请参考前面的教程篇 《玩蛇系列之Pygame教程（十一）-- Wormy贪吃蛇》
以前在网上看到过一个动图，很好玩，就是贪吃蛇自己吃苹果，然后把全屏都占满了，感觉确实很酷，我就想能不能把我们的这个版本也改成贪吃蛇自动寻找食物。
- 由于时间关系还是有bug，贪吃蛇容易把自己把自己圈起来，就出不去了。
实现也是比较简单，在游戏主循环里每次都生成一个最佳的best_move，来替代原来程序中的用户的输入，
但是关键就是这个best_move的生成，还是很有得研究的，我采用的就比较简单粗暴的办法：
搜索所有的方格，计算该方格到苹果方格的距离（权值）
res=abs(i-a_x)+abs(j-a_y)
然后获得蛇头上下左右四个方格的权值，选出其中最小的作为best_move。
有bug哦，各位大神可以尽情修改哦，改好了记得告诉我一声，膜拜一下！
GitHub：https://github.com/ckdroid/PygameLearning
下面是代码：
# -*- coding: UTF-8 -*-
'''
Created on 2017年1月7日
@author: 小峰峰
'''
import random, sys, time, pygame
from pygame.locals import *
FPS = 10 # 屏幕刷新率（在这里相当于贪吃蛇的速度）
WINDOWWIDTH = 400 # 屏幕宽度
WINDOWHEIGHT = 300 # 屏幕高度
CELLSIZE = 20 # 小方格的大小
# 断言，屏幕的宽和高必须能被方块大小整除
assert WINDOWWIDTH % CELLSIZE == 0, "Window width must be a multiple of cell size."
assert WINDOWHEIGHT % CELLSIZE == 0, "Window height must be a multiple of cell size."
# 横向和纵向的方格数
CELLWIDTH = int(WINDOWWIDTH / CELLSIZE)
CELLHEIGHT = int(WINDOWHEIGHT / CELLSIZE)
FIELD_SIZE = CELLHEIGHT * CELLWIDTH
# 定义几个常用的颜色
# R G B
WHITE = (255, 255, 255)
BLACK = ( 0, 0, 0)
RED = (255, 0, 0)
GREEN = ( 0, 255, 0)
DARKGREEN = ( 0, 155, 0)
DARKGRAY = ( 40, 40, 40)
BGCOLOR = BLACK
# 定义贪吃蛇的动作
UP = 'up'
DOWN = 'down'
LEFT = 'left'
RIGHT = 'right'
# 错误码
ERR = -1111
# 贪吃蛇的头（）
HEAD = 0 # syntactic sugar: index of the worm's head
# 运动方向数组
mov = [LEFT, RIGHT, UP, DOWN]
board = [[0 for x in range(CELLWIDTH)] for y in range(CELLHEIGHT+1)]
def find_best_move(apple,wormCoords,board,direction):
best_move = ERR
# 蛇头
w_x=wormCoords[HEAD]['x']
w_y=wormCoords[HEAD]['y']
# 苹果
a_x=apple['x']
a_y=apple['y']
for i in xrange (CELLWIDTH):
for j in xrange (CELLHEIGHT):
cell = {'x':i,'y':j}
cell_free = is_cell_free(cell, wormCoords)
if(cell_free):
# 计算
res=abs(i-a_x)+abs(j-a_y)
board[j][i]=res
else:
board[j][i]='x'
for i in xrange (CELLHEIGHT):
print board[i]
# 边界处理
if(w_y-1<0):
u=100
else:
u=board[w_y-1][w_x]
if(w_y+1>CELLHEIGHT-1):
d=100
else:
d=board[w_y+1][w_x]
if(w_x-1<0):
l=100
else:
l=board[w_y][w_x-1]
if(w_x+1>CELLWIDTH-1):
r=100
else:
r=board[w_y][w_x+1]
# 选择最小的作为best_move
m=min(u,d,l,r)
if(m==u):
best_move=UP
if(m==d):
best_move=DOWN
if(m==l):
best_move=LEFT
if(m==r):
best_move=RIGHT
print u,d,l,r
print best_move
return best_move
def main():
# 定义全局变量
global FPSCLOCK, DISPLAYSURF, BASICFONT
pygame.init() # 初始化pygame
FPSCLOCK = pygame.time.Clock() # 获得pygame时钟
DISPLAYSURF = pygame.display.set_mode((WINDOWWIDTH, WINDOWHEIGHT)) # 设置屏幕宽高
BASICFONT = pygame.font.Font('resource/PAPYRUS.ttf', 18) # BASICFONT
pygame.display.set_caption('Wormy') # 设置窗口的标题
showStartScreen() # 显示开始画面
while True:
