之前用pygame做了一个小游戏给小宝贝练习加法。现在进入减法的学习阶段，减法需要逆向思维，对小孩来说比加法更难理解一些。也需要更多的练习来熟悉，就在原来程序的基础上修改了一下。现在可以练习减法。
一、编程目标
- 1、将原来的加法练习修改为减法。
- 2、增加奖惩机制，左上方有三个头像，打错一题会掉一个头像，三个头像掉完，游戏结束。右上方显示得分，答对一题奖励一分。
二、编程思路
1、生成题目
先随机生成3个10以内的整数作为备选答案，然后从这三个数中随机挑选一个作为答案也就是两个数的差。再随机生成一个整数作为减数，差和减数相加得到被减数，在出题的地方列出算式。为了限制难度，用while循环检查被减数，如果大于10就重新生成一遍被减数、减数和差。不过实际运行的时候发现，这有时会引起一个问题，就是，选项可能会出现两个相同的答案。正在想办法解决。
代码：
def update_question(pre_idx=0):
answers=random.sample(range(1,11),3)
brick1.answer_number=answers[0]
brick2.answer_number=answers[1]
brick3.answer_number=answers[2]
brick_list=[brick1,brick2,brick3]
idx=random.sample(range(0,3),1)[0]
while idx == pre_idx:
idx=random.sample(range(0,3),1)[0]
sub_num[1]=random.randint(0,answers[idx])
sub_num[0]=answers[idx]+sub_num[1]
while sub_num[0] > 10:
answers[idx]=random.sample(range(1,11),1)[0]
brick_list[idx].answer_number=answers[idx]
sub_num[0]=answers[idx]+sub_num[1]
QuestionBanner.image.fill((0,0,255))
QuestionBanner.text = str(sub_num[0])+'-'+str(sub_num[1])+'=?'
2、生命计数
建立一个生命计数的类（life_count)，类的功能就是载入头像图片，然后创立三个实例，加入all_sprites组里面。如果答错，就将一个实例移出all_sprites组。这样对应的头像就会从屏幕上消失。
设置了一个变量叫“可以掉命”（can_lose_life），如果这个参数为真并且跳上了错误的数字平台，就会有一个头像消失。如果不用这个参数，由于程序主体没秒钟执行30次。在下落过程中，三个头像就全部掉完了。所以掉一个头像之后，要把这个变量设置为假，这样一次就只掉一个头像。另外经过多次试验，当人物落到答案数字平台下方之后，应该把can_lose_life变量再次设置为真。
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全部源代码：
# -*- coding: utf-8 -*-
import pygame
import random
gravity = 1.2
support = 0
pygame.init()
screen = pygame.display.set_mode((400,800))#,pygame.FULLSCREEN|pygame.SCALED)
background = pygame.image.load('image\Background.jpg')
background = pygame.transform.smoothscale(background,(400,800))
class Player(pygame.sprite.Sprite):
def __init__(self):
pygame.sprite.Sprite.__init__(self)
self.image = pygame.image.load('image\player.jpg').convert()
pygame.Surface.set_colorkey(self.image,(0,0,0))
self.image = pygame.transform.smoothscale(self.image,(80,90))
self.rect=self.image.get_rect()
self.rect.center =(200,700)
self.vel_x = 0
self.vel_y = 0
self.jumping = False
self.last_update = 0
def update(self):
global gravity
global support
self.vel_y += gravity+support
self.rect=self.rect.move(self.vel_x,self.vel_y)
if self.rect.right < 0:
self.rect.left = 400
if self.rect.left > 400:
self.rect.right = 0
if self.rect.bottom >= 725:
self.rect.bottom =725
support = -1*gravity
self.jumping = False
else:
support = 0
if support == 0:
self.jumping = True
class life(pygame.sprite.Sprite):
def __init__(self,path2img,center_x,center_y):
pygame.sprite.Sprite.__init__(self)
self.image = pygame.image.load(path2img).convert()
pygame.Surface.set_colorkey(self.image,(0,0,0))
self.image = pygame.transform.smoothscale(self.image,(80,80))
self.rect=self.image.get_rect()
self.score=0
self.rect.center=(center_x,center_y)
def update(self):
pass
class brick(pygame.sprite.Sprite):
def __init__(self,center_x,center_y,answer_number,idx):
pygame.sprite.Sprite.__init__(self)
self.image = pygame.Surface((50,50))
self.image.fill((255,0,0))
self.rect=self.image.get_rect()
self.rect.center =(center_x,center_y)
self.font = pygame.font.Font('segoeprb.ttf',32)
self.answer_number = answer_number
self.idx = idx
def update(self):
self.image.fill((255,0,0))
choice_number = self.font.render(str(self.answer_number),True,(0,255,0))
self.image.blit(choice_number,(5,-10))
class question_banner(pygame.sprite.Sprite):
def __init__(self,center_x,center_y,question):
pygame.sprite.Sprite.__init__(self)
self.text = question
self.font = pygame.font.Font('segoeprb.ttf',64)
self.image = pygame.Surface((300,80))
self.image.fill((0,0,255))
self.rect=self.image.get_rect()
self.rect.center =(center_x,center_y)
