Method lower

python/pathway/internals/expressions/string.py:33–72

Returns a lowercase copy of a string. Returns: Lowercase string Example: >>> import pathway as pw >>> table = pw.debug.table_from_markdown( ... ''' ... | name ... 1 | Alice ... 2 | Bob ... 3 | CA

(self)

        self._expression = expression

    def lower(self) -> expr.ColumnExpression:
        """Returns a lowercase copy of a string.

        Returns:
            Lowercase string

        Example:

        >>> import pathway as pw
        >>> table = pw.debug.table_from_markdown(
        ...     '''
        ...      | name
        ...    1 | Alice
        ...    2 | Bob
        ...    3 | CAROLE
        ...    4 | david
        ... '''
        ... )
        >>> table += table.select(name_lower=table.name.str.lower())
        >>> pw.debug.compute_and_print(table, include_id=False)
        name   | name_lower
        Alice  | alice
        Bob    | bob
        CAROLE | carole
        david  | david
        """

        return expr.MethodCallExpression(
            (
                (
                    dt.STR,
                    dt.STR,
                    lambda x: api.Expression.apply(
                        str.lower, x, dtype=dt.STR.to_engine()
                    ),
                ),
            ),
            "str.lower",
            self._expression,
        )

    def upper(self) -> expr.ColumnExpression:
        """Returns a uppercase copy of a string.