code: def unique(lst):
      
      lst = lst[:]
      unique_lst = []
  
      # Cycle through the list and add each value to the unique list only once.
      for item in lst:
          if unique_lst.count(item) <= 0:
              unique_lst.append(item)
              
      # Return the list with all redundant values removed.
      return unique_lst
docs: Returns a list made up of the unique values found in lst.  i.e., it
      removes the redundant values in lst.