不打印结果链表-Python

Question

问题是（来自：“破解编码访谈”）：

  

您有两个由链表表示的数字，其中每个节点   包含一个数字。这些数字以相反的顺序存储，例如   1的数字位于列表的开头。写一个函数   将两个数字相加，然后将总和作为链表返回。
  例子
  输入：（3-> 1-> 5）+（5-> 9-> 2）
  输出：8-> 0-> 8

我的代码是：

#Define node and convenience methods
class Node(object):
  def __init__(self,data = None, next_node = None):
    self.data = data
    self.next_node = next_node
  def get_data(self):
    return self.data
  def get_next(self):
    return self.next_node
  def set_next(self, new_next):
    self.next_node = new_next

#Make first linked list
class LinkedList1(object):
  def __init__(self, head = None):
    self.head = head
  def insert(self, data):
    new_node = Node(data)
    new_node.set_next(self.head)
    self.head = new_node
  #iterate through the list and save a list of the numbers
  def iterate(self):
    current = self.head
    list1 = []
    while current:
      list1.append(current.get_data())
      current = current.get_next()
    return list1

#Define second linked list
class LinkedList2(object):
  def __init__(self, head = None):
    self.head = head
  def insert(self, data):
    new_node = Node(data)
    new_node.set_next(self.head)
    self.head = new_node
  #iterate through the list and save a list of the numbers
  def iterate(self):
    current = self.head
    list2 = []
    while current:
      list2.append(current.get_data())
      current = current.get_next()
    return list2

object1 = LinkedList1()
object2 = LinkedList2()

#Define resulting linked list and print it
class New(object):
  def __init__(self,head = None):
    self.head = head
  def linked_list(self, new_list1):
    for i in new_list1:
      new_node = Node(i)
      new_node.set_next(self.head)
      self.head = new_node
  def printing(self):
    current = self.head
    while current:
      print(current.get_data(), end = " ")
      current = current.get_next()
    return

no1 = object1.iterate()
no2 = object2.iterate()
new_list = []

#Calculate sum recursively
def sum_calc(carry):
  sum1 = 0
  while no1 and no2:
    sum1 = no1.pop(0) + no2.pop(0) + carry
    if sum1 > 10:
      new_list.append(sum1 % 10)
      sum_calc(1)
    else:
      new_list.append(sum1)
      sum_calc(0)
  #If any elements left in no1
  if no1:
    new_list.extend(no1)
  #If any elements left in no2
  elif no2:
    new_list.extend(no2)
  else:
    return new_list

object3 = New()  
passing = []

while True:
  print("1.Insert in list 1")
  print("2.Insert in list 2")
  print("3.Sum")
  print("4.New List of sum")
  print("5.Exit")
  option = (int)(input("option: "))
  if option == 1:
    data = (int)(input("Data: "))
    object1.insert(data)
  elif option == 2:
    data = (int)(input("Data: "))
    object2.insert(data)
  elif option == 3:
    #Initial carry = 0 when adding unit's digits
    passing = sum_calc(0)
  elif option == 4:
    object3.linked_list(passing)
    object3.printing()
    print()
  else:
    break

但是，每当option ==4都不打印任何内容时，它会进入while循环的下一个迭代。

我知道这不是最佳解决方案，但是任何人都可以帮助指出算法思维中的错误或任何错误吗？谢谢！