Dojo Defender: Session 2 :: CoderDojo Python & Pygame

Dojo Defender Session 2: Cheatsheet

Mon, 01 Jan 0001 00:00:00 +0000

# Shooting with SPACE def on_key_down(key): global shoot_cooldown if key == keys.SPACE and shoot_cooldown == 0: bullet = Actor('bullet') bullet.x = ship.x bullet.y = ship.y - 20 bullets.append(bullet) shoot_cooldown = 15 # Make bullets move and remove them for bullet in bullets[:]: bullet.y -= 8 if bullet.y < -10: bullets.remove(bullet) # Spawn an enemy def spawn_enemy(): enemy = Actor('enemy_drone') enemy.x = random.randint(30, WIDTH - 30) enemy.y = -30 enemy.speed = random.uniform(1, 3) enemies.append(enemy) # Enemy spawn interval spawn_counter += 1 if spawn_counter >= spawn_interval: spawn_counter = 0 spawn_enemy() # Bullet hits enemy for bullet in bullets[:]: bullet.y -= 8 if bullet.y < -10: bullets.remove(bullet) continue for enemy in enemies[:]: if bullet.colliderect(enemy): bullets.remove(bullet) enemies.remove(enemy) score += 10 break # Waves enemies_destroyed += 1 if enemies_destroyed % 10 == 0: wave += 1 spawn_interval = max(60, spawn_interval - 10) # Sine movement (import math) enemy.x = enemy.start_x + math.sin(timer * 0.03 + enemy.strafe_offset) * 50 # Show wave text if wave_display_timer > 0: screen.draw.text(f"WAVE {wave}!", center=(WIDTH/2, HEIGHT/2), color="yellow", fontsize=60)

Dojo Defender Session 2: Coach notes

Mon, 01 Jan 0001 00:00:00 +0000

Goal of this session After this session a ninja can: Create bullets with on_key_down and a cooldown mechanism Spawn enemy objects and make them move with a sine oscillation Collision detection between bullets and enemies (nested loop) Set up a wave system with increasing difficulty Preparation (30 min before the session) Starter ZIPs ready on USB and on the site: dojo-defender-s3-starter.en.zip and dojo-defender-s3-solution.en.zip. Run the starter yourself once on the dojo room laptop. Ninjas who missed S1: point them to the S1 solution. Schedule (3 hours) This session is an integral part of the normal session 3 (Space Blaster). Use the time as follows:

Dojo Defender Session 2: Demo

Mon, 01 Jan 0001 00:00:00 +0000

How to demo the solution Open a terminal in the project folder. Run: uv run python3 code/sessions/03-space-blaster/dojo-defender-solution/main.py Show: The ship moves left/right with the arrow keys. SPACE fires a bullet up (cooldown visible). Enemies (enemy_drone) spawn at the top and fall with a sine movement. Bullet hits enemy → both disappear, +10 points. Every 10 kills: the wave goes up, enemies spawn faster. Asteroids still keep falling (from S1). A bullet can also hit asteroids (+5 points). Three lives, explosion animation, invincibility, game over — everything from S1 still works.