泡菜未保存(或加载?)对象列表变量在\uu init之外__

Python初学者问题。我正在制作一个基于文本的游戏,试图使用pickle保存和加载对象,但列表变量并没有按预期加载。这是我为测试该问题而编写的代码:

import pickle

class my_class(object):
    def __init__(self, x):
        self.x = x
        self.y = [1,2,3]

    a = [4,5,6]
    b = 8

def save(object1):
    print("Game saved")
    pickle_out = open("saveobject1","wb")
    pickle.dump(object1, pickle_out)
    pickle_out.close()

def load():
    print("Loading......")
    pickle_in = open("saveobject1","rb")
    object1 = pickle.load(pickle_in)
    return object1

object1 = my_class(10)

print ("object1.x = " + str(object1.x))
print ("object1.y = " + str(object1.y))
print ("object1.a = " + str(object1.a))
print ("object1.b = " + str(object1.b))
print ("\n")

answer = input("Would you like to save (s) or load (l)?: ")

if answer == "s":
    save(object1)

object1.x = 20
object1.y[2] = 6
object1.a[2] = 12
object1.b = 16

if answer == "l":
    object1 = load()

print ("object1.x = " + str(object1.x))
print ("object1.y = " + str(object1.y))
print ("object1.a = " + str(object1.a))
print ("object1.b = " + str(object1.b))
print ("\n")

列出内的变量 初始化 保存并加载OK(本例中为y),但在外部列出变量 初始化 不要(本例中为a)。但是,外部的非列表变量 初始化 保存并加载。提前感谢您的建议。