Easy Learn Python Space Shooter game building using Pygame

Hi,  coders! Today I will show you guys, how to build one of the most popular games that we used to play during our kids & used to think to built i.e “Space Shooter”. So, today we have written a blog on how to easily build python space shooter game using pygame. Following are steps to build space shooter game,

Requirements:

• A PC with any OS installed in it. You can choose Mac Book, Asus Zenbook, Dell Inspiron, or any Pc with a high processor.
• The latest version of Python3 which can be easily downloaded from https://www.python.org/downloads/[For installing you can check this blog]
• A good Code IDE [ Prefer using VS Code or Atom]
• Your focus

Tutorial:

• Firstly, open your cmd[Command Prompt] and type the following command after installing python from https://pypi.org/project/pygame/

1. pip install pygame
2. pip install random2

• Secondly, copy the following codes provided along with resources that you can get in the download button below.
• Lastly, run the python code with python main.py command.[Here, main.py is the file name]. That’s it!

Source Code:

from __future__ import division
import pygame
import random
from os import path

## assets folder
img_dir = path.join(path.dirname(__file__), 'assets')
sound_folder = path.join(path.dirname(__file__), 'sounds')

###############################
## to be placed in "constant.py" later
WIDTH = 480
HEIGHT = 600
FPS = 60
POWERUP_TIME = 5000
BAR_LENGTH = 100
BAR_HEIGHT = 10

# Define Colors
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
YELLOW = (255, 255, 0)
###############################

###############################
## to placed in "__init__.py" later
## initialize pygame and create window
pygame.init()
pygame.mixer.init()  # For sound
screen = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("Space Shooter")
clock = pygame.time.Clock()  # For syncing the FPS
###############################

font_name = pygame.font.match_font('arial')


def main_menu():
    global screen

    menu_song = pygame.mixer.music.load(path.join(sound_folder, "menu.ogg"))
    pygame.mixer.music.play(-1)

    title = pygame.image.load(path.join(img_dir, "main.png")).convert()
    title = pygame.transform.scale(title, (WIDTH, HEIGHT), screen)

    screen.blit(title, (0, 0))
    pygame.display.update()

    while True:
        ev = pygame.event.poll()
        if ev.type == pygame.KEYDOWN:
            if ev.key == pygame.K_RETURN:
                break
            elif ev.key == pygame.K_q:
                pygame.quit()
                quit()
        elif ev.type == pygame.QUIT:
                pygame.quit()
                quit()
        else:
            draw_text(screen, "Press [ENTER] To Begin", 30, WIDTH/2, HEIGHT/2)
            draw_text(screen, "or [Q] To Quit", 30, WIDTH/2, (HEIGHT/2)+40)
            pygame.display.update()

    #pygame.mixer.music.stop()
    ready = pygame.mixer.Sound(path.join(sound_folder, 'getready.ogg'))
    ready.play()
    screen.fill(BLACK)
    draw_text(screen, "GET READY!", 40, WIDTH/2, HEIGHT/2)
    pygame.display.update()


def draw_text(surf, text, size, x, y):
    ## selecting a cross platform font to display the score
    font = pygame.font.Font(font_name, size)
    # True denotes the font to be anti-aliased
    text_surface = font.render(text, True, WHITE)
    text_rect = text_surface.get_rect()
    text_rect.midtop = (x, y)
    surf.blit(text_surface, text_rect)


def draw_shield_bar(surf, x, y, pct):
    # if pct < 0:
    #     pct = 0
    pct = max(pct, 0)
    ## moving them to top
    # BAR_LENGTH = 100
    # BAR_HEIGHT = 10
    fill = (pct / 100) * BAR_LENGTH
    outline_rect = pygame.Rect(x, y, BAR_LENGTH, BAR_HEIGHT)
    fill_rect = pygame.Rect(x, y, fill, BAR_HEIGHT)
    pygame.draw.rect(surf, GREEN, fill_rect)
    pygame.draw.rect(surf, WHITE, outline_rect, 2)


