def stable_unique(items):
    """
    Return a copy of ``items`` without duplicates.  The order of other items is
    unchanged.

      >>> stable_unique([1,4,6,4,6,5,7])
      [1, 4, 6, 5, 7]
    """
    result = []
    seen = set()
    for item in items:
        if item in seen:
            continue
        seen.add(item)
        result.append(item)
    return result