# 这里一直循环于开始游戏和显示游戏结束画面之间，
# 运行游戏里有一个循环，显示游戏结束画面也有一个循环
# 两个循环都有相应的return，这样就可以达到切换这两个模块的效果
runGame() # 运行游戏
showGameOverScreen() # 显示游戏结束画面
def runGame():
# 随机初始化设置一个点作为贪吃蛇的起点
startx = random.randint(5, CELLWIDTH - 6)
starty = random.randint(5, CELLHEIGHT - 6)
# 以这个点为起点，建立一个长度为3格的贪吃蛇（数组）
wormCoords = [{'x': startx, 'y': starty},
{'x': startx - 1, 'y': starty},
{'x': startx - 2, 'y': starty}]
direction = RIGHT # 初始化一个运动的方向
# 随机一个apple的位置
apple = getRandomLocation(wormCoords)
while True: # 游戏主循环
for event in pygame.event.get(): # 事件处理
if event.type == QUIT: # 退出事件
terminate()
elif event.type == KEYDOWN: # 按键事件
#如果按下的是左键或a键，且当前的方向不是向右，就改变方向，以此类推
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:
terminate()
# best_move=random.choice(mov)
best_move=find_best_move(apple,wormCoords,board,direction)
print best_move
direction=best_move
# 检查贪吃蛇是否撞到撞到边界
if wormCoords[HEAD]['x'] == -1 or wormCoords[HEAD]['x'] == CELLWIDTH or wormCoords[HEAD]['y'] == -1 or wormCoords[HEAD]['y'] == CELLHEIGHT:
return # game over
# 检查贪吃蛇是否撞到自己
for wormBody in wormCoords[1:]:
if wormBody['x'] == wormCoords[HEAD]['x'] and wormBody['y'] == wormCoords[HEAD]['y']:
return # game over
# 检查贪吃蛇是否吃到apple
if wormCoords[HEAD]['x'] == apple['x'] and wormCoords[HEAD]['y'] == apple['y']:
# 不移除蛇的最后一个尾巴格
apple = getRandomLocation(wormCoords) # 重新随机生成一个apple
else:
del wormCoords[-1] # 移除蛇的最后一个尾巴格
# 根据方向，添加一个新的蛇头，以这种方式来移动贪吃蛇
if direction == UP:
newHead = {'x': wormCoords[HEAD]['x'], 'y': wormCoords[HEAD]['y'] - 1}
elif direction == DOWN:
newHead = {'x': wormCoords[HEAD]['x'], 'y': wormCoords[HEAD]['y'] + 1}
elif direction == LEFT:
newHead = {'x': wormCoords[HEAD]['x'] - 1, 'y': wormCoords[HEAD]['y']}
elif direction == RIGHT:
newHead = {'x': wormCoords[HEAD]['x'] + 1, 'y': wormCoords[HEAD]['y']}
# 插入新的蛇头在数组的最前面
wormCoords.insert(0, newHead)
# 绘制背景
DISPLAYSURF.fill(BGCOLOR)
# 绘制所有的方格
drawGrid()
# 绘制贪吃蛇
drawWorm(wormCoords)
# 绘制apple
drawApple(apple)
# 绘制分数（分数为贪吃蛇数组当前的长度-3）
drawScore(len(wormCoords) - 3)
# 更新屏幕
pygame.display.update()
# 设置帧率
FPSCLOCK.tick(FPS)
# 绘制提示消息
def drawPressKeyMsg():
pressKeySurf = BASICFONT.render('Press a key to play.', True, DARKGRAY)
pressKeyRect = pressKeySurf.get_rect()
pressKeyRect.topleft = (WINDOWWIDTH - 200, WINDOWHEIGHT - 30)
DISPLAYSURF.blit(pressKeySurf, pressKeyRect)
# 检查按键是否有按键事件
def checkForKeyPress():
if len(pygame.event.get(QUIT)) > 0:
terminate()
keyUpEvents = pygame.event.get(KEYUP)
if len(keyUpEvents) == 0:
return None
if keyUpEvents[0].key == K_ESCAPE:
terminate()
return keyUpEvents[0].key
# 显示开始画面
def showStartScreen():
DISPLAYSURF.fill(BGCOLOR)