def draw_lives(surf, x, y, lives, img):
    for i in range(lives):
        img_rect = img.get_rect()
        img_rect.x = x + 30 * i
        img_rect.y = y
        surf.blit(img, img_rect)


def newmob():
    mob_element = Mob()
    all_sprites.add(mob_element)
    mobs.add(mob_element)


class Explosion(pygame.sprite.Sprite):
    def __init__(self, center, size):
        pygame.sprite.Sprite.__init__(self)
        self.size = size
        self.image = explosion_anim[self.size][0]
        self.rect = self.image.get_rect()
        self.rect.center = center
        self.frame = 0
        self.last_update = pygame.time.get_ticks()
        self.frame_rate = 75

    def update(self):
        now = pygame.time.get_ticks()
        if now - self.last_update > self.frame_rate:
            self.last_update = now
            self.frame += 1
            if self.frame == len(explosion_anim[self.size]):
                self.kill()
            else:
                center = self.rect.center
                self.image = explosion_anim[self.size][self.frame]
                self.rect = self.image.get_rect()
                self.rect.center = center


class Player(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        ## scale the player img down
        self.image = pygame.transform.scale(player_img, (50, 38))
        self.image.set_colorkey(BLACK)
        self.rect = self.image.get_rect()
        self.radius = 20
        self.rect.centerx = WIDTH / 2
        self.rect.bottom = HEIGHT - 10
        self.speedx = 0
        self.shield = 100
        self.shoot_delay = 250
        self.last_shot = pygame.time.get_ticks()
        self.lives = 3
        self.hidden = False
        self.hide_timer = pygame.time.get_ticks()
        self.power = 1
        self.power_timer = pygame.time.get_ticks()

    def update(self):
        ## time out for powerups
        if self.power >= 2 and pygame.time.get_ticks() - self.power_time > POWERUP_TIME:
            self.power -= 1
            self.power_time = pygame.time.get_ticks()

        ## unhide
        if self.hidden and pygame.time.get_ticks() - self.hide_timer > 1000:
            self.hidden = False
            self.rect.centerx = WIDTH / 2
            self.rect.bottom = HEIGHT - 30

        self.speedx = 0  # makes the player static in the screen by default.
        # then we have to check whether there is an event hanlding being done for the arrow keys being
        ## pressed

        ## will give back a list of the keys which happen to be pressed down at that moment
        keystate = pygame.key.get_pressed()
        if keystate[pygame.K_LEFT]:
            self.speedx = -5
        elif keystate[pygame.K_RIGHT]:
            self.speedx = 5

        #Fire weapons by holding spacebar
        if keystate[pygame.K_SPACE]:
            self.shoot()

        ## check for the borders at the left and right
        if self.rect.right > WIDTH:
            self.rect.right = WIDTH
        if self.rect.left < 0:
            self.rect.left = 0

        self.rect.x += self.speedx

    def shoot(self):
        ## to tell the bullet where to spawn
        now = pygame.time.get_ticks()
        if now - self.last_shot > self.shoot_delay:
            self.last_shot = now
            if self.power == 1:
                bullet = Bullet(self.rect.centerx, self.rect.top)
                all_sprites.add(bullet)
                bullets.add(bullet)
                shooting_sound.play()
            if self.power == 2:
                bullet1 = Bullet(self.rect.left, self.rect.centery)
                bullet2 = Bullet(self.rect.right, self.rect.centery)
                all_sprites.add(bullet1)
                all_sprites.add(bullet2)
                bullets.add(bullet1)
                bullets.add(bullet2)
                shooting_sound.play()

