Function _optional

python/pathway/stdlib/utils/col.py:137–144

(
            col: pw.ColumnExpression,
            op: Callable[[pw.ColumnExpression], pw.ColumnExpression],
        )

        result: pw.ColumnExpression

        def _optional(
            col: pw.ColumnExpression,
            op: Callable[[pw.ColumnExpression], pw.ColumnExpression],
        ) -> pw.ColumnExpression:
            if is_optional:
                return pw.if_else(col == pw.Json.NULL, None, op(col))
            else:
                return op(col)

        match _type:
            case dt.JSON: