Python编程从入门到实践练习13-3、13-4

13-3 雨滴：寻找一幅雨滴图像，并创建一系列整齐排列的雨滴。让这些雨滴往下落，直到到达屏幕后消失。

先说今天的问题：

1.在更改函数形参时，调用的时候也要修改，否则会出现AttributeError

    值得注意的是：每当添加进新的代码，要检查函数传递的参数是否对应一致，函数本身与调用它的时候都要检查

2.愚蠢的错误：把创建整齐雨滴的函数写到循环体中去了，结果一直出现重叠，达不到预期效果，搞了半天眼睛快瞎了才发现，    唉！

主程序 display

import pygame


from settings import Settings

from rain import Rain

import func as f

from pygame.sprite import Group#####

def display():
	"""主函数----显示雨滴效果"""
	pygame.init()
	settings = Settings()
	screen = pygame.display.set_mode((settings.screen_width, settings.screen_height))
	pygame.display.set_caption('Raining')
	rains = Group()####
	f.create_rains(settings, screen, rains)#####
	while True:
		f.check_events()
		screen.fill(settings.bg_color)
		f.change_direction(settings, rains)
		rains.draw(screen)
		pygame.display.flip()

display()

函数模块func

import pygame

import sys

from rain import Rain


def check_events():
	"""按键检查"""
	for event in pygame.event.get():
			if event.type == pygame.QUIT:
				sys.exit()

def get_col_numbers(settings, rain):#对于每一行来说，变化的是x坐标，列在变化
	"""一行可以存放的雨滴数"""
	col_numbers = int(settings.screen_width / (2 * rain.rect.width))
	return col_numbers

def get_row_numbers(settings, rain):
	"""可存放雨滴的行数"""
	row_numbers = int(settings.screen_height / (1 * rain.rect.height))
	return row_numbers

def create_rain(settings, screen, rains, col_number, row_number):
	rain = Rain(settings, screen)
	rain_width = rain.rect.width
	rain.x = rain_width + 2 * rain_width * col_number
	rain.rect.x = rain.x#rect存放整数
	rain.rect.y = rain.rect.y + 2 * rain.rect.height * row_number
	rains.add(rain)

def create_rains(settings, screen, rains):
	rain = Rain(settings, screen)#这句是要写的，不写的话get_col_numbers()中的rain将出现NameError
	col_numbers = get_col_numbers(settings, rain)
	row_numbers = get_row_numbers(settings, rain)
	for row_number in range(row_numbers):
		for col_number in range(col_numbers):
			create_rain(settings, screen, rains, col_number, row_number)

def change_direction(settings, rains):
	for rain in rains.sprites():
		rain.rect.y += settings.drop_speed

		

		

rain类：

import pygame

from pygame.sprite import Sprite

class Rain(Sprite):
	"""雨滴"""
	def __init__(self, settings, screen):
		super().__init__()
		self.screen = screen
		self.settings = settings
		self.image = pygame.image.load('rain.bmp')
		self.rect = self.image.get_rect()
		
		self.y = float(self.rect.y)
		
	def blitme(self):
		self.screen.blit(self.image, self.rect)
	

settings类：

class Settings():
	"""设置所有设置的类"""
	def __init__(self):
		self.screen_width = 1200
		self.screen_height = 600
		self.bg_color = (255, 255, 255)
		self.drop_speed = 1

效果图：

初始：

下落：

13-4 连绵细雨：使得一行雨滴消失在屏幕低端后，屏幕顶端又出现一行新的雨滴，并开始往下落

新增函数：

def update_rains(settings, screen, rains):
	for rain in rains.sprites():
		if rain.check_edges():
			new_rain = Rain(settings, screen)
			new_rain.rect.x = rain.rect.x
			rains.remove(rain)
			rains.add(new_rain)
		print(len(rains))	

主程序改动：

while True:
		f.check_events()
		screen.fill(settings.bg_color)
		f.change_direction(settings, rains)
		f.update_rains(settings, screen, rains)
		rains.draw(screen)
		pygame.display.flip()

效果：

初始：

运行中：

rains编组的长度（始终不变）：

未解决的疑惑：

1.程序刚开始运行时较慢，下落速度较慢，几秒后变正常

2.rains编组中数值为什么是35？屏幕大小存放的三行rain，应该是21，运行时为什么变成35？