alien.py. alien_invasion.py

alien. py

import pygame

from pygame. sprite import Sprite

class Alien(Sprite):

" " " A class to represent a single alien in the fleet. " " "

def __init__(self, ai_settings, screen):

" " " Initialize the alien, and set its starting position. " " "

super(Alien, self). __init__()

self. screen = screen

self. ai_settings = ai_settings

# Load the alien image, and set its rect attribute.

self. image = pygame. image. load('images/alien. bmp')

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 position.

self. x = float(self. rect. x)

def check_edges(self):

" " " Return True if alien is at edge of screen. " " "

screen_rect = self. screen. get_rect()

if self. rect. right> = screen_rect. right:

return True

elifself. rect. left< = 0:

return True

def update(self):

" " " Move the alien right or left. " " "

self. x += (self. ai_settings. alien_speed_factor *

self. ai_settings. fleet_direction)

self. rect. x = self. x

def blitme(self):

" " " Draw the alien at its current location. " " "

self. screen. blit(self. image, self. rect)

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alien_invasion. py

import pygame

from pygame. sprite import Group

from settings import Settings

from game_stats import GameStats

from scoreboard import Scoreboard

from button import Button

from ship import Ship

import game_functions as gf

def run_game():

# Initialize pygame, settings, and screen object.

pygame. init()

ai_settings = Settings()

screen = pygame. display. set_mode(

(ai_settings. screen_width, ai_settings. screen_height))

pygame. display. set_caption(" Alien Invasion" )

# Make the Play button.

play_button = Button(ai_settings, screen, " Play" )

# Create an instance to store game statistics, and a scoreboard.

stats = GameStats(ai_settings)

sb = Scoreboard(ai_settings, screen, stats)

# Set the background color.

bg_color = (230, 230, 230)

# Make a ship, a group of bullets, and a group of aliens.

ship = Ship(ai_settings, screen)

bullets = Group()

aliens = Group()

# Create the fleet of aliens.

gf. create_fleet(ai_settings, screen, ship, aliens)

# Start the main loop for the game.

while True:

gf. check_events(ai_settings, screen, stats, sb, play_button, ship,

aliens, bullets)

if stats. game_active:

ship. update()

gf. update_bullets(ai_settings, screen, stats, sb, ship, aliens,

bullets)

gf. update_aliens(ai_settings, screen, stats, sb, ship, aliens,

bullets)

gf. update_screen(ai_settings, screen, stats, sb, ship, aliens,

bullets, play_button)

run_game()

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