Method count

python/pathway/internals/expressions/string.py:473–524

Returns the number of non-overlapping occurrences of substring sub in the range [start, end). Optional arguments start and end are interpreted as in slice notation. Example: >>> import pathway as pw >>> table = pw.debug.table_from_markdown( ... '''

(
        self,
        sub: expr.ColumnExpression | str,
        start: expr.ColumnExpression | int | None = None,
        end: expr.ColumnExpression | int | None = None,
    )

        )

    def count(
        self,
        sub: expr.ColumnExpression | str,
        start: expr.ColumnExpression | int | None = None,
        end: expr.ColumnExpression | int | None = None,
    ) -> expr.ColumnExpression:
        """Returns the number of non-overlapping occurrences of substring sub in the range [start, end).
        Optional arguments start and end are interpreted as in slice notation.


        Example:

        >>> import pathway as pw
        >>> table = pw.debug.table_from_markdown(
        ...     '''
        ...      | name
        ...    1 | Alice
        ...    2 | Hello
        ...    3 | World
        ...    4 | Zoo
        ... '''
        ... )
        >>> table += table.select(count=table.name.str.count("o"))
        >>> pw.debug.compute_and_print(table, include_id=False)
        name  | count
        Alice | 0
        Hello | 1
        World | 1
        Zoo   | 2
        """

        return expr.MethodCallExpression(
            (
                (
                    (
                        dt.STR,
                        dt.STR,
                        dt.Optional(dt.INT),
                        dt.Optional(dt.INT),
                    ),
                    dt.INT,
                    lambda *args: api.Expression.apply(
                        str.count, *args, dtype=dt.INT.to_engine()
                    ),
                ),
            ),
            "str.count",
            self._expression,
            sub,
            start,
            end,
        )

    def find(
        self,