code: def unique(lst):
      
      nl = []
      [(nl.append(e) if type(e) is not list else nl.extend(e)) \
       for e in lst if e not in nl]
      return nl
docs: Unique with keeping sort/order
          ["a", "c", "b", "c", "c", ["d", "e"]]
  
      Results in
          ["a", "c", "b", "d", "e"]