def listDifference(total, used):
    """
    Return the remaining part of "total" after removing elements in "used". Each element will be removed only once.

    Parameters
    ----------
    total : list of any
        The original list from which we want to remove some elements.
    used : list of any
        The elements we want to remove from total.

    Returns
    -------
    list of any
        The list total after removing elements in used.
    """
    ret = list(total)
    for x in used:
        ret.remove(x)
    return ret