def sizeof(*x, seps=True, prec=1):
    """Returns the largest string size of all objects in x, where x is a
    sequence of string or numeric values.
    
    Args:
        *x: The objects to test.
        seps: Whether to include separators (,.) in the size.
        prec: Precision of float values.
    """
    if isinstance(x[0], str):
        return max(len(s) for s in x)
    else:
        if isinstance(x[0], int):
            numlen = len(str(max(x)))
            if seps:
                numlen += (numlen // 3)
        elif isinstance(x[0], float):
            numlen = len(str(round(max(x), prec)))
            if seps:
                numlen += ((numlen - prec - 1) // 3)
        else:
            raise ValueError("Unexpected data type: {}".format(x[0].__class__))
        return numlen