input: Write a function to remove all duplicates from a given list of numbers and return the list in the same order as the first occurrences of each number. 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, 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