Python中，定义类时，怎么在构造方法里将实例对象本身加入到类变量列表中

class Wall:
#存储墙方块列表
wall_list=[]
def init(self):
wall_list.append(self)

class wall:
    wall_list = []
    
    def __init__(self, n):
        self.n = n 
        wall.wall_list.append(self)
    def pri(self):
        print(self.n)
    
    @classmethod
    def show(cls):
        for _ in cls.wall_list:
            print(_.n)
        
w1 = wall('w11')
w2 = wall('w22')

w1.pri()

w2.show()