Python编程：从入门到实践，课后题13-5

自学Python两三个月了，深感智商的欠缺，思维方式比较线性，毕竟是一个大学只学过一门VB的女同学 。所以学编程的道路上经常遇到障碍，笨笨……一个小问题都会牵出很深奥的知识。发现这本书的第二部分网上找不到参考答案，就分享一个自己研究了很多天（真的是好几天，?），最后做的还算成功的13.5。编程真的很奇妙，虽然我学的很笨拙，但是成就感还是要爆了……

import pygame
import sys
from random import randint
from pygame.sprite import Sprite
from pygame.sprite import Group

pygame.init()
bg_color=(20,40,50)
screen=pygame.display.set_mode((1200,700))
random_number=randint(1,1200)
dropspeed=3
speed_factor=5

class Doll(Sprite):
	"""docstring for Doll"""
	def __init__(self, screen):
		super(Doll, self).__init__()
		self.screen = screen
		self.image=pygame.image.load('timg.bmp')
		self.rect=self.image.get_rect()
		self.screen_rect=self.screen.get_rect()
		self.rect.centerx=self.screen_rect.centerx
		self.rect.bottom=self.screen_rect.bottom
		self.moving_right=False
		self.moving_left=False
	def blitme(self):
		self.screen.blit(self.image,self.rect)	
	def update(self):
		if self.moving_right and self.rect.right<self.screen_rect.right:
			self.rect.centerx+=speed_factor
		if self.moving_left and self.rect.left>0:
			self.rect.centerx-=speed_factor

class Water(Sprite):
	def __init__(self,screen,random_number):
		super(Water, self).__init__()
		self.screen=screen
		self.image=pygame.image.load("raindrop.bmp")
		self.rect=self.image.get_rect()
		self.screen_rect=self.screen.get_rect()
		self.rect.centerx=random_number
		self.rect.top=0
		self.y=float(self.rect.y)
	def blitme(self):
		self.screen.blit(self.image,self.rect)
	def update(self):
		self.y+=dropspeed
		self.rect.y=self.y

	def fail(self):		
		if self.rect.top>=self.screen_rect.bottom:
			print("no")
			waters.empty()
			random_number=randint(1,1200)
			water=Water(screen,random_number)
			waters.add(water)

def catch_water(doll,water,waters):     	
	catch=pygame.sprite.spritecollide(doll,waters,True,collided=None)
	#曾经前边有doll=Doll（）……导致在只有移动娃娃才能接到水珠的情况下，水珠不消失
	for water in waters:#之前丢了这句，就不是遍历了！！！！
		if water.rect.top>=water.screen_rect.bottom:
			waters.empty()
			
	if len(waters)==0:
		random_number=randint(1,1200)
		water=Water(screen,random_number)
		waters.add(water)			

def check_keydown_events(event,doll):
	if event.key==pygame.K_RIGHT:
		doll.moving_right=True
	elif event.key==pygame.K_LEFT:
		doll.moving_left=True

def check_keyup_events(event,doll):
	if event.key==pygame.K_RIGHT:
		doll.moving_right=False
	elif event.key==pygame.K_LEFT:
		doll.moving_left=False
	
def event_check(doll):
	for event in pygame.event.get():
		if event.type==pygame.QUIT:
			sys.exit()
		elif event.type==pygame.KEYDOWN:
			check_keydown_events(event,doll)
		elif event.type==pygame.KEYUP:
			check_keyup_events(event,doll)

def rungame():
	water=Water(screen,random_number)
	waters=Group()	
	waters.add(water)
	doll=Doll(screen)
	while True:
		screen.fill(bg_color) #这一步很重要啊，要是挪到True以前，娃娃就会出现重影，擦掉背景色。
		doll.blitme()
		waters.draw(screen)
		pygame.display.flip()	
		event_check(doll)
		doll.update()
		waters.update()		
		catch_water(doll,water,waters)
	
rungame()