daft.functions.columns_mean#

def columns_mean(*exprs: Expression | str) -> Expression:
    """Average values across columns. Akin to `columns_avg`.

    Args:
        exprs: The columns to average.

    Examples:
        >>> import daft
        >>> from daft.functions import columns_mean
        >>> df = daft.from_pydict({"a": [1, 2, 3], "b": [4, 5, 6]})
        >>> df = df.with_column("mean", columns_mean("a", "b"))
        >>> df.show()
        ╭───────┬───────┬─────────╮
        │ a     ┆ b     ┆ mean    │
        │ ---   ┆ ---   ┆ ---     │
        │ Int64 ┆ Int64 ┆ Float64 │
        ╞═══════╪═══════╪═════════╡
        │ 1     ┆ 4     ┆ 2.5     │
        ├╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
        │ 2     ┆ 5     ┆ 3.5     │
        ├╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┤
        │ 3     ┆ 6     ┆ 4.5     │
        ╰───────┴───────┴─────────╯
        <BLANKLINE>
        (Showing first 3 of 3 rows)
    """
    if not exprs:
        raise ValueError("columns_mean 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_mean().alias("columns_mean")