def set_tuple_item(tup, index, item):
    """Tuples are immutable. Therefore, this method provides item assigned to a
    copy of the initial tuple.

    Args:
        tup: The tuple, that should be mutated.
        index: The index of the item in tup that should be mutated.
        item: The value that should be assigned to tup[index].

    Returns:
        A copy of tup, but the value of one item has changed in the desired
        way.
    """
    lst = list(tup)
    lst[index] = item
    return tuple(lst)