今天我们用python和python的工具包pygame来编写一个贪吃蛇的小游戏
贪吃蛇游戏功能介绍
贪吃蛇的游戏规则如下：
通过上下左右键或者WASD键来移动蛇来，让它吃到食物，每吃到食物，蛇的长度变长，并获得分数。若蛇碰到游戏边际
或者自身，则蛇死亡，游戏结束。
游戏设计思路
根据游戏规则，我们需要：
1.初始化游戏环境。
2.初始化蛇、食物
3.监听键盘动作
4.蛇的运动，吃食物，是否死亡
5.该局游戏结束，是否还有再玩。
其中的难点在于如何在屏幕上展示蛇的运动，其实我们肉眼所见的蛇的运动并不是真实的，而是在后台通过刷新蛇的坐标而实现的。即可以创建一个蛇的坐标列表，每移动一次，则新的坐标加入，同时删除末尾坐标，看起来像是蛇的在移动。
一个简单地设计框图如下：
代码实现
'''
my_snake.py
@author HelloWorld!
@time:2019.10.27
'''
import random
import pygame
import sys
from pygame.locals import *
windows_width=800 #游戏窗口的大小，原点在左上角
windows_height=600
cell_size=20 #snake 的大小，需被窗口长宽整除
#一些颜色定义
white = (255, 255, 255)
black = (0, 0, 0)
gray = (230, 230, 230)
dark_gray = (40, 40, 40)
DARKGreen = (0, 155, 0)
Green = (0, 255, 0)
Red = (255, 0, 0)
blue = (0, 0, 255)
dark_blue =(0,0, 139)
BG_COLOR = (184,224,217)
#贪吃蛇的地图尺寸
map_width = int(windows_width / cell_size)
map_height = int(windows_height / cell_size)
#蛇的移动速度
snake_speed=5
#方向定义
UP = 1
DOWN = 2
LEFT = 3
RIGHT = 4
#主函数
def main_game():
pygame.init() #初始化gygame
screen=pygame.display.set_mode((windows_width,windows_height))
pygame.display.set_caption("贪吃蛇游戏")
snake_speed_clock = pygame.time.Clock() # 创建Pygame时钟对象
screen.fill(white)
while True:
run_game(screen,snake_speed_clock) #游戏主体
gameover(screen) #游戏结束
def run_game(screen,snake_speed_clock):
#初始化蛇的位置，方向，食物的位置
start_x=random.randint(3,map_width-8)
start_y=random.randint(3,map_width-8)
snake_coords=[{'x':start_x,'y':start_y},{'x':start_x-1,'y':start_y},{'x':start_x-2,'y':start_y}]#初始化snake，也可以用列表的的列表
direction = RIGHT
food=get_random_location()
#循环
while True:
for event in pygame.event.get(): #键盘事件监听
if event.type == pygame.QUIT:
pygame.quit()
sys.exit()
elif event.type == pygame.KEYDOWN: #按键事件
if (event.key==K_LEFT or event.key==K_a) and direction!=RIGHT:
direction=LEFT
elif (event.key==K_RIGHT or event.key==K_d) and direction!=LEFT:
direction=RIGHT
elif (event.key == K_UP or event.key == K_w) and direction != DOWN:
direction = UP
elif (event.key == K_DOWN or event.key == K_s) and direction != UP:
direction = DOWN
elif event.key == K_ESCAPE:
pygame.quit()
sys.exit()
snake_move(direction,snake_coords) #根据方向，移动蛇
alive=snake_is_alive(snake_coords) #判断蛇的死活
if not alive: #如果挂了，则终止循环，跳出run_game函数，执行gameover
break
snake_eat_foods(snake_coords,food) #没挂，则看看迟到食物了吗
screen.fill(BG_COLOR) #游戏背景刷新
#下面draw，是把蛇食物等画出来
draw_snake(screen, snake_coords)
draw_food(screen,food)
draw_score(screen, len(snake_coords) - 3)
# draw_grid(screen)
pygame.display.flip()
#控制执行次数
snake_speed_clock.tick(snake_speed) # 控制fps
#根据移动方向，更新蛇头坐标
def snake_move(directtion,snake_coords):
if directtion==UP:
newHead={'x':snake_coords[0]['x'],'y':snake_coords[0]['y']-1}
elif directtion==DOWN:
newHead = {'x': snake_coords[0]['x'], 'y': snake_coords[0]['y'] + 1}
elif directtion==LEFT:
newHead = {'x': snake_coords[0]['x']-1, 'y': snake_coords[0]['y'] }
elif directtion == RIGHT:
newHead = {'x': snake_coords[0]['x']+1, 'y': snake_coords[0]['y']}
snake_coords.insert(0,newHead)
def snake_is_alive(snake_coords): #碰壁或者碰到自身就是死了
alive=True
if snake_coords[0]['x'] == -1 or snake_coords[0]['x'] == map_width or snake_coords[0]['y'] == -1 or \
snake_coords[0]['y'] == map_height:
alive=False
for snake_body in snake_coords[1:]:
if snake_coords[0]['x']==snake_body['x'] and snake_coords[0]['y']==snake_body['y']:
alive=False
return alive
#坐标重合，表示吃到食物了，否则就没有，则移动，把
def snake_eat_foods(snake_coords,food):
if snake_coords[0]['x']==food['x'] and snake_coords[0]['y']==food['y']:
food['x']=random.randint(0, map_width-1)
food['y']=random.randint(0, map_height-1)
else:
del snake_coords[-1]
def get_random_location(): #食物的坐标随机生成
return {'x':random.randint(0,map_width-1),'y':random.randint(0,map_height-1)}
def draw_snake(screen, snake_coords):
for coord in snake_coords:
x=coord['x']*cell_size
y=coord['y']*cell_size
segmentRect=pygame.Rect(x,y,cell_size,cell_size)
pygame.draw.rect(screen,dark_blue,segmentRect)
def draw_food(screen,food):
x=food['x']*cell_size
y=food['y']*cell_size
foodRect=pygame.Rect(x,y,cell_size,cell_size)
pygame.draw.rect(screen,Red,foodRect)
def draw_grid(screen):
for x in range(0,windows_width,cell_size):
pygame.draw.line(screen,gray,(x,0),(x,windows_height))
for y in range(0,windows_height,cell_size):
pygame.draw.line(screen,gray,(0,y),(windows_width,y))
def draw_score(screen, score):
font = pygame.font.SysFont(None, 40)
score_str = "{:,}".format(score)
score_image=font.render('Score: '+score_str,True,Green,gray)
score_rect=score_image.get_rect()
score_rect.topleft=(windows_width-200,10)
screen.blit(score_image, score_rect)
def gameover(screen):
font=pygame.font.SysFont(None, 40)
tips=font.render('Press Q or ESC to quit; Press anykey to continue',True, (65, 105, 225))
screen.blit(tips,(80, 300))
pygame.display.update()
while True:
for event in pygame.event.get():
if event.type==QUIT:
pygame.quit()
sys.exit()
elif event.type == KEYDOWN:
if event.key == K_ESCAPE or event.key == K_q: # 终止程序
pygame.quit()
sys.exit() # 终止程序
else:
return # 结束此函数, 重新开始游戏
if __name__=='__main__':
main_game() 
