Python贪吃蛇——‘AI’锁头
- 主要任务
- 实现游戏结束判定，包括：
玩家碰到边界、玩家撞到障碍物、玩家撞到AI、AI撞到玩家、玩家撞到自己 - 食物设置、障碍物设置
- 分数设置
- 游戏特点
- AI能实现锁头追踪
具体代码如下：
import pygame
import random
# --- Globals ---
# Colors
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
PINK = (255, 200, 203)
BLUE = (0, 0, 255)
# Screen size
height = 600
width = 600
# 每个蛇身的空隙
segment_margin = 3
# 蛇身的宽高
segment_width = min(height, width) / 40 - segment_margin
segment_height = min(height, width) / 40 - segment_marginclass Obstacle:
"""
障碍物可能会重叠
玩家和AI都不会在一开始就撞上障碍物
以下为自定义地图，而不是随机生成的
"""
def __init__(self):
self.obstacles = []
self.spriteslist = pygame.sprite.Group()
for loc in [4, 20, 35]:
for i in range(random.randrange(1, 4)):
x = (segment_width + segment_margin) * loc - (segment_width + segment_margin) * i
for j in range(random.randrange(1, 4)):
y = (segment_height + segment_margin) * loc - (segment_height + segment_margin) * j
obstacle_item = ObstacleItem(x, y)
self.obstacles.append(obstacle_item)
self.spriteslist.add(obstacle_item)
for loc in [4, 35]:
for i in range(random.randrange(1, 4)):
x = (segment_width + segment_margin) * loc - (segment_width + segment_margin) * i
for j in range(random.randrange(1, 4)):
y = (segment_height + segment_margin) * (40 - loc) - (segment_height + segment_margin) * j
obstacle_item = ObstacleItem(x, y)
self.obstacles.append(obstacle_item)
self.spriteslist.add(obstacle_item)class Food:
def __init__(self):
self.items = []
self.spriteslist = pygame.sprite.Group()
x, y = (segment_width + segment_margin) * 32, (segment_width + segment_margin) * 32
food_item = FoodItem(x, y)
self.items.append(food_item)
self.spriteslist.add(food_item)
def replenish(self):
old_segment = self.items.pop()
self.spriteslist.remove(old_segment)
x = (segment_width + segment_margin) * random.randrange(1, 39)
y = (segment_height + segment_margin) * random.randrange(1, 39)
food_item = FoodItem(x, y)
self.items.append(food_item)
self.spriteslist.add(food_item)class Snake:
# Constructor
def __init__(self,length):
self.segments = []
self.spriteslist = pygame.sprite.Group()
for i in range(length):
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)
# 设定初始速度
self.x_change = segment_width + segment_margin
self.y_change = 0
def move(self):
# 决定身体向哪个方向变化，x_change和y_change通过正负来表示上下左右
x = self.segments[0].rect.x + self.x_change
y = self.segments[0].rect.y + self.y_change
if 0 <= x <= width - segment_width and 0 <= y <= height - segment_height:
# 向蛇头的方向，即前进方向，添加身体，蛇尾减去身体
segment = Segment(x, y)
self.segments.insert(0, segment)
self.spriteslist.add(segment)
# Get rid of last segment of the snake
old_segment = self.segments.pop()
self.spriteslist.remove(old_segment)
def grow(self):
# 因为蛇一直在走，每次走一格
# 所以当它吃到食物时，可以直接加上它的尾巴，因为他的尾巴已经走到尾巴前面一格了
self.segments.append(self.segments[-1])
self.spriteslist.add(self.segments[-1])
def ai_move(self):
x = self.segments[0].rect.x
y = self.segments[0].rect.y
# 当靠近左边界时
if x - (segment_width + segment_margin) <= 0:
# 既靠近左边界又靠近右边界，即‘左上角’
if y - (segment_height + segment_margin) <= 0:
(self.x_change, self.y_change) = (-self.y_change, -self.x_change)
#‘左下角’
elif y + (segment_height + segment_margin) >= height:
(self.x_change, self.y_change) = (self.y_change, self.x_change)
# 靠近右边界
elif x + (segment_width + segment_margin) >= width:
# ‘右上角’
if y - (segment_height + segment_margin) <= 0:
(self.x_change, self.y_change) = (self.y_change, self.x_change)
# ‘右下角’
elif y + (segment_height + segment_margin) >= height:
(self.x_change, self.y_change) = (-self.y_change, -self.x_change)
# 如果只是单纯的要抵达某一边界，交换x、y，这样就实现转弯
if y - (segment_height + segment_margin) <= 0 or y + (segment_height + segment_margin) >= height or \
x + (segment_width + segment_margin) >= width or x - (segment_width + segment_margin) <= 0:
(self.x_change, self.y_change) = (-self.y_change, -self.x_change)
self.move()
# 锁头攻击
def chase(self, snake):
x = snake.segments[0].rect.x
y = snake.segments[0].rect.y
# 玩家蛇 x 坐标离AI很远
if (x - self.segments[0].rect.x) ** 2 >= (y - self.segments[0].rect.y) ** 2: # 比较x、y 的距离差
# 玩家在AI的右边，而AI没有向右走
if x > self.segments[0].rect.x and self.x_change <= 0:
self.x_change = (segment_width + segment_margin)
self.y_change = 0
else:
self.x_change = -(segment_width + segment_margin)
self.y_change = 0
# 玩家蛇 y 坐标离AI很远
else:
# 玩家在AI的下边，而AI没有向下走
if y > self.segments[0].rect.y and self.y_change >= 0:
self.y_change = (segment_height + segment_margin)
self.x_change = 0
else:
self.y_change = -(segment_height + segment_margin)
self.x_change = 0
