def islistempty(listvar):
    """
    Checks wether a list has only empty values.
    Empty values are empty strings ("") or None.

    :param list listvar:
    :return: True if empty, False otherwise
    :rtype: bool
    """
    has_empty = True
    empty = '', None
    for item in listvar:
        if item not in empty:
            has_empty = False
    return has_empty
