1.  
2.  
3. from pygame import *
4. from random import randint
5.  
6.  
7. #background music
8. mixer.init()
9. mixer.music.load('space.ogg')
10. mixer.music.play()
11. fire_sound = mixer.Sound('fire.ogg')
12.  
13.  
14. #fonts and captions
15. font.init()
16. font2 = font.Font(None, 36)
17.  
18.  
19. #we need the following images:
20. img_back = "galaxy.jpg" # game background
21. img_hero = "rocket.png" # hero
22. img_enemy = "ufo.png" # enemy
23.  
24.  
25. score = 0 #ships destroyed
26. lost = 0 #ships missed
27.  
28.  
29. #parent class for other sprites
30. class GameSprite(sprite.Sprite):
31.  #class constructor
32.    def __init__(self, player_image, player_x, player_y, size_x, size_y, player_speed):
33.        #Call for the class (Sprite) constructor:
34.        sprite.Sprite.__init__(self)
35.  
36.  
37.        #every sprite must store the image property
38.        self.image = transform.scale(image.load(player_image), (size_x, size_y))
39.        self.speed = player_speed
40.  
41.  
42.        #every sprite must have the rect property that represents the rectangle it is fitted in
43.        self.rect = self.image.get_rect()
44.        self.rect.x = player_x
45.        self.rect.y = player_y
46.  #method drawing the character on the window
47.    def reset(self):
48.        window.blit(self.image, (self.rect.x, self.rect.y))
49.  
50.  
51. #main player class
52. class Player(GameSprite):
53.    #method to control the sprite with arrow keys
54.    def update(self):
55.        keys = key.get_pressed()
56.        if keys[K_LEFT] and self.rect.x > 5:
57.            self.rect.x -= self.speed
58.        if keys[K_RIGHT] and self.rect.x < win_width - 80:
59.            self.rect.x += self.speed
60.  #method to "shoot" (use the player position to create a bullet there)
61.    def fire(self):
62.        pass
63.  
64.  
65. #enemy sprite class  
66. class Enemy(GameSprite):
67.    #enemy movement
68.    def update(self):
69.        self.rect.y += self.speed
70.        global lost
71.        #disappears upon reaching the screen edge
72.        if self.rect.y > win_height:
73.            self.rect.x = randint(80, win_width - 80)
74.            self.rect.y = 0
75.            lost = lost + 1
76.  
77.  
78. #create a small window
79. win_width = 700
80. win_height = 500
81. display.set_caption("Shooter")
82. window = display.set_mode((win_width, win_height))
83. background = transform.scale(image.load(img_back), (win_width, win_height))
84.  
85.  
86. #create sprites
87. ship = Player(img_hero, 5, win_height - 100, 80, 100, 10)
88.  
89.  
90. monsters = sprite.Group()
91. for i in range(1, 6):
92.    monster = Enemy(img_enemy, randint(80, win_width - 80), -40, 80, 50, randint(1, 5))
93.    monsters.add(monster)
94.  
95.  
96. #the "game is over" variable: as soon as True is there, sprites stop working in the main loop
97. finish = False
98. #Main game loop:
99. run = True #the flag is reset by the window close button
100. while run:
101.    #"Close" button press event
102.    for e in event.get():
103.        if e.type == QUIT:
104.            run = False
105.  
106.  
107.    if not finish:
108.        #update the background
109.        window.blit(background,(0,0))
110.  
111.  
112.        #write text on the screen
113.        text = font2.render("Score: " + str(score), 1, (255, 255, 255))
114.        window.blit(text, (10, 20))
115.  
116.  
117.        text_lose = font2.render("Missed: " + str(lost), 1, (255, 255, 255))
118.        window.blit(text_lose, (10, 50))
119.  
120.  
121.        #launch sprite movements
122.        ship.update()
123.        monsters.update()
124.  
125.  
126.        #update them in a new location in each loop iteration
127.        ship.reset()
128.        monsters.draw(window)
129.  
130.  
131.        display.update()
132.    #the loop is executed each 0.05 sec
133.    time.delay(50)