daft.functions.columns_max#

def columns_max(*exprs: Expression | str) -> Expression:
    """Find the maximum value across columns.

    Args:
        exprs: The columns to find the maximum of.

    Examples:
        >>> import daft
        >>> from daft.functions import columns_max
        >>> df = daft.from_pydict({"a": [1, 2, 3], "b": [4, 5, 6]})
        >>> df = df.with_column("max", columns_max("a", "b"))
        >>> df.show()
        ╭───────┬───────┬───────╮
        │ a     ┆ b     ┆ max   │
        │ ---   ┆ ---   ┆ ---   │
        │ Int64 ┆ Int64 ┆ Int64 │
        ╞═══════╪═══════╪═══════╡
        │ 1     ┆ 4     ┆ 4     │
        ├╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┤
        │ 2     ┆ 5     ┆ 5     │
        ├╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┤
        │ 3     ┆ 6     ┆ 6     │
        ╰───────┴───────┴───────╯
        <BLANKLINE>
        (Showing first 3 of 3 rows)
    """
    if not exprs:
        raise ValueError("columns_max requires at least one expression")
    exprs_list = [col(e) if isinstance(e, str) else e for e in exprs]
    return to_list(*exprs_list).list_max().alias("columns_max")