            """ MOAR POWAH """
            if self.power >= 3:
                bullet1 = Bullet(self.rect.left, self.rect.centery)
                bullet2 = Bullet(self.rect.right, self.rect.centery)
                # Missile shoots from center of ship
                missile1 = Missile(self.rect.centerx, self.rect.top)
                all_sprites.add(bullet1)
                all_sprites.add(bullet2)
                all_sprites.add(missile1)
                bullets.add(bullet1)
                bullets.add(bullet2)
                bullets.add(missile1)
                shooting_sound.play()
                missile_sound.play()

    def powerup(self):
        self.power += 1
        self.power_time = pygame.time.get_ticks()

    def hide(self):
        self.hidden = True
        self.hide_timer = pygame.time.get_ticks()
        self.rect.center = (WIDTH / 2, HEIGHT + 200)


# defines the enemies
class Mob(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image_orig = random.choice(meteor_images)
        self.image_orig.set_colorkey(BLACK)
        self.image = self.image_orig.copy()
        self.rect = self.image.get_rect()
        self.radius = int(self.rect.width * .90 / 2)
        self.rect.x = random.randrange(0, WIDTH - self.rect.width)
        self.rect.y = random.randrange(-150, -100)
        # for randomizing the speed of the Mob
        self.speedy = random.randrange(5, 20)

        ## randomize the movements a little more
        self.speedx = random.randrange(-3, 3)

        ## adding rotation to the mob element
        self.rotation = 0
        self.rotation_speed = random.randrange(-8, 8)
        # time when the rotation has to happen
        self.last_update = pygame.time.get_ticks()

    def rotate(self):
        time_now = pygame.time.get_ticks()
        if time_now - self.last_update > 50:  # in milliseconds
            self.last_update = time_now
            self.rotation = (self.rotation + self.rotation_speed) % 360
            new_image = pygame.transform.rotate(self.image_orig, self.rotation)
            old_center = self.rect.center
            self.image = new_image
            self.rect = self.image.get_rect()
            self.rect.center = old_center

    def update(self):
        self.rotate()
        self.rect.x += self.speedx
        self.rect.y += self.speedy
        ## now what if the mob element goes out of the screen

        if (self.rect.top > HEIGHT + 10) or (self.rect.left < -25) or (self.rect.right > WIDTH + 20):
            self.rect.x = random.randrange(0, WIDTH - self.rect.width)
            self.rect.y = random.randrange(-100, -40)
            # for randomizing the speed of the Mob
            self.speedy = random.randrange(1, 8)

## defines the sprite for Powerups


class Pow(pygame.sprite.Sprite):
    def __init__(self, center):
        pygame.sprite.Sprite.__init__(self)
        self.type = random.choice(['shield', 'gun'])
        self.image = powerup_images[self.type]
        self.image.set_colorkey(BLACK)
        self.rect = self.image.get_rect()
        ## place the bullet according to the current position of the player
        self.rect.center = center
        self.speedy = 2

    def update(self):
        """should spawn right in front of the player"""
        self.rect.y += self.speedy
        ## kill the sprite after it moves over the top border
        if self.rect.top > HEIGHT:
            self.kill()


## defines the sprite for bullets
class Bullet(pygame.sprite.Sprite):
    def __init__(self, x, y):
        pygame.sprite.Sprite.__init__(self)
        self.image = bullet_img
        self.image.set_colorkey(BLACK)
        self.rect = self.image.get_rect()
        ## place the bullet according to the current position of the player
        self.rect.bottom = y
        self.rect.centerx = x
        self.speedy = -10

    def update(self):
        """should spawn right in front of the player"""
        self.rect.y += self.speedy
        ## kill the sprite after it moves over the top border
        if self.rect.bottom < 0:
            self.kill()

        ## now we need a way to shoot
        ## lets bind it to "spacebar".
        ## adding an event for it in Game loop

## FIRE ZE MISSILES


class Missile(pygame.sprite.Sprite):
    def __init__(self, x, y):
        pygame.sprite.Sprite.__init__(self)
        self.image = missile_img
        self.image.set_colorkey(BLACK)
        self.rect = self.image.get_rect()
        self.rect.bottom = y
        self.rect.centerx = x
        self.speedy = -10

    def update(self):
        """should spawn right in front of the player"""
        self.rect.y += self.speedy
        if self.rect.bottom < 0:
            self.kill()


