input: Write a function to optimize the given Python program such that it prints each element of the input list on a new line more efficiently. If the input list is empty, the function should return an empty string.
  
  assert optimize_print([1, 2, 3, 4, 5, 6])=='1\n2\n3\n4\n5\n6\n'
  assert optimize_print([])==''
output: def optimize_print(lst):
      if not lst:
          return ''
      return '\n'.join(map(str, lst)) + '\n'