self.move()class Segment(pygame.sprite.Sprite):
# 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 FoodItem(Segment):
def __init__(self, x, y):
super().__init__(x, y)
self.type = random.randrange(0, 3)
if self.type == 0:
self.points = 1
self.image.fill(GREEN)
elif self.type == 1:
self.points = 2
self.image.fill(PINK)
elif self.type == 2:
self.points = 3
self.image.fill(BLUE)
class ObstacleItem(Segment):
def __init__(self, x, y):
super().__init__(x, y)
self.image.fill(RED)# Call this function so the Pygame library can initialize itself
pygame.init()
# Create a 600x700 sized screen
screen = pygame.display.set_mode([width, height + 100])
# Set the title of the window
pygame.display.set_caption('Snake Game')
# Create an initial snake
my_snake = Snake(3)
food = Food()
obstacle = Obstacle()
ai_snake = Snake(9)
# 初始时 AI远离玩家
for segments in ai_snake.segments:
segments.rect.y = (segment_height + segment_margin) * 35
clock = pygame.time.Clock()
done = False
game_ended = False
"""本地保存每次游戏的分数，找到最高分"""
score = 0
top_score = 0
with open('history.txt', 'r') as f:
scores = f.readlines()
score_list = []
for score_his in scores:
score_his = score_his.strip()
score_list.append(int(score_his))
if score_list:
top_score = max(score_list)count = 0
while not done:
for event in pygame.event.get():
if event.type == pygame.QUIT:
done = True
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_LEFT:
if my_snake.x_change != (segment_width + segment_margin): # 玩家不能直接往回走
my_snake.x_change = (segment_width + segment_margin) * -1
my_snake.y_change = 0
if event.key == pygame.K_RIGHT:
if my_snake.x_change != (segment_width + segment_margin) * -1:
my_snake.x_change = (segment_width + segment_margin)
my_snake.y_change = 0
if event.key == pygame.K_UP:
if my_snake.y_change != (segment_height + segment_margin):
my_snake.x_change = 0
my_snake.y_change = (segment_height + segment_margin) * -1
if event.key == pygame.K_DOWN:
if my_snake.y_change != (segment_height + segment_margin) * -1:
my_snake.x_change = 0
my_snake.y_change = (segment_height + segment_margin)
"""游戏结束的判定：玩家碰到边界、玩家撞到障碍物、玩家撞到AI、AI撞到玩家、玩家撞到自己"""
if my_snake.segments[0].rect.x + segment_width + segment_margin >= width or my_snake.segments[0].rect.x <= 0 or \
my_snake.segments[0].rect.y + segment_height + segment_margin >= height or my_snake.segments[
0].rect.y <= 0 or \
pygame.sprite.spritecollide(my_snake.segments[0], obstacle.spriteslist, False) or \
pygame.sprite.spritecollide(my_snake.segments[0], my_snake.segments[1:], False) or \
pygame.sprite.spritecollide(ai_snake.segments[0], my_snake.spriteslist, False):
# 游戏结束
game_ended = True
screen.fill(BLACK)
font = pygame.font.SysFont('comicsansms', 48)
text = font.render('Top Score : %d' % top_score, True, WHITE)
textrect = text.get_rect(center=(300, 470))
screen.blit(text, textrect)
text = font.render('Game Over.', True, RED)
textrect = text.get_rect(center=(300, 530))
screen.blit(text, textrect)
text_score = font.render('Score : ' + str(score), True, WHITE)
textrect = text_score.get_rect(center=(300, 580))
screen.blit(text_score, textrect)
if not game_ended:
# move snake one step
my_snake.move()
ai_snake.ai_move()
# 循环16次，锁头
if count % 16 == 0:
ai_snake.chase(my_snake)
count +=1
# 游戏界面
screen.fill(BLACK)
# 实时更新当前分数
font = pygame.font.SysFont('comicsansms', 30)
text = font.render('Score = ' + str(score), True, WHITE)
textrect = text.get_rect(center=(100, 600))
screen.blit(text, textrect)
# 显示food的分数
font = pygame.font.SysFont('comicsansms', 20)
text = font.render('■ -- 1', True, GREEN)
textrect = text.get_rect(center=(250, 600))
screen.blit(text, textrect)
text = font.render('■ -- 2', True, PINK)
textrect = text.get_rect(center=(250, 630))
screen.blit(text, textrect)
text = font.render('■ -- 3', True, BLUE)
textrect = text.get_rect(center=(250, 660))
screen.blit(text, textrect)
# 更新屏幕
obstacle.spriteslist.draw(screen)
my_snake.spriteslist.draw(screen)
ai_snake.spriteslist.draw(screen)
food.spriteslist.draw(screen)
if pygame.sprite.spritecollide(my_snake.segments[0], food.spriteslist, False):
my_snake.grow()
score += food.items[0].points
food.replenish()
while pygame.sprite.spritecollide(food.items[0], obstacle.spriteslist, False) or \
pygame.sprite.spritecollide(food.items[0], my_snake.spriteslist, False):
# 确保食物不会一开始，或者随机生成是就落到障碍物和玩家蛇身上
# 如果有，就更新
food.replenish()
# Flip screen
pygame.display.flip()
# Pause
clock.tick(5)
pygame.quit()with open('history.txt', 'a+') as f:
f.write(str(score) + '\n')游戏截图如下：
初始页面
碰到边界
碰到AI
AI碰到玩家
碰到自己
