up to pg 259

alien.py

@@ -0,0 +1,22 @@
+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):
+ """Init the alien & set it's starting position"""
+ super().__init__()
+ self.screen = ai_game.screen
+ self.screen = ai_game.screen
+
+ # Load the alien image and set it's rect attrib 
+ self.image = pygame.image.load("images/alien.bmp")
+ self.rect = self.image.get_rect()
+
+ # Start each new alien near the top left of 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)

alien_invasion.py

@@ -2,6 +2,8 @@
 import pygame
 from settings import Settings
 from ship import Ship
+from bullet import Bullet
+from alien import Alien
 
 
 class AlienInvasion:
@@ -19,6 +21,10 @@ def __init__(self) -> None:
  pygame.display.set_caption("Alien Invasion")
 
  self.ship = Ship(self)
+ self.bullets = pygame.sprite.Group()
+ self.aliens = pygame.sprite.Group()
+
+ self._create_fleet()
 
  # Set the background color.
  self.bg_color = (230, 230, 230)
@@ -28,6 +34,7 @@ def run_game(self):
  while True:
  self._check_events()
  self.ship.update()
+ self._update_bullets()
  self._update_screen()
  self.clock.tick(60)
 
@@ -51,6 +58,8 @@ def _check_keydown_events(self, event):
  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"""
@@ -59,14 +68,40 @@ def _check_keyup_events(self, event):
  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 & delete old bullets."""
+ # Update bullet positions.
+ self.bullets.update()
+
+ # Delete bullets at top of screen
+ for bullet in self.bullets.copy():
+ if bullet.rect.bottom <= 0:
+ self.bullets.remove(bullet)
+ # print(len(self.bullets)) 
+
+ def _create_fleet(self):
+ """Create the fleet of aliens"""
+ # Make an alien
+ alien = Alien(self)
+ 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)
+ for bullet in self.bullets.sprites():
+ bullet.draw_bullet()
  self.ship.blitme()
+ self.aliens.draw(self.screen)
 
  pygame.display.flip()
 
-
 if __name__ == "__main__":
  # Make a game instance & run the game.
  ai = AlienInvasion()

bullet.py

@@ -1,5 +1,5 @@
 import pygame
-from pygame.sprite import _Group, Sprite
+from pygame.sprite import Sprite
 
 class Bullet(Sprite):
  """A class to manage bullets fired from the ship"""

settings.py

@@ -16,3 +16,4 @@ def __init__(self) -> None:
  self.bullet_width = 3
  self.bullet_height = 15
  self.bullet_color = (60, 60, 60)
+ self.bullets_allowed = 5