13_1-13_2
13_1 星星主程序：
import sys
import pygame
from settings import Settings
from ship import Ship
from bullet import Bullet
from alien import Alien
class AlienInvasion:
"""Overall class to manage game assets and behavior."""
def __init__(self):
"""Initialize the game, and create game resources."""
pygame.init()
self.settings = Settings()
self.screen = pygame.display.set_mode((0, 0), pygame.FULLSCREEN)
self.settings.screen_width = self.screen.get_rect().width
self.settings.screen_height = self.screen.get_rect().height
pygame.display.set_caption("Alien Invasion")
self.ship = Ship(self)
self.bullets = pygame.sprite.Group()
self.aliens = pygame.sprite.Group()
self._create_fleet()
def run_game(self):
"""Start the main loop for the game."""
while True:
self._check_events()
self.ship.update()
self._update_bullets()
self._update_screen()
def _check_events(self):
"""Respond to keypresses and mouse events."""
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
elif event.type == pygame.KEYDOWN:
self._check_keydown_events(event)
elif event.type == pygame.KEYUP:
self._check_keyup_events(event)
def _check_keydown_events(self, event):
"""Respond to keypresses."""
if event.key == pygame.K_RIGHT:
self.ship.moving_right = True
elif event.key == pygame.K_LEFT:
self.ship.moving_left = True
elif event.key == pygame.K_q:
sys.exit()
elif event.key == pygame.K_SPACE:
self._fire_bullet()
def _check_keyup_events(self, event):
"""Respond to key releases."""
if event.key == pygame.K_RIGHT:
self.ship.moving_right = False
elif event.key == pygame.K_LEFT:
self.ship.moving_left = False
def _fire_bullet(self):
"""Create a new bullet and add it to the bullets group."""
if len(self.bullets) < self.settings.bullets_allowed:
new_bullet = Bullet(self)
self.bullets.add(new_bullet)
def _update_bullets(self):
"""Update position of bullets and get rid of old bullets."""
# Update bullet positions.
self.bullets.update()
# Get rid of bullets that have disappeared.
for bullet in self.bullets.copy():
if bullet.rect.bottom <= 0:
self.bullets.remove(bullet)
def _create_fleet(self):
"""Create the fleet of aliens."""
# Create an alien and find the number of aliens in a row.
# Spacing between each alien is equal to one alien width.
alien = Alien(self)
alien_width, alien_height = alien.rect.size
available_space_x = self.settings.screen_width - (2 * alien_width) # 可以用于放置外星人的水平空间（为了求一行能放多少外星人）
number_aliens_x = available_space_x // (2 * alien_width) # 计算出一行能容纳的外星人个数
# Determine the number of rows of aliens that fit on the screen.
ship_height = self.ship.rect.height
available_space_y = (self.settings.screen_height -
(3 * alien_height) - ship_height) # 可用于放置外星人的垂直空间（为了求能放多少行外星人）
number_rows = available_space_y // (2 * alien_height) # 计算出能容纳多少行外星人
# Create the full fleet of aliens.
for row_number in range(number_rows):
for alien_number in range(number_aliens_x):
self._create_alien(alien_number, row_number) # 调用辅助方法_create_alien，添加外星人到编组aliens
def _create_alien(self, alien_number, row_number):
"""Create an alien and place it in the row."""
alien = Alien(self)
alien_width, alien_height = alien.rect.size
alien.x = alien_width + 2 * alien_width * alien_number
alien.rect.x = alien.x # 每一个alien的属性的x坐标，必须定义x，y坐标，python才知道要将每一个外星人绘制到哪个位置
alien.rect.y = alien.rect.height + 2 * alien.rect.height * row_number # 每一个alien的rect属性y坐标
self.aliens.add(alien)
def _update_screen(self):
"""Update images on the screen, and flip to the new screen."""
self.screen.fill(self.settings.bg_color)
self.ship.blitme()
for bullet in self.bullets.sprites():
bullet.draw_bullet()
self.aliens.draw(self.screen) # 根据定义的alien.rect.x和alien.rect.y，绘制外星人到屏幕上
pygame.display.flip()
if __name__ == '__main__':
# Make a game instance, and run the game.
ai = AlienInvasion()
ai.run_game()
13_2更逼真的星星主程序：
import sys
import pygame
from settings import Settings
from ship import Ship
from bullet import Bullet
from alien import Alien
from random import randint
class AlienInvasion:
"""Overall class to manage game assets and behavior."""
def __init__(self):
"""Initialize the game, and create game resources."""
pygame.init()
self.settings = Settings()
self.screen = pygame.display.set_mode((0, 0), pygame.FULLSCREEN)
self.settings.screen_width = self.screen.get_rect().width
self.settings.screen_height = self.screen.get_rect().height
pygame.display.set_caption("Alien Invasion")
self.ship = Ship(self)
self.bullets = pygame.sprite.Group()
self.aliens = pygame.sprite.Group()
self._create_fleet()
def run_game(self):
"""Start the main loop for the game."""
while True:
self._check_events()
self.ship.update()
self._update_bullets()
self._update_screen()
def _check_events(self):
"""Respond to keypresses and mouse events."""
