input: Write a function to delete all duplicates in a given list of numbers. If the given list is empty then return an empty list.
  def deleteDuplicates(list): 
      final_list = [] 
      for num in list: 
          if num not in final_list: 
              final_list.append(num) 
      return final_list
  assert deleteDuplicates([1, 2, 3, 2, 1])==[1, 2, 3]
  assert deleteDuplicates([4, 5, 5, 6, 4])==[4, 5, 6]
  assert deleteDuplicates([7, 8, 9, 7, 8])==[7, 8, 9]
  assert deleteDuplicates([])==[]
output: def deleteDuplicates(list): 
      final_list = [] 
      for num in list: 
          if num not in final_list: 
              final_list.append(num) 
      return final_list