代码没有任何问题，但是一直在报错，不知道是什么问题

我没事写了个代码，一运行就一直报错
代码如下

# -*- coding:utf-8 -*-
import pygame as p
import sys as s

result = input("Welcome!If you want to play the game,please enter 1,if you want to know the writer,please enter 2 ,if you want to exit,please enter 3,if you want to experience other functions,please enter 4")
if result == 1:
    def game():
        p.init()
        size = width,height = 500,400
        screen = p.display.set_mode(size)
        color = (0,0,0)
        ball = p.image.load("ball(1).jpg")
        ballrect = ball.get_rect()

        speed = [5,5]
        clock = p.time.Clock()
        while True:
            clock.tick(60)
            for event in p.event.get():
                if event.type == p.QUIT:
                    s.exit()

            ballrect = ballrect.move(speed)
            if ballrect.left < 0 or ballrect.right > width:
                speed[0] = -speed[0]
            if ballrect.top < 0 or ballrect.bottom > height:
                speed[1] = -speed[1]

            screen.fill(color)
            screen.blit(ball,ballrect)
            p.display.flip()

        p.quit()
    game()
if result == 2:
    print("Writer:ekl      All Rights Reserved.")
if result == 3:
    exit()
else:
    result = input("the functions are developmenting and they're dangerous,Sure to use it?(Yes or No)")
    if result == "Yes":                                                                                                                   #有问题
        result = input("Plase choose the experiences   1.command    2.games      3.exit           4..........（only enter the numbers)")
    if result == 1:
        print("please write the command")
        result = input("e.g:exit()")
    if result == "exit()":
        exit()
    if result == "game()":
        game()
    else:
        print("the command is wrong,the program will exit")
        exit()
    if result == 2:
        pass
    if result == 3:
        exit()
    else:
        pass
    if result == "No":                                                                                                                  #同样有问题
        exit()

运行结果：

C:\Python27\python.exe C:/Users/Administrator/Desktop/pythonProject5/add.py
pygame 2.0.3 (SDL 2.0.16, Python 2.7.18)
Hello from the pygame community. https://www.pygame.org/contribute.html
Welcome!If you want to play the game,please enter 1,if you want to know the writer,please enter 2 ,if you want to exit,please enter 3,if you want to experience other functions,please enter 44
the functions are developmenting and they're dangerous,Sure to use it?(Yes or No)No
Traceback (most recent call last):
  File "C:/Users/Administrator/Desktop/pythonProject5/add.py", line 40, in <module>
    result = input("the functions are developmenting and they're dangerous,Sure to use it?(Yes or No)")
  File "<string>", line 1, in <module>
NameError: name 'No' is not defined

Process finished with exit code 1

一直找不到问题

input()讀取的值爲str類型, 你if的條件判斷好幾處錯誤, 應是result=='2'這樣的形式,
你先修改這个試試