[PyGame] multiple hits !

[tyler]

im trying to get my aliens to get hit multiple times before dissapearing, i have given the aliens 2 hp and my bullet dmg is 1 so it should take two hits so far ive just made the enemies imortal, lol, can somone please help !!!!!

import sys

from time import sleep

import pygame

from bullet import Bullet

from alien import Alien

def get_number_aliens_x(ai_settings, alien_width):
    """determine the number of aliens that fit in a row"""
    avaliable_space_x = ai_settings.screen_width - 2 * alien_width
    number_aliens_x = int(avaliable_space_x / (2 * alien_width))
    return number_aliens_x

def get_number_rows(ai_settings, ship_height, alien_height):
    """ determine the number of rows of aliens fit on the screen"""
    avaliable_space_y = (ai_settings.screen_height -
                             (3 * alien_height) - ship_height)
    number_rows = int(avaliable_space_y / (2 * alien_height))
    return number_rows

def create_alien(ai_settings, screen, aliens, alien_number, row_number):
    """create an alien and place it in a row"""
    alien = Alien(ai_settings, screen)
    alien_width = alien.rect.width
    alien.x = alien_width + 2 * alien_width * alien_number
    alien.rect.x = alien.x
    alien.rect.y = alien.rect.height + 2 * alien.rect.height * row_number
    aliens.add(alien)

def create_fleet(ai_settings, screen, ship, aliens):
    """creates a full fleet of aliens"""
    #create an alien and find the number of aliens in a row
    alien = Alien(ai_settings, screen)
    number_aliens_x = get_number_aliens_x(ai_settings, alien.rect.width)
    number_rows = get_number_rows(ai_settings, ship.rect.height,
        alien.rect.height)
    
  #creates the fleet of aliens
    for row_number in range(number_rows):
        for alien_number in range(number_aliens_x):
            create_alien(ai_settings, screen, aliens, alien_number,
                         row_number)

def check_keydown_events(event, ai_settings, screen, ship, bullets):
    """responds to keypresses"""
    if event.key == pygame.K_RIGHT:
        ship.moving_right = True
    elif event.key == pygame.K_LEFT:
        ship.moving_left = True
    elif event.key == pygame.K_SPACE:
        effect = pygame.mixer.Sound('sounds/shot.wav')
        effect.play()
        fire_bullet(ai_settings, screen, ship, bullets)
    elif event.key == pygame.K_q:
        sys.exit()

def fire_bullet(ai_settings, screen, ship, bullets):
    """fire a bullet if limit not reached yet"""
        # create a new bullet and add it to the bullets group
    if len(bullets) < ai_settings.bullets_allowed:
        new_bullet = Bullet(ai_settings, screen, ship)
        bullets.add(new_bullet)

def check_keyup_events(event, ship):
    """responds to key presses"""
    if event.key == pygame.K_RIGHT:
        ship.moving_right = False
    elif event.key == pygame.K_LEFT:
        ship.moving_left = False


#watch for keyboard and mouse events
def check_events(ai_settings, screen, stats, sb, play_button, ship, aliens,
                 bullets):
    """ responds to key and mouse events """
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
        elif event.type == pygame.KEYDOWN:
            check_keydown_events(event,ai_settings, screen, ship, bullets)
        elif event.type == pygame.KEYUP:
            check_keyup_events(event, ship)
        elif event.type == pygame.MOUSEBUTTONDOWN:
            mouse_x, mouse_y = pygame.mouse.get_pos()
            check_play_button(ai_settings, screen, stats, sb, play_button,
                              ship, aliens, bullets, mouse_x, mouse_y)

def check_play_button(ai_settings, screen, stats, sb, play_button, ship, aliens
                      , bullets, mouse_x, mouse_y):
    """start a new game when the player clicks play"""
    button_clicked = play_button.rect.collidepoint(mouse_x, mouse_y)
    if button_clicked and not stats.game_active:

        #reset the game settings
        ai_settings.initialize_dynamic_settings()

        #hide mouse cursor
        pygame.mouse.set_visible(False)
        
        #reset the game stats
        stats.reset_stats()
        stats.game_active = True

        #reser the scoreboard images
        sb.prep_score()
        sb.prep_high_score()
        sb.prep_level()
        sb.prep_ships()

        #empty the list of aliens and bullets
        aliens.empty()
        bullets.empty()

