def unique_list_order_preserved(seq):
    """Returns a unique list of items from the sequence
    while preserving original ordering.
    The first occurrence of an item is returned in the new sequence:
    any subsequent occurrences of the same item are ignored.
    """
    seen = set()
    seen_add = seen.add
    return [x for x in seq if not (x in seen or seen_add(x))]