def _val_is_numeric(x: Any) -> bool:
    """
    Determine whether a scalar value is numeric (i.e., either an integer or a float).
    """

    # If a list then signal a failure
    if isinstance(x, list):
        raise ValueError("The input cannot be a list. It must be a single value.")

    return isinstance(x, (int, float))

    Determine whether a scalar value is numeric (i.e., either an integer or a float).
    
great_tables/_utils_nanoplots.py