Python 3 · runs in your browser
Learn Python by writing Python.
108 lessons of read-a-little, write-a-lot, every one of them free. Real CPython runs inside this page through WebAssembly, so there is nothing to install and nothing to configure — and your code never leaves your machine.
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On iPhone or iPad? The same lessons work offline in the app.
This editor is live. Change it, run it.
Read the idea
Every lesson opens with a short explanation and a worked example — no video, no filler.
Write the code
A real editor sits beside the instructions. Run it as often as you like; mistakes cost nothing.
Get it checked
Hidden tests grade what you wrote and say exactly what was expected when it does not pass.
The courses
Work through them in order, or jump to whichever one you need.