def update(self):
question_img = self.font.render(self.text,True,(255,0,0))
self.image.blit(question_img,(10,-10))
class Score(pygame.sprite.Sprite):
def __init__(self,center_x,center_y,score):
pygame.sprite.Sprite.__init__(self)
self.text = score
self.font = pygame.font.Font('segoeprb.ttf',64)
self.image = pygame.Surface((80,80))
self.image.fill((0,0,255))
self.rect=self.image.get_rect()
self.rect.center =(center_x,center_y)
def update(self):
score_img = self.font.render(self.text,True,(255,0,0))
self.image.blit(score_img,)
def update(self):
question_img = self.font.render(self.text,True,(255,0,0))
self.image.blit(question_img,(10,-10))
class contral(pygame.sprite.Sprite):
def __init__(self,image,x,y):
pygame.sprite.Sprite.__init__(self)
self.image=pygame.image.load(image)
self.image = pygame.transform.smoothscale(self.image,(60,40))
self.rect = self.image.get_rect()
self.rect.center = (x,y)
def update(self):
pass
sub_num=[2,1]
all_sprites= pygame.sprite.Group()
player = Player()
life1= life('image\Avatar.png',50,200)
life2= life('image\Avatar.png',110,200)
life3= life('image\Avatar.png',170,200)
life_count=[life1,life2,life3]
brick1 = brick(80,600,1,0)
brick2 = brick(200,600,2,1)
brick3 = brick(320,600,3,2)
QuestionBanner = question_banner(200,100,str(sub_num[0])+'-'+str(sub_num[1])+'=?')
can_lose_life = True
score = 0
score_board = Score(300,200,str(score))
right_arrow = contral('image\Right.png',350,750)
left_arrow = contral('image\Left.png',50,750)
all_sprites.add(player,brick1,brick2,brick3,QuestionBanner,right_arrow,left_arrow,life1,life2,life3,score_board)
bricks = pygame.sprite.Group()
bricks.add(brick1,brick2,brick3)
clock = pygame.time.Clock()
def update_question(pre_idx=0):
answers=random.sample(range(1,11),3)
brick1.answer_number=answers[0]
brick2.answer_number=answers[1]
brick3.answer_number=answers[2]
brick_list=[brick1,brick2,brick3]
idx=random.sample(range(0,3),1)[0]
while idx == pre_idx:
idx=random.sample(range(0,3),1)[0]
sub_num[1]=random.randint(0,answers[idx])
sub_num[0]=answers[idx]+sub_num[1]
while sub_num[0] > 10:
answers[idx]=random.sample(range(1,11),1)[0]
brick_list[idx].answer_number=answers[idx]
sub_num[0]=answers[idx]+sub_num[1]
QuestionBanner.image.fill((0,0,255))
QuestionBanner.text = str(sub_num[0])+'-'+str(sub_num[1])+'=?'
running = True
while running:
clock.tick(30)
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
if event.type == pygame.MOUSEBUTTONDOWN and event.button ==1:
if left_arrow.rect.collidepoint(event.pos):
player.vel_x -= 5
elif right_arrow.rect.collidepoint(event.pos):
player.vel_x = 5
if player.rect.collidepoint(event.pos):
player.vel_y = -20
elif event.type == pygame.MOUSEBUTTONUP:
player.vel_x = 0
#update
all_sprites.update()
hits = pygame.sprite.spritecollide(player,bricks,False)
if not hits:
ready2change_question = True
if hits and player.vel_y > 0:
player.last_update = pygame.time.get_ticks()
if not hits and player.vel_y>0 and player.rect.top>625:
can_lose_life = True
if hits and player.vel_y >= 0:
if sub_num[0]-sub_num[1]==hits[0].answer_number:
player.vel_y = 0
player.rect.bottom = hits[0].rect.top+1
support = -1*gravity
player.jumping = False
now = pygame.time.get_ticks()
if ready2change_question and now - player.last_update>1500:
update_question(hits[0].idx)
ready2change_question = False
score += 1
score_board.image.fill((0,0,255))
score_board.text = str(score)
print(score)
can_lose_life = False
elif can_lose_life:
all_sprites.remove(life_count[-1])
life_count.pop()
can_lose_life = False
#render
screen.blit(background,(0,0))
all_sprites.draw(screen)
pygame.display.update()