class Node:
   def __init__(self, my_data):
      self.prev = None
      self.data = my_data
      self.next = None

class double_list:
   def __init__(self):
      self.head = None
      self.tail = None

   def add_data_at_end(self, my_data):
      new_node = Node(my_data)
      if(self.head == None):
         self.head = self.tail = new_node
         self.head.previous = None
         self.tail.next = None
      else:
         self.tail.next = new_node
         new_node.previous = self.tail
         self.tail = new_node
         self.tail.next = None

   def print_it(self):
      curr = self.head
      if (self.head == None):
         print("双向链表是空的")
         return
      print("双向链表中的节点为：")
      while curr != None:
         print(curr.data)
         curr = curr.next

my_instance = double_list()
print("正在把元素添加到双向链表的末尾")
my_instance.add_data_at_end(10)
my_instance.print_it()
my_instance.add_data_at_end(24)
my_instance.print_it()
my_instance.add_data_at_end(54)
my_instance.print_it()
my_instance.add_data_at_end(77)
my_instance.print_it()
my_instance.add_data_at_end(92)
my_instance.print_it()

正在把元素添加到双向链表的末尾
双向链表中的节点为：
10
双向链表中的节点为：
10
24
双向链表中的节点为：
10
24
54
双向链表中的节点为：
10
24
54
77
双向链表中的节点为：
10
24
54
77
92