def reorder(li: list, a: int, b: int):
    """Reorder li[a] with li[b].

    Args:
        li (list): List to process.
        a (int): Index of first item.
        b (int): Index of second item.

    Returns:
        list: List of reordered items.

    Example:
        >>> reorder([a, b, c], 0, 1)
        <<< [b, a, c]

    """

    li[a], li[b] = li[b], li[a]
    return li