###################################################
## Load all game images

background = pygame.image.load(path.join(img_dir, 'starfield.png')).convert()
background_rect = background.get_rect()
## ^^ draw this rect first

player_img = pygame.image.load(
    path.join(img_dir, 'playerShip1_orange.png')).convert()
player_mini_img = pygame.transform.scale(player_img, (25, 19))
player_mini_img.set_colorkey(BLACK)
bullet_img = pygame.image.load(path.join(img_dir, 'laserRed16.png')).convert()
missile_img = pygame.image.load(
    path.join(img_dir, 'missile.png')).convert_alpha()
# meteor_img = pygame.image.load(path.join(img_dir, 'meteorBrown_med1.png')).convert()
meteor_images = []
meteor_list = [
    'meteorBrown_big1.png',
    'meteorBrown_big2.png',
    'meteorBrown_med1.png',
    'meteorBrown_med3.png',
    'meteorBrown_small1.png',
    'meteorBrown_small2.png',
    'meteorBrown_tiny1.png'
]

for image in meteor_list:
    meteor_images.append(pygame.image.load(
        path.join(img_dir, image)).convert())

## meteor explosion
explosion_anim = {}
explosion_anim['lg'] = []
explosion_anim['sm'] = []
explosion_anim['player'] = []
for i in range(9):
    filename = 'regularExplosion0{}.png'.format(i)
    img = pygame.image.load(path.join(img_dir, filename)).convert()
    img.set_colorkey(BLACK)
    ## resize the explosion
    img_lg = pygame.transform.scale(img, (75, 75))
    explosion_anim['lg'].append(img_lg)
    img_sm = pygame.transform.scale(img, (32, 32))
    explosion_anim['sm'].append(img_sm)

    ## player explosion
    filename = 'sonicExplosion0{}.png'.format(i)
    img = pygame.image.load(path.join(img_dir, filename)).convert()
    img.set_colorkey(BLACK)
    explosion_anim['player'].append(img)

## load power ups
powerup_images = {}
powerup_images['shield'] = pygame.image.load(
    path.join(img_dir, 'shield_gold.png')).convert()
powerup_images['gun'] = pygame.image.load(
    path.join(img_dir, 'bolt_gold.png')).convert()


###################################################


###################################################
### Load all game sounds
shooting_sound = pygame.mixer.Sound(path.join(sound_folder, 'pew.wav'))
missile_sound = pygame.mixer.Sound(path.join(sound_folder, 'rocket.ogg'))
expl_sounds = []
for sound in ['expl3.wav', 'expl6.wav']:
    expl_sounds.append(pygame.mixer.Sound(path.join(sound_folder, sound)))
## main background music
#pygame.mixer.music.load(path.join(sound_folder, 'tgfcoder-FrozenJam-SeamlessLoop.ogg'))
pygame.mixer.music.set_volume(0.2)  # simmered the sound down a little

player_die_sound = pygame.mixer.Sound(path.join(sound_folder, 'rumble1.ogg'))
###################################################

## TODO: make the game music loop over again and again. play(loops=-1) is not working
# Error :
# TypeError: play() takes no keyword arguments
#pygame.mixer.music.play()

#############################
## Game loop
running = True
menu_display = True
while running:
    if menu_display:
        main_menu()
        pygame.time.wait(3000)

        #Stop menu music
        pygame.mixer.music.stop()
        #Play the gameplay music
        pygame.mixer.music.load(
            path.join(sound_folder, 'tgfcoder-FrozenJam-SeamlessLoop.ogg'))
        # makes the gameplay sound in an endless loop
        pygame.mixer.music.play(-1)

        menu_display = False

        ## group all the sprites together for ease of update
        all_sprites = pygame.sprite.Group()
        player = Player()
        all_sprites.add(player)

