code: def __remove_duplicates(self, _other):
          
          if not isinstance(_other, type(self)) \
             and not isinstance(_other, type(list)) \
             and not isinstance(_other, type([])):
              other = [_other]
          else:
              other = list(_other)
  
          # remove items already in self
          newother = []
          for i in range(0, len(other)):
              item = other.pop(0)
              if not list.__contains__(self, item):
                  newother.append(item)
  
          # remove duplicate items in other
          other = []
          if newother != []:
              other.append(newother[0])
              for i in range(1, len(newother)):
                  item = newother.pop()
                  if not other.__contains__(item):
                      other.append(item)
          return other
docs: Remove from other items already in list.