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
elif event.type == pygame.KEYDOWN:
self._check_keydown_events(event)
elif event.type == pygame.KEYUP:
self._check_keyup_events(event)
def _check_keydown_events(self, event):
"""Respond to keypresses."""
if event.key == pygame.K_RIGHT:
self.ship.moving_right = True
elif event.key == pygame.K_LEFT:
self.ship.moving_left = True
elif event.key == pygame.K_q:
sys.exit()
elif event.key == pygame.K_SPACE:
self._fire_bullet()
def _check_keyup_events(self, event):
"""Respond to key releases."""
if event.key == pygame.K_RIGHT:
self.ship.moving_right = False
elif event.key == pygame.K_LEFT:
self.ship.moving_left = False
def _fire_bullet(self):
"""Create a new bullet and add it to the bullets group."""
if len(self.bullets) < self.settings.bullets_allowed:
new_bullet = Bullet(self)
self.bullets.add(new_bullet)
def _update_bullets(self):
"""Update position of bullets and get rid of old bullets."""
# Update bullet positions.
self.bullets.update()
# Get rid of bullets that have disappeared.
for bullet in self.bullets.copy():
if bullet.rect.bottom <= 0:
self.bullets.remove(bullet)
def _create_fleet(self):
"""Create the fleet of aliens."""
# Create an alien and find the number of aliens in a row.
# Spacing between each alien is equal to one alien width.
alien = Alien(self)
alien_width, alien_height = alien.rect.size
available_space_x = self.settings.screen_width - (2 * alien_width) # 可以用于放置外星人的水平空间（为了求一行能放多少外星人）
number_aliens_x = available_space_x // (2 * alien_width) # 计算出一行能容纳的外星人个数
# Determine the number of rows of aliens that fit on the screen.
ship_height = self.ship.rect.height
available_space_y = (self.settings.screen_height -
(3 * alien_height) - ship_height) # 可用于放置外星人的垂直空间（为了求能放多少行外星人）
number_rows = available_space_y // (2 * alien_height) # 计算出能容纳多少行外星人
# Create the full fleet of aliens.
for row_number in range(number_rows):
for alien_number in range(number_aliens_x):
self._create_alien(alien_number, row_number) # 调用辅助方法_create_alien，添加外星人到编组aliens
def _create_alien(self, alien_number, row_number):
"""Create an alien and place it in the row."""
alien = Alien(self)
alien_width, alien_height = alien.rect.size
alien.x = randint(0,200) + 2 * alien_width * alien_number
alien.rect.x = alien.x # 每一个alien的属性的x坐标，必须定义x，y坐标，python才知道要将每一个外星人绘制到哪个位置
alien.rect.y = randint(0,300) + 3 * alien.rect.height * row_number # 每一个alien的rect属性y坐标
self.aliens.add(alien)
def _update_screen(self):
"""Update images on the screen, and flip to the new screen."""
self.screen.fill(self.settings.bg_color)
self.ship.blitme()
for bullet in self.bullets.sprites():
bullet.draw_bullet()
self.aliens.draw(self.screen) # 根据定义的alien.rect.x和alien.rect.y，绘制外星人到屏幕上
pygame.display.flip()
if __name__ == '__main__':
# Make a game instance, and run the game.
ai = AlienInvasion()
ai.run_game()
alien.py （为了便捷，引用了书中代码，只是将外星人的图片替换成了星星图片，类命名未修改）
import pygame
from pygame.sprite import Sprite
class Alien(Sprite):
"""A class to represent a single alien in the fleet."""
def __init__(self, ai_game):
"""Initialize the alien and set its starting position."""
super().__init__()
self.screen = ai_game.screen
# Load the alien image and set its rect attribute.
self.image = pygame.image.load('images/star.png')
self.rect = self.image.get_rect()
# Start each new alien near the top left of the screen.
self.rect.x = self.rect.width
self.rect.y = self.rect.height
# Store the alien's exact horizontal position.
self.x = float(self.rect.x)
ship.py
import pygame
class Ship:
"""A class to manage the ship."""
def __init__(self, ai_game):
"""Initialize the ship and set its starting position."""
self.screen = ai_game.screen
self.settings = ai_game.settings
self.screen_rect = ai_game.screen.get_rect()
# Load the ship image and get its rect.
self.image = pygame.image.load('images/ship.bmp')
self.rect = self.image.get_rect()
# Start each new ship at the bottom center of the screen.
self.rect.midbottom = self.screen_rect.midbottom
# Store a decimal value for the ship's horizontal position.
self.x = float(self.rect.x)
# Movement flags
self.moving_right = False
self.moving_left = False
def update(self):
"""Update the ship's position based on movement flags."""
# Update the ship's x value, not the rect.
if self.moving_right and self.rect.right < self.screen_rect.right:
self.x += self.settings.ship_speed
if self.moving_left and self.rect.left > 0:
self.x -= self.settings.ship_speed
# Update rect object from self.x.
self.rect.x = self.x
def blitme(self):
"""Draw the ship at its current location."""
self.screen.blit(self.image, self.rect)
settings.py
class Settings:
"""A class to store all settings for Alien Invasion."""
def __init__(self):
"""Initialize the game's settings."""
# Screen settings
self.screen_width = 1200
self.screen_height = 800
self.bg_color = (230, 230, 230)
# Ship settings
self.ship_speed = 1.5
# Bullet settings
self.bullet_speed = 1.0
self.bullet_width = 3
self.bullet_height = 15
self.bullet_color = (60, 60, 60)
self.bullets_allowed = 3
图片命名：star.png，在上述代码文件夹中，新建文件夹images，将图片放置在新文件夹即可
