Reaction Test in Python

Last go

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Average

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Goes

Best

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⌨️ Controls

SPACE or ENTER — that is the whole game
Clicking or tapping the panel works too
R clear the scores • P pause
The panel reacts the moment your finger goes DOWN, not when it comes up.
🎮 Xbox controller? Just plug it in or pair it — the stick and D-pad are the arrow keys, A is SPACE, Menu pauses and View starts again

🎯 How to play

Press once to arm it. The panel says WAIT…
After a random pause the panel turns solid black. Press!
Press before it turns black and it does not count — that is a false start.
The bar chart shows your last eight goes, with your best one filled in.

🏆 What is a good time?

The average grown-up is about 250 ms.
Under 200 ms is genuinely fast.
Under 150 ms usually means you guessed — and got lucky.
Watch the panel, not your hand. And do not blink.

🧑‍💻 This whole game is Python

There is almost no JavaScript on this page. The browser downloaded Pyodide — a complete Python interpreter compiled to WebAssembly — and then ran the .py files in funtime/pylib/. Python does the rules, the maths and the drawing.

File	What it does	Good functions to try re-writing
pylib/reaction_rules.py	The rules: the phases, the delay, the stopwatch	`random_delay`, `update_game`, `press`, `average_time`
pylib/reaction_draw.py	Painting the panel — Python calling the canvas	`panel_words`, `draw_panel`, `draw_history`
pylib/reaction_web.py	The glue: the keyboard and the panel	`do_action`, `on_press`, `frame`

🔍 Compare the two versions. Open lib/reaction-rules.js and pylib/reaction_rules.py side by side — same ideas, two languages.

🛠️ Build it yourself: Build Reaction Test in Python walks you through the functions one at a time.

⚠️ If the game never starts: the page has to read its .py files, which a browser will not do for a page opened straight off your disk. Use the live site, or run python3 -m http.server in the project folder.