编写python时 使用pygame.sprite.Sprite发生了一些问题 求助

"""
 Snake Game template, using classes.
 
 Derived from:
 Sample Python/Pygame Programs
 Simpson College Computer Science
 http://programarcadegames.com/
 http://simpson.edu/computer-science/
 
"""
 
import pygame
import random
 
# --- Globals ---
# Colors
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
 
# Screen size
height = 600
width = 600
 
# Margin between each segment
segment_margin = 3
 
# Set the width and height of each snake segment
segment_width = min(height, width) / 40 - segment_margin
segment_height = min(height, width) / 40 - segment_margin
 
# Set initial speed
x_change = segment_width + segment_margin
y_change = 0
position=[ i for i in range(0, 600, 15)]

class Snake():
    """ Class to represent one snake. """

    # Constructor
    def __init__(self):

        # Food().__init__()
        # Sfoodlists = Food().foodlists
        # Sfoodlist = Food().foodlist

        self.segments = []
        self.spriteslist = pygame.sprite.Group()
        for i in range(15):
            x = (segment_width + segment_margin) * 30 - (segment_width + segment_margin) * i
            y = (segment_height + segment_margin) * 2
            segment = Segment(x, y)
            self.segments.append(segment)
            self.spriteslist.add(segment)
            
    def move(self):
        # Figure out where new segment will be
        x = self.segments[0].rect.x + x_change
        y = self.segments[0].rect.y + y_change
        
        # Don't move off the screen
        # At the moment a potential move off the screen means nothing happens, but it should end the game
        if 0 <= x <= width - segment_width and 0 <= y <= height - segment_height:  
        
        # Insert new segment into the list
            segment = Segment(x, y)
            self.segments.insert(0, segment)
            self.spriteslist.add(segment)
        # Get rid of last segment of the snake
        # .pop() command removes last item in list
            old_segment = self.segments.pop()
            self.spriteslist.remove(old_segment)
        self.eat()



    def eat(self):
        print(self.segments[0].rect,"1")
        hit_list = pygame.sprite.spritecollide(self.segments[0], Food().foodlist,True)
        # print(self.Sfoodlist)
        print(Food().foodlists[0].rect,"2")
        # if hit_list  != []:
        #     newfoodlists = Food().foodlists.remove(hit_list[0])
        #     print(newfoodlists)
        #     for w in newfoodlists:
        #         Food_item(w)








class Segment(pygame.sprite.Sprite):
    """ Class to represent one segment of a snake. """

    # Constructor
    def __init__(self, x, y):
        # Call the parent's constructor
        super().__init__()
 
        # Set height, width
        self.image = pygame.Surface([segment_width, segment_height])
        self.image.fill(WHITE)
 
        # Set top-left corner of the bounding rectangle to be the passed-in location.
        self.rect = self.image.get_rect()
        self.rect.x = x
        self.rect.y = y

class Food():
    def __init__(self):
        self.foodlists = []
        self.foodlist = pygame.sprite.Group()

        for i in range(1):
            x = random.choice([i for i in range(0, 600, 15)])
            y = random.choice([i for i in range(0, 600, 15)])
            fooditem = Food_item(x, y)
            self.foodlists.append(fooditem)
            self.foodlist.add(fooditem)

class Food_item(pygame.sprite.Sprite):
    def __init__(self, fx, fy):
        # Call the parent's constructor
        super().__init__()
        # Set height, width
        self.image = pygame.Surface([segment_width, segment_height])
        self.image.fill(RED)

        # Set top-left corner of the bounding rectangle to be the passed-in location.
        self.rect = self.image.get_rect()
        self.rect.x = fx
        self.rect.y = fy




# class Food_item(pygame.sprite.Sprite):

 
# Call this function so the Pygame library can initialize itself
pygame.init()
 
# Create a 600x600 sized screen
screen = pygame.display.set_mode([width, height])
 
# Set the title of the window
pygame.display.set_caption('Snake Game')
 
# Create an initial snake
my_snake = Snake()
food = Food()
# print(food.foodlists[0].rect)
# S = Segment(10,150)
# print(S.rect,"pp")

clock = pygame.time.Clock()
done = False
 
while not done:
    print(food.foodlists[0].rect)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            done = True
 
        # Set the direction based on the key pressed
        # We want the speed to be enough that we move a full
        # segment, plus the margin.
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                x_change = (segment_width + segment_margin) * -1
                y_change = 0
            if event.key == pygame.K_RIGHT:
                x_change = (segment_width + segment_margin)
                y_change = 0
            if event.key == pygame.K_UP:
                x_change = 0
                y_change = (segment_height + segment_margin) * -1
            if event.key == pygame.K_DOWN:
                x_change = 0
                y_change = (segment_height + segment_margin)
        # hit_list = pygame.sprite.spritecollide(S, f, True)

 
    # move snake one step
    my_snake.move()
    ![在这里插入图片描述](https://img-blog.csdnimg.cn/20191005235707670.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0NvbGRibG9vZGVkZGQ=,size_16,color_FFFFFF,t_70)
    # -- Draw everything
    # Clear screen
    screen.fill(BLACK)
    my_snake.spriteslist.draw(screen)
    food.foodlist.draw(screen)
    
    # Flip screen
    pygame.display.flip()
 
    # Pause
    clock.tick(5)
 
pygame.quit()

为什么在同一list的元素 rect.x和rect.y 不相同 且有一个不正确