titleFont = pygame.font.Font('resource/PAPYRUS.ttf', 100)
titleSurf = titleFont.render('Wormy!', True, GREEN)
titleRect = titleSurf.get_rect()
titleRect.center = (WINDOWWIDTH / 2, WINDOWHEIGHT / 2)
DISPLAYSURF.blit(titleSurf, titleRect)
drawPressKeyMsg()
pygame.display.update()
while True:
if checkForKeyPress():
pygame.event.get() # clear event queue
return
# 退出
def terminate():
pygame.quit()
sys.exit()
# 检查一个cell有没有被蛇身覆盖，没有覆盖则为free，返回true
def is_cell_free(idx, psnake):
return not (idx in psnake)
# 随机生成一个坐标位置
def getRandomLocation(wormCoords):
cell_free = False
while not cell_free:
w = random.randint(0, CELLWIDTH - 1)
h = random.randint(0, CELLHEIGHT - 1)
food = {'x':w,'y':h}
cell_free = is_cell_free(food, wormCoords)
# return {'x': random.randint(0, CELLWIDTH - 1), 'y': random.randint(0, CELLHEIGHT - 1)}
return food
# 显示游戏结束画面
def showGameOverScreen():
gameOverFont = pygame.font.Font('resource/PAPYRUS.ttf', 50)
gameSurf = gameOverFont.render('Game', True, WHITE)
overSurf = gameOverFont.render('Over', True, WHITE)
gameRect = gameSurf.get_rect()
overRect = overSurf.get_rect()
gameRect.midtop = (WINDOWWIDTH / 2, WINDOWHEIGHT / 2-gameRect.height-10)
overRect.midtop = (WINDOWWIDTH / 2, WINDOWHEIGHT / 2)
DISPLAYSURF.blit(gameSurf, gameRect)
DISPLAYSURF.blit(overSurf, overRect)
drawPressKeyMsg()
pygame.display.update()
pygame.time.wait(500)
checkForKeyPress() # clear out any key presses in the event queue
while True:
if checkForKeyPress():
pygame.event.get() # clear event queue
return
# 绘制分数
def drawScore(score):
scoreSurf = BASICFONT.render('Score: %s' % (score), True, WHITE)
scoreRect = scoreSurf.get_rect()
scoreRect.topleft = (WINDOWWIDTH - 120, 10)
DISPLAYSURF.blit(scoreSurf, scoreRect)
# 根据 wormCoords 数组绘制贪吃蛇
def drawWorm(wormCoords):
for coord in wormCoords:
x = coord['x'] * CELLSIZE
y = coord['y'] * CELLSIZE
wormSegmentRect = pygame.Rect(x, y, CELLSIZE, CELLSIZE)
pygame.draw.rect(DISPLAYSURF, DARKGREEN, wormSegmentRect)
wormInnerSegmentRect = pygame.Rect(x + 4, y + 4, CELLSIZE - 8, CELLSIZE - 8)
pygame.draw.rect(DISPLAYSURF, GREEN, wormInnerSegmentRect)
# 根据 coord 绘制 apple
def drawApple(coord):
x = coord['x'] * CELLSIZE
y = coord['y'] * CELLSIZE
appleRect = pygame.Rect(x, y, CELLSIZE, CELLSIZE)
pygame.draw.rect(DISPLAYSURF, RED, appleRect)
# 绘制所有的方格
def drawGrid():
for x in range(0, WINDOWWIDTH, CELLSIZE): # draw vertical lines
pygame.draw.line(DISPLAYSURF, DARKGRAY, (x, 0), (x, WINDOWHEIGHT))
for y in range(0, WINDOWHEIGHT, CELLSIZE): # draw horizontal lines
pygame.draw.line(DISPLAYSURF, DARKGRAY, (0, y), (WINDOWWIDTH, y))
if __name__ == '__main__':
main()
