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

class my_linked_list:
  def __init__(self):
    self.head = None
    self.last_node = None

  def add_value(self, my_data):
    if self.last_node is None:
      self.head = Node(my_data)
      self.last_node = self.head
    else:
      self.last_node.next = Node(my_data)
      self.last_node = self.last_node.next

  def print_it(self):
    curr = self.head
    while curr:
      print(curr.data)
      curr = curr.next

  def count_val(self, key):
    curr = self.head
    my_count = 0
    while curr:
      if curr.data == key:
        my_count = my_count + 1
      curr = curr.next
    return my_count

my_instance = my_linked_list()
my_list = [56, 43, 70, 67, 89, 91, 70, 23, 46, 70]
for elem in my_list:
  my_instance.add_value(elem)
print("链表包含以下元素：")
my_instance.print_it()

key_val = int(input('输入数据项：'))
count_val = my_instance.count_val(key_val)
print('{0}在列表中出现了{1}次。'.format(key_val, count_val))

链表包含以下元素：
56
43
70
67
89
91
70
23
46
70
输入数据项：70
70在列表中出现了3次。