【python】'Nonetype' object has no attribute ~~の直し方が分からない

前提・実現したいこと

小林　郁夫・佐々木　晃共著の「Pythonによるプログラミング」ｐ160の練習問題6.4に取り組んでいます。最終的にボールがブロックで跳ね返りブロックが消えるアニメーションを作成したいです。しかし、check_blocksのblockが正しく反映されません。自分でも挑戦してみましたが、上手くいきません。ご教授願います。

発生している問題・エラーメッセージ

Traceback (most recent call last):
File "C:\Users\user\Desktop\python\ex06-block.py", line 182, in <module>
box.animate()
File "C:\Users\user\Desktop\python\ex06-block.py", line 162, in animate
self.check_blocks(self.ball,self.block)
File "C:\Users\user\Desktop\python\ex06-block.py", line 145, in check_blocks
if(block.y<ball.y+ball.d/2<block.y+block.h
AttributeError: 'NoneType' object has no attribute 'y'

該当のソースコード

from tkinter import *
from dataclasses import dataclass,field
import time

@dataclass
class Ball:
id:int
x:int
y:int
d:int
vx:int
vy:int
c:str="black"

def move(self):
    self.x=self.x+self.vx
    self.y=self.y+self.vy

def redraw(self):
    d=self.d
    canvas.coords(self.id,self.x,self.y,
              self.x+d,self.y+d)

@dataclass
class Paddle:
id:int
x:int
y:int
w:int
h:int
vy:int = field(init=False,default=0)
c:str="green"

def move(self):
    self.y=self.y+self.vy

def redraw(self):
    canvas.coords(self.id,self.x,self.y,
              self.x+self.w,self.y+self.h)

def set_v(self,v):
    self.vy=v

def stop(self):
    self.vy=0

@dataclass
class Block:
id:int
x:int
y:int
w:int
h:int
c:str

def redraw(self):
    canvas.coords(self.id,self.x,self.y,
              self.x+self.w,self.y+self.h)

def delete(self):
    canvas.delete(self.id)

@dataclass
class Box:
id:int
west:int
north:int
east:int
south:int
ball:Ball
paddle:Paddle
block:Block
paddle_v:int
duration:float

def __init__(self,x,y,w,h,duration):
    self.west,self.north=(x,y)
    self.east,self.south=(x+w,y+h)
    self.ball=None
    self.paddle=None
    self.block=None
    self.blocks=[]
    self.duration=duration
    self.paddle_v=5

def make_ball(self,x,y,d,vx,vy):
    id=canvas.create_oval(x,y,x+d,y+d,
                       fill="black",outline="black")
    return Ball(id,x,y,d,vx,vy)

def make_walls(self):
    canvas.create_rectangle(self.west,self.north,self.east,self.south)

def check_wall(self,ball):
    if ball.x+ball.vx<=self.west or ball.x+ball.d+ball.vx>=self.east:
        ball.vx=-ball.vx
    if ball.y+ball.vy<=self.north or ball.y+ball.d+ball.vy>=self.south:
        ball.vy=-ball.vy

def set_ball(self):
        self.ball=self.make_ball(self.west+10,self.north+10,10,4,2)
    

def make_paddle(self,x,y,w,h,c):
    id=canvas.create_rectangle(x,y,x+w,y+h,
                       fill=c,outline=c)
    return Paddle(id,x,y,w,h)

def check_paddle(self,ball,paddle):
    if(ball.y+ball.d/2>=paddle.y
       and paddle.x<=ball.x+ball.d
       and ball.y+ball.d/2<=paddle.y+paddle.h):
       ball.vx=-ball.vx

def set_paddle(self):
    self.paddle=self.make_paddle(self.east-20,(self.north+self.south)/2-10,
                                 10,20,
                                 "green")

def up_paddle(self,event):
    self.paddle.set_v(-self.paddle_v)

def down_paddle(self,event):
    self.paddle.set_v(self.paddle_v)

def stop_paddle(self,event):
    self.paddle.stop()

def make_block(self,x,y,w,h,c):
    id=canvas.create_rectangle(x,y,x+w,y+h,
                       fill=c,outline=c)
    return Block(id,x,y,w,h,c)


def set_blocks(self,n,s):
    for x in range(n):
        block=self.make_block(self.west+10*x,self.south-30,
                            5,20,"red")
    for x in range(s):
        block=self.make_block(self.west+10*x,self.south-60,
                            5,20,"blue")
        self.blocks.append(block)

def check_blocks(self,ball,block):
    if(block.y<ball.y+ball.d/2<block.y+block.h
       and(block.x<=ball.x<=block.x+block.w
           or block.x<=ball.x+ball.d<=block.x+block.w)):
       ball.vx=-ball.vx
       self.block.delete()
       self.blocks.remove()


def animate(self):
     while True:
        self.ball.move()
        self.paddle.move()
        self.check_wall(self.ball)
        self.check_paddle(self.ball,self.paddle)
        self.ball.redraw()
        self.paddle.redraw()
        for block in self.blocks:
            self.check_blocks(self.ball,self.block)
            self.block.redraw()
        time.sleep(self.duration)
        tk.update()

tk=Tk()
canvas=Canvas(tk,width=800,height=800,bd=0)
canvas.pack()

box=Box(100,100,300,200,0.05)
box.make_walls()
canvas.bind_all("<KeyPress-Up>",box.up_paddle)
canvas.bind_all("<KeyPress-Down>",box.down_paddle)
canvas.bind_all("<KeyRelease-Up>",box.stop_paddle)
canvas.bind_all("<KeyRelease-Down>",box.stop_paddle)
box.set_ball()
box.set_paddle()
box.set_blocks(4,4)
box.animate()