【Python】《python从入门到实践》《外星人入侵》中捕获鼠标左键右键的操作失败

Question

问题代码：if event.key == pygame.K_RIGHT:
elif event.key == pygame.K_LEFT:

import sys
import pygame

pygame.KEYDOWN=1026

def check_events(spaceship):
    for event in pygame.event.get():  
        # print(pygame.K_RIGHT,pygame.K_LEFT,event.type,pygame.KEYDOWN)
        if event.type==pygame.QUIT:  
            sys.exit()
        elif event.type==pygame.KEYDOWN:
            if event.key == pygame.K_RIGHT:
                spaceship.rect.centerx+=100
            elif event.key == pygame.K_LEFT:
                spaceship.rect.centerx-=100

def update_screen(ai_sett,screen,spaceship):
    screen.fill(ai_sett.bg_color)
    spaceship.blitme()

import pygame
import sett
import ship
import game_func as gf
def run_game():
    pygame.init()

    ai_sett=sett.Settings()
    screen=pygame.display.set_mode((ai_sett.screen_width,ai_sett.screen_height))
    spaceship=ship.Ship(screen)

    pygame.display.set_caption("Alien invasion")

    while True:
        gf.check_events(spaceship)
        gf.update_screen(ai_sett,screen,spaceship)
        pygame.display.flip()

run_game()

import pygame

class Ship():
    def __init__(self,screen):
        self.screen=screen
        self.image=pygame.image.load("spaceship.bmp")
        self.rect=self.image.get_rect()
        self.screen_rect=screen.get_rect()

        self.rect.centery=self.screen_rect.centery
        self.rect.centerx=self.screen_rect.centerx
        self.rect.bottom=self.screen_rect.bottom
    def blitme(self):
        self.screen.blit(self.image,self.rect)

class Settings():
    def __init__(self):
        self.screen_width=1400
        self.screen_height=800
        self.bg_color=(148,214,246)

报错 'Event' object has no attribute 'key'
本人的疑惑：1.type，keydown,k_right等值是怎么赋值的，在我为给keydown赋值之前点一下鼠标后返回的type值是不等于keydown的
2.本人认为event.key()应该是函数库里的变量来捕捉鼠标操作的，就是鼠标一点它就会返回一个值，但为何实际上我一点鼠标它就报错