用python写一个贪吃蛇

好的，下面是一个简单的贪吃蛇游戏，使用 Python 和 Pygame 库编写：

import pygame
import random

# 初始化 Pygame 库
pygame.init()

# 游戏窗口尺寸和标题
SCREEN_WIDTH = 600
SCREEN_HEIGHT = 600
SCREEN_TITLE = '贪吃蛇游戏'

# 定义颜色
BLACK_COLOR = (0, 0, 0)
WHITE_COLOR = (255, 255, 255)
RED_COLOR = (255, 0, 0)
GREEN_COLOR = (0, 255, 0)
BLUE_COLOR = (0, 0, 255)

# 创建游戏窗口
SCREEN = pygame.display.set_mode((SCREEN_WIDTH, SCREEN_HEIGHT))
pygame.display.set_caption(SCREEN_TITLE)

# 定义贪吃蛇类
class Snake:
    def __init__(self):
        self.length = 1
        self.positions = [(SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2)]
        self.direction = random.choice([UP, DOWN, LEFT, RIGHT])
        self.color = GREEN_COLOR
        self.score = 0

    def get_head_position(self):
        return self.positions[0]

    def turn(self, point):
        if self.length > 1 and (point[0]*-1,point[1]*-1) == self.direction:
            return
        else:
            self.direction = point

    def move(self):
        cur = self.get_head_position()
        x, y = self.direction
        new = ((cur[0] + (x*GRID_SIZE)), (cur[1] + (y*GRID_SIZE)))
        if new in self.positions[2:]:
            self.reset()
        else:
            self.positions.insert(0, new)
            if len(self.positions) > self.length:
                self.positions.pop()

    def reset(self):
        self.length = 1
        self.positions = [(SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2)]
        self.direction = random.choice([UP, DOWN, LEFT, RIGHT])
        self.score = 0

    def draw(self, surface):
        for p in self.positions:
            r = pygame.Rect((p[0], p[1]), (GRID_SIZE, GRID_SIZE))
            pygame.draw.rect(surface, self.color, r)
            pygame.draw.rect(surface, BLACK_COLOR, r, 1)

    def handle_keys(self):
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                exit()
            elif event.type == pygame.KEYDOWN:
                if event.key == pygame.K_UP:
                    self.turn(UP)
                elif event.key == pygame.K_DOWN:
                    self.turn(DOWN)
                elif event.key == pygame.K_LEFT:
                    self.turn(LEFT)
                elif event.key == pygame.K_RIGHT:
                    self.turn(RIGHT)

# 定义食物类
class Food:
    def __init__(self):
        self.position = (0, 0)
        self.color = RED_COLOR
        self.randomize_position()

    def randomize_position(self):
        self.position = (random.randint(0, GRID_WIDTH-1) * GRID_SIZE, random.randint(0, GRID_HEIGHT-1) * GRID_SIZE)

    def draw(self, surface):
        r = pygame.Rect((self.position[0], self.position[1]), (GRID_SIZE, GRID_SIZE))
        pygame.draw.rect(surface, self.color, r)
        pygame.draw.rect(surface, BLACK_COLOR, r, 1)

# 定义游戏主函数
def main():
    pygame.mixer.init()
    pygame.mixer.music.load('bg_music.mp3')
    pygame.mixer.music.play(-1, 0.0)
    snake = Snake()
    food = Food()
    score_font = pygame.font.SysFont('arial', 26)

    while True:
        # 处理按键事件
        snake.handle_keys()
        # 移动贪吃蛇
        snake.move()
        # 判断是否吃到食物
        if snake.get_head_position() == food.position:
            snake.length += 1
            snake.score += 1
            food.randomize_position()
        # 绘制游戏界面
        SCREEN.fill(WHITE_COLOR)
        snake.draw(SCREEN)
        food.draw(SCREEN)
        score_text = 'Score: ' + str(snake.score)
        score_surface = score_font.render(score_text, True, BLACK_COLOR)
        SCREEN.blit(score_surface, (SCREEN_WIDTH - score_surface.get_width() - 10, 10))
        pygame.display.update()
        # 判断是否撞墙
        if snake.get_head_position()[0] < 0 or snake.get_head_position()[0] > SCREEN_WIDTH-GRID_SIZE:
            snake.reset()
        elif snake.get_head_position()[1] < 0 or snake.get_head_position()[1] > SCREEN_HEIGHT-GRID_SIZE:
            snake.reset()

# 定义方向常量
UP = (0, -1)
DOWN = (0, 1)
LEFT = (-1, 0)
RIGHT = (1, 0)

# 定义格子大小和数量
GRID_SIZE = 20
GRID_WIDTH = SCREEN_WIDTH / GRID_SIZE
GRID_HEIGHT = SCREEN_HEIGHT / GRID_SIZE

if __name__ == '__main__':
    main()

运行代码后，会弹出一个游戏窗口，按上、下、左、右键控制贪吃蛇移动，吃到食物后贪吃蛇会变长，撞墙或自己会死亡，每吃到一个食物得分加一。