Contains two columns: ``prev`` and ``next``, containing the pointers
            to the previous and next rows.

        Example:

        >>> import pathway as pw
        >>> table = pw.debug.table_from_markdown('''
        ... name     | age | score
        ... Alice    | 25  | 80
        ... Bob      | 20  | 90
        ... Charlie  | 30  | 80
        ... ''')
        >>> table = table.with_id_from(pw.this.name)
        >>> table += table.sort(key=pw.this.age)
        >>> pw.debug.compute_and_print(table, include_id=True)
                    | name    | age | score | prev        | next
        ^GBSDEEW... | Alice   | 25  | 80    | ^EDPSSB1... | ^DS9AT95...
        ^EDPSSB1... | Bob     | 20  | 90    |             | ^GBSDEEW...
        ^DS9AT95... | Charlie | 30  | 80    | ^GBSDEEW... |
        >>> table = pw.debug.table_from_markdown('''
        ... name     | age | score
        ... Alice    | 25  | 80
        ... Bob      | 20  | 90
        ... Charlie  | 30  | 80
        ... David    | 35  | 90
        ... Eve      | 15  | 80
        ... ''')
        >>> table = table.with_id_from(pw.this.name)
        >>> table += table.sort(key=pw.this.age, instance=pw.this.score)
        >>> pw.debug.compute_and_print(table, include_id=True)
                    | name    | age | score | prev        | next
        ^GBSDEEW... | Alice   | 25  | 80    | ^T0B95XH... | ^DS9AT95...
        ^EDPSSB1... | Bob     | 20  | 90    |             | ^RT0AZWX...
        ^DS9AT95... | Charlie | 30  | 80    | ^GBSDEEW... |
        ^RT0AZWX... | David   | 35  | 90    | ^EDPSSB1... |
        ^T0B95XH... | Eve     | 15  | 80    |             | ^GBSDEEW...
        """
        instance = clmn.ColumnExpression._wrap(instance)
        self._check_for_disallowed_types(key, instance)
        context = clmn.SortingContext(