Function col

python/ray/data/expressions.py:2006–2030

Reference an existing column by name. This is the primary way to reference columns in expressions. The returned expression will extract values from the specified column when evaluated. Args: name: The name of the column to reference Returns: A ColumnExpr t

(name: str)

@PublicAPI(stability="beta")
def col(name: str) -> ColumnExpr:
    """
    Reference an existing column by name.

    This is the primary way to reference columns in expressions.
    The returned expression will extract values from the specified
    column when evaluated.

    Args:
        name: The name of the column to reference

    Returns:
        A ColumnExpr that references the specified column

    Example:
        >>> from ray.data.expressions import col
        >>> # Reference columns in an expression
        >>> expr = col("price") * col("quantity")
        >>>
        >>> # Use with Dataset.with_column()
        >>> import ray
        >>> ds = ray.data.from_items([{"price": 10, "quantity": 2}])
        >>> ds = ds.with_column("total", col("price") * col("quantity"))
    """
    return ColumnExpr(name)


@PublicAPI(stability="beta")