Method _validate_expression

python/pathway/internals/table.py:2506–2515

(self, expression: expr.ColumnExpression)

        return self._table_with_context(context)

    def _validate_expression(self, expression: expr.ColumnExpression):
        for dep in expression._dependencies_above_reducer():
            if self._universe != dep._column.universe:
                raise ValueError(
                    f"You cannot use {dep.to_column_expression()} in this context."
                    + " Its universe is different than the universe of the table the method"
                    + " was called on. You can use <table1>.with_universe_of(<table2>)"
                    + " to assign universe of <table2> to <table1> if you're sure their"
                    + " sets of keys are equal."
                )

    def _check_for_disallowed_types(self, *expressions: expr.ColumnExpression):
        for expression in expressions: