有人能解释一下为什么当我的背景出现时,我的骑士不会出现吗

所以我将我的战斗系统代码导入到菜单播放屏幕的while循环中,该代码处理所有图像和战斗系统的代码,但由于某种原因,我的背景显示在与骑士相同的battle_systems文件中,但我的骑士没有

这是所有内容都要导入到的菜单代码

import sys

import pygame 

import Battle_system 
from button import Button

pygame.init()

SCREEN = pygame.display.set_mode((1280, 720))
pygame.display.set_caption("Menu")

BG = pygame.image.load(r"C:\Users\olive\Desktop\Programming project\rpg\Menu\Background1.png")
SURFACE = pygame.image.load(r'C:\Users\olive\Desktop\Programming project\rpg\Menu\surface.png')


def get_font(size):  # Returns Press-Start-2P in the desired size
    return pygame.font.Font(r"C:\Users\olive\Desktop\Programming project\rpg\Menu\font.ttf", size)


def play():
    while True:
        PLAY_MOUSE_POS: object = pygame.mouse.get_pos()

        #draw background
        PLAY_TEXT = get_font(45).render("This is the PLAY screen.", True, "White")
        PLAY_RECT = PLAY_TEXT.get_rect(center=(640, 260))
        SCREEN.blit(SURFACE, PLAY_RECT)
        Battle_system.draw_bg()
        Battle_system.draw_panel() 
        

        #draw characters
        Battle_system.knight.draw
        

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                sys.exit()

        pygame.display.update()

def new_func():
    Battle_system.knight.draw


def options():
    while True:
        OPTIONS_MOUSE_POS = pygame.mouse.get_pos()

        SCREEN.fill("white")

        OPTIONS_TEXT = get_font(45).render("This is the OPTIONS screen.", True, "Black")
        OPTIONS_RECT = OPTIONS_TEXT.get_rect(center=(640, 260))
        SCREEN.blit(OPTIONS_TEXT, OPTIONS_RECT)

        OPTIONS_BACK = Button(image=None, pos=(640, 460),
                              text_input="BACK", font=get_font(75), base_color="Black", hovering_color="Green")

        OPTIONS_BACK.changeColor(OPTIONS_MOUSE_POS)
        OPTIONS_BACK.update(SCREEN)

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                sys.exit()
            if event.type == pygame.MOUSEBUTTONDOWN:
                if OPTIONS_BACK.checkForInput(OPTIONS_MOUSE_POS):
                    main_menu()

        pygame.display.update()


def main_menu():
    while True:
        SCREEN.blit(BG, (0, 0))

        MENU_MOUSE_POS = pygame.mouse.get_pos()

        MENU_TEXT = get_font(100).render("MAIN MENU", True, "#b68f40")
        MENU_RECT = MENU_TEXT.get_rect(center=(640, 100))

        PLAY_BUTTON = Button(
            image=pygame.image.load(r"C:\Users\olive\Desktop\Programming project\rpg\Menu\Play Rect.png"),
            pos=(640, 250),
            text_input="PLAY", font=get_font(75), base_color="#d7fcd4", hovering_color="White")
        OPTIONS_BUTTON = Button(
            image=pygame.image.load(r"C:\Users\olive\Desktop\Programming project\rpg\Menu\Options Rect.png"),
            pos=(640, 400),
            text_input="OPTIONS", font=get_font(75), base_color="#d7fcd4", hovering_color="White")
        QUIT_BUTTON = Button(
            image=pygame.image.load(r"C:\Users\olive\Desktop\Programming project\rpg\Menu\Quit Rect.png"),
            pos=(640, 550),
            text_input="QUIT", font=get_font(75), base_color="#d7fcd4", hovering_color="White")

        SCREEN.blit(MENU_TEXT, MENU_RECT)

        for button in [PLAY_BUTTON, OPTIONS_BUTTON, QUIT_BUTTON]:
            button.changeColor(MENU_MOUSE_POS)
            button.update(SCREEN)

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                sys.exit()
            if event.type == pygame.MOUSEBUTTONDOWN:
                if PLAY_BUTTON.checkForInput(MENU_MOUSE_POS):
                    play()
                if OPTIONS_BUTTON.checkForInput(MENU_MOUSE_POS):
                    options()
                if QUIT_BUTTON.checkForInput(MENU_MOUSE_POS):
                    pygame.quit()
                    sys.exit()

        pygame.display.update()


main_menu()

这就是战斗系统代码本身

import pygame,sys,random

pygame.init()

SCREEN = pygame.display.set_mode((1280, 720))
pygame.display.set_caption("Battle")


clock = pygame.time.Clock()
fps = 60







#load images
#background image
GBG = pygame.image.load(r'C:\Users\olive\Desktop\Programming project\rpg\setting\Background.png')
#panel image
PNL = pygame.image.load(r'C:\Users\olive\Desktop\Programming project\rpg\setting\panel.png')




#function for drawing background
def draw_bg():
    SCREEN.blit(GBG, (0, 0))


#function for drawing panel
def draw_panel():
    SCREEN.blit(PNL, (0, 500))



#fighter class
class Fighter():
    def __init__(self, x, y, name, max_hp, strength, potions):
        self.name = name
        self.max_hp = max_hp
        self.hp = max_hp
        self.strength = strength
        self.start_potions = potions
        self.potions = potions
        self.alive = True
        img = pygame.image.load(f'rpg/{self.name}/idle/0.png')
        self.image = pygame.transform.scale(img, (img.get_width() * 3, img.get_height() * 3))
        self.rect = self.image.get_rect()
        self.rect.center = (x, y)


    def draw(self):
        SCREEN.blit(self.image, self.rect)


knight = Fighter(200, 260, 'Lothric', 30, 10, 3)
slime1 = Fighter(550, 270, 'Slime', 20, 6, 1)
slime2 = Fighter(700, 270, 'Slime', 20, 6, 1)

slime_list = []
slime_list.append(slime1)
slime_list.append(slime2)

整个代码运行正常,没有任何错误,但骑士没有出现,我只是一个执着于答案的人