input: 
  def removeDuplicates(arr):
      result = [] 
      
      # traverse for all elements 
      for i in arr: 
      
          # check if exists in result 
          if i not in result: 
              result.append(i) 
      
      # return result 
      return result
  
  # Example usage:
  # >>> removeDuplicates(['a', 'b', 'a', 'c', 'c', 'd'])
  # ['a', 'b', 'c', 'd']
  
output:     return result