        #create new fleet and center the ship
        create_fleet(ai_settings, screen, ship, aliens)
        ship.center_ship()
            
def update_screen(ai_settings, screen, stats, sb, ship, aliens, bullets,
                  play_button):
    """updates images on the screen and flip to the new screen"""
    #redraw the screen during each pass through the loop.
    screen.fill(ai_settings.bg_colour)
    
    #redraw all bullets behind ship and aliens
    for bullet in bullets.sprites():
        bullet.draw_bullets()
    ship.blitme()
    aliens.draw(screen)
    
    #redraw all bullets behind ship and aliens
    for bullet in bullets.sprites():
        bullet.draw_bullets()

    #draw score infomation
    sb.show_score()

    #draw the play button if the game is inactive
    if not stats.game_active:
        play_button.draw_button()

    
    #make the most recently drawn screen visable.
    pygame.display.flip()

def update_bullets(ai_settings, screen, stats, sb, ship, aliens, bullets):
    """updates position of bullets and gets rid of old ones"""
    # update bullet positions
    bullets.update()
    
    # gets rid of bullets that have dissapeared
    for bullet in bullets.copy():
        if bullet.rect.bottom <= 0:
            bullets.remove(bullet)

    check_bullet_alien_collisions(ai_settings, screen, stats, sb,
                                  ship, aliens, bullets)

def check_bullet_alien_collisions(ai_settings, screen, stats, sb,
                                  ship, aliens, bullets):
    """respond to bullet-alien collisions"""
    #remove any bullets and aliens that have collided
    collisions = pygame.sprite.groupcollide(bullets, aliens, True, False)
    if collisions:
        for aliens in collisions.values():
            ai_settings.alien_hp -= ai_settings.bullet_dmg
            if ai_settings.alien_hp <=0:
                
                stats.score += ai_settings.alien_points * len(aliens)
                sb.prep_score()
                check_high_score(stats, sb)
                
            else:
                sb.prep_score()
                check_high_score(stats, sb)

    if len(aliens) == 0:
        #if fleet is destroyed start a new level.
        bullets.empty()
        ai_settings.increase_speed()

        #increase level
        stats.level += 1
        sb.prep_level()
        
        create_fleet(ai_settings, screen, ship, aliens)



def check_fleet_edges(ai_settings, aliens):
    """respond appropriately in any aliens have reached an edge """
    for alien in aliens.sprites():
        if alien.check_edges():
            change_fleet_direction(ai_settings, aliens)
            break

def change_fleet_direction(ai_settings, aliens):
    """drop the entire fleet and change the fleet's direction"""
    for alien in aliens.sprites():
        alien.rect.y += ai_settings.fleet_drop_speed
    ai_settings.fleet_direction *= -1

def ship_hit(ai_settings, stats, sb, screen, ship, aliens, bullets):
    """respond to ship being hit by an alien"""
    if stats.ships_left > 0:
        #decrement ships_left
        stats.ships_left -= 1

        #update scoreboard
        sb.prep_ships()

        #empty the list of aliens and bullets
        aliens.empty()
        bullets.empty()

        #create new fleet and centre the ship
        create_fleet(ai_settings, screen, ship, aliens)
        ship.center_ship()

        #pause
        sleep(0.5)
    else:
        stats.game_active = False
        pygame.mouse.set_visible(True)

def check_aliens_bottom(ai_settings, stats, sb, screen, ship, aliens, bullets):
    """check if any aliens have reached the bottom of the screen """
    screen_rect = screen.get_rect()
    for alien in aliens.sprites():
        if alien.rect.bottom >= screen_rect.bottom:
            #treat this the same as the ship getting hit
            ship_hit(ai_settings, stats, sb, screen, ship, aliens, bullets)
            break

def update_aliens(ai_settings, stats, sb,  screen, ship, aliens, bullets):
    """
check if the fleet is at an edge,
and then update the positions of all the aliens in the fleet
    """
    check_fleet_edges(ai_settings, aliens)
    aliens.update()
    
    #looks for alien-ship collisions
    if pygame.sprite.spritecollideany(ship, aliens):
        ship_hit(ai_settings, stats, sb, screen, ship, aliens, bullets)

    #looks for aliens hitting the bottom of the screen
    check_aliens_bottom(ai_settings, stats, sb, screen, ship, aliens, bullets)

def check_high_score(stats, sb):
    """check to see if there is a new highscore"""
    if stats.score > stats.high_score:
        stats.high_score = stats.score
        sb.prep_high_score()