daft.functions.regexp_count#

def regexp_count(
    expr: Expression,
    pattern: str | Expression,
) -> Expression:
    r"""Counts the number of times a regex pattern appears in a string.

    Args:
        expr: The expression to check.
        pattern: The regex pattern to search for as a string or as a column to pick values from.

    Returns:
        Expression: An UInt64 expression with the count of regex matches for each string.

    Examples:
        >>> import daft
        >>> from daft.functions import regexp_count
        >>> df = daft.from_pydict({"x": ["hello world", "foo bar baz", "test123test456"]})
        >>> df.with_column("word_count", regexp_count(df["x"], r"\w+")).collect()
        ╭────────────────┬────────────╮
        │ x              ┆ word_count │
        │ ---            ┆ ---        │
        │ String         ┆ UInt64     │
        ╞════════════════╪════════════╡
        │ hello world    ┆ 2          │
        ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌┤
        │ foo bar baz    ┆ 3          │
        ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌┤
        │ test123test456 ┆ 1          │
        ╰────────────────┴────────────╯
        <BLANKLINE>
        (Showing first 3 of 3 rows)

        >>> df.with_column("digit_count", regexp_count(df["x"], r"\d+")).collect()
        ╭────────────────┬─────────────╮
        │ x              ┆ digit_count │
        │ ---            ┆ ---         │
        │ String         ┆ UInt64      │
        ╞════════════════╪═════════════╡
        │ hello world    ┆ 0           │
        ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┤
        │ foo bar baz    ┆ 0           │
        ├╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌┤
        │ test123test456 ┆ 2           │
        ╰────────────────┴─────────────╯
        <BLANKLINE>
        (Showing first 3 of 3 rows)

    """
    return Expression._call_builtin_scalar_fn("regexp_count", expr, pattern)