        ## spawn a group of mob
        mobs = pygame.sprite.Group()
        for i in range(8):  # 8 mobs
            # mob_element = Mob()
            # all_sprites.add(mob_element)
            # mobs.add(mob_element)
            newmob()

        ## group for bullets
        bullets = pygame.sprite.Group()
        powerups = pygame.sprite.Group()

        #### Score board variable
        score = 0

    #1 Process input/events
    clock.tick(FPS)  # will make the loop run at the same speed all the time
    # gets all the events which have occured till now and keeps tab of them.
    for event in pygame.event.get():
        ## listening for the the X button at the top
        if event.type == pygame.QUIT:
            running = False

        ## Press ESC to exit game
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_ESCAPE:
                running = False
        # ## event for shooting the bullets
        # elif event.type == pygame.KEYDOWN:
        #     if event.key == pygame.K_SPACE:
        #         player.shoot()      ## we have to define the shoot()  function

    #2 Update
    all_sprites.update()

    ## check if a bullet hit a mob
    ## now we have a group of bullets and a group of mob
    hits = pygame.sprite.groupcollide(mobs, bullets, True, True)
    ## now as we delete the mob element when we hit one with a bullet, we need to respawn them again
    ## as there will be no mob_elements left out
    for hit in hits:
        score += 50 - hit.radius  # give different scores for hitting big and small metoers
        random.choice(expl_sounds).play()
        # m = Mob()
        # all_sprites.add(m)
        # mobs.add(m)
        expl = Explosion(hit.rect.center, 'lg')
        all_sprites.add(expl)
        if random.random() > 0.9:
            pow = Pow(hit.rect.center)
            all_sprites.add(pow)
            powerups.add(pow)
        newmob()  # spawn a new mob

    ## ^^ the above loop will create the amount of mob objects which were killed spawn again
    #########################

    ## check if the player collides with the mob
    # gives back a list, True makes the mob element disappear
    hits = pygame.sprite.spritecollide(
        player, mobs, True, pygame.sprite.collide_circle)
    for hit in hits:
        player.shield -= hit.radius * 2
        expl = Explosion(hit.rect.center, 'sm')
        all_sprites.add(expl)
        newmob()
        if player.shield <= 0:
            player_die_sound.play()
            death_explosion = Explosion(player.rect.center, 'player')
            all_sprites.add(death_explosion)
            # running = False     ## GAME OVER 3:D
            player.hide()
            player.lives -= 1
            player.shield = 100

    ## if the player hit a power up
    hits = pygame.sprite.spritecollide(player, powerups, True)
    for hit in hits:
        if hit.type == 'shield':
            player.shield += random.randrange(10, 30)
            if player.shield >= 100:
                player.shield = 100
        if hit.type == 'gun':
            player.powerup()

    ## if player died and the explosion has finished, end game
    if player.lives == 0 and not death_explosion.alive():
        running = False
        # menu_display = True
        # pygame.display.update()

    #3 Draw/render
    screen.fill(BLACK)
    ## draw the stargaze.png image
    screen.blit(background, background_rect)

    all_sprites.draw(screen)
    # 10px down from the screen
    draw_text(screen, str(score), 18, WIDTH / 2, 10)
    draw_shield_bar(screen, 5, 5, player.shield)

    # Draw lives
    draw_lives(screen, WIDTH - 100, 5, player.lives, player_mini_img)

    ## Done after drawing everything to the screen
    pygame.display.flip()

pygame.quit()

Conclusion:

Though all the instructions are given easily but to avoid any issue while running the Dino Run game following the instruction carefully. If any issue occurs contact us by emailing us. Also, let us know whether this blog helps you or not in the comment section below. Thank you!