Lesson 21: High Scores + Level + Ships Remaining (Matthes Ch 14 §5-7)
Learning Intentions
- Add the final HUD pieces — high score (saved across runs), current level, ship-icon lives display.
Success Criteria
- My high score persists after I close + reopen the game.
- Current level displays under the score.
- Remaining lives show as ship icons in the top-left.
📍 Do Now — Error of the Day
Your Alien Invasion is feature-complete except for one thing: when you close the game, your top score VANISHES. Who remembers what the highest score was last lesson?
👁 I Do — Teacher Demo
Live-code high score persistence. json.dump(self.stats.high_score, open('high_score.json', 'w')). Load with try/except FileNotFoundError. Extend Scoreboard with prep_high_score, prep_level, and prep_ships (reuses Ship as life icons).
🤝 We Do — Build Together
Class adds all 3 HUD elements. Full HUD: score top-right, high score top-centre, level under score, lives top-left as ship icons.
🚀 You Do — Your Turn
Beat your own high score. Close the game — reopen — check that high_score.json persists. Open it in VS Code to see the number. Arcade quests cover json file I/O.
- Add self.high_score = 0 + load from high_score.json in GameStats
- Add _save_high_score() using json.dump
- Extend Scoreboard: prep_high_score, prep_level, prep_ships (reuses Ship class)
- Update high score on every score change
- In show_score: blit all four (score, high_score, level, ships)
🎮 Practice Quests — work through these
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Three tiers — pick yours
Support
prep_* methods scaffolded; json helpers pre-written
Core
build from scratch
Extension
top 5 leaderboard
Extensions
- Store TOP 5 high scores in a list instead of just one.
- Flash 'NEW HIGH SCORE!' briefly when it's beaten.
📝 Exit Ticket — Coding Journal
Journal: describe what's in your high_score.json file. Why is it a text file, not binary? What else could we save there?
Evidence of Learning
Full HUD: score + high score + level + ship icons. high_score.json persists across runs.