input: Write a function to delete all duplicates in a given list of numbers. The function should return a new list with all unique elements in the same order as they appear in the input list. If the input list is empty, the function should 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, 4, 4, 4]) == [4]
  assert deleteDuplicates([5, 6, 7, 8]) == [5, 6, 7, 8]
  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