Where we are on the rocket

▶ ◀

You're on Stage 5 of 10.

The big new idea: lists

Up to now, each "thing" in our game has been one variable: one player, one screen. But you don't shoot just one bullet — you shoot lots of them. How do we keep track of all of them at once?

With a list. A list is exactly what it sounds like: a single variable that holds many items in order. You can add items, remove items, and loop through all of them.

bullets = []        # start with an EMPTY list — no bullets yet
bullets.append(b)   # add a new bullet to the end of the list
for b in bullets:   # loop through every bullet
    b.y -= 10       # move each one up by 10 pixels
bullets.remove(b)   # take a bullet out of the list

🛒 A list is like a shopping basket — you start with an empty basket, you add things in, you can look at every item, and you can take things out.

One shot per press (KEYDOWN)

In Lesson 4 we used pygame.key.get_pressed() because we wanted the player to keep moving as long as you hold the arrow key.

Shooting is different. If we used the same trick for SPACE, a single press would fire 60 bullets a second (one per frame). We want one bullet per press — even if you hold SPACE down.

For "press only once" we use the KEYDOWN event inside the event loop:

for event in pygame.event.get():
    if event.type == pygame.QUIT:
        running = False
    if event.type == pygame.KEYDOWN and event.key == pygame.K_SPACE:
        bullet = pygame.Rect(player.x + 27, player.y, 6, 15)
        bullets.append(bullet)

💡 Rule of thumb: held actions → use key.get_pressed(). One-time actions (shoot, jump, fire) → use KEYDOWN.

Move them up. Remove them when they leave.

Every frame, we slide each bullet up by changing its y:

for b in bullets[:]:
    b.y -= bullet_speed
    if b.y < 0:           # left the top of the screen?
        bullets.remove(b)  # take it out so the list doesn't grow forever

Why bullets[:] instead of just bullets? Because we're removing items while looping through. Modifying a list while you iterate over it confuses Python. bullets[:] makes a quick copy to loop over, while we change the original. Tiny trick, big bug saver.

The code so far

# Stages 1–4 already in place...
import pygame
pygame.init()
WIDTH, HEIGHT = 800, 600
screen = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("Galaxy Defender")
clock = pygame.time.Clock()

YELLOW = (255, 215, 0)
SPACE  = (0, 0, 50)

player = pygame.Rect(370, 520, 60, 40)
player_speed = 5

# 🚀 Cartoon ship (we'll properly explain "def" in Lesson 9 — for
# now, just enjoy your green rectangle becoming a real spaceship.)
def draw_ship(s, x, y):
    pygame.draw.polygon(s, (0, 230, 100),
        [(x+30,y),(x+60,y+40),(x+40,y+30),(x+20,y+30),(x,y+40)])  # hull
    pygame.draw.circle (s, (100, 200, 255), (x+30, y+18), 6)       # cockpit
    pygame.draw.polygon(s, (255, 100, 0),
        [(x+25,y+30),(x+35,y+30),(x+30,y+42)])                     # flame

# Stage 5 — Bullets ✨
bullets = []                # empty list, ready to fill
bullet_speed = 10

running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        if event.type == pygame.KEYDOWN and event.key == pygame.K_SPACE:
            # spawn a new bullet ABOVE the centre of the player
            bullet = pygame.Rect(player.x + 27, player.y, 6, 15)
            bullets.append(bullet)

    keys = pygame.key.get_pressed()
    if keys[pygame.K_LEFT]  and player.x > 0:
        player.x -= player_speed
    if keys[pygame.K_RIGHT] and player.x < WIDTH - 60:
        player.x += player_speed

    # move every bullet up; remove ones that fly off the screen
    for b in bullets[:]:
        b.y -= bullet_speed
        if b.y < 0:
            bullets.remove(b)

    screen.fill(SPACE)
    draw_ship(screen, player.x, player.y)    # 🚀 cartoon ship
    for b in bullets:
        pygame.draw.rect(screen, YELLOW, b)
    pygame.display.flip()
    clock.tick(60)

pygame.quit()

Run it. Move with LEFT/RIGHT. Tap SPACE — a tiny yellow streak flies up. Tap SPACE again — another one. Hold SPACE — just one bullet per press, thanks to KEYDOWN. 🎯

🎮 Want to play with more code? Scroll down to the Lesson 5 Code Library (6 bullet games). Copy any program, paste it into the editor below, and press the green ▶ Run button.

Handouts for this lesson

Print these, keep them open in another tab, or download them to your computer.

📚 Lesson 5 Code Library — 6 brand-new pygame mini-games all about bullets and lists: One Bullet, Press SPACE to Fire, Disappearing Bullets, Bullet Rain, Click to Shoot, Confetti Cannon.

📄 Lesson 5 Code Library (6 bullet games) 🎨 Sprite Bonus (visual polish) 📄 Lesson 4 Code Library 📄 Lesson 3 Code Library 📄 Lesson 2 Code Library 📄 Lesson 1 Code Library

🗺️ The big-picture handouts — keep these by your side for the whole course.

📄 Rocket Ladder 📄 Code Comic 📄 Pixel Cheat Sheet 📄 Code Recipe 🖼️ 6 Parts of a Turtle Program

🤖 Want to try your own idea? Ask an AI like Claude or ChatGPT something like "Write me a short pygame program where pressing SPACE fires a bullet upwards", then paste the code into the Trinket above and click Run.