input: Write a function to create a loop in Python that prints each item of the given list with a specific message. If the list is empty, print "The list is empty."
  assert print_items(['A', 'B', 'C', 'D'])
  assert print_items([])
output: def print_items(lst):
      if not lst:
          print("The list is empty.")
      else:
          for item in lst:
              print(item)