input: Write a function to print the unique elements of a given list. The function should take a list as input and print each unique element exactly once. If the list is empty, it should print nothing.
  def print_unique(my_list):
      seen = set()
      for x in my_list:
          if x not in seen:
              print(x)
              seen.add(x)
output: def print_unique(my_list):
      seen = set()
      for x in my_list:
          if x not in seen:
              print(x)
              seen.add(x)