What's the practice on a page?

A check question goes to your Maestro, which tells you whether you're on track and why. A worked example opens one step at a time: think through the next step first, then open it to compare.

Write what a short program will print and why, then run it and see what it printed beside your guess. Explain the difference in your own words. A guess is welcome: it's kept as you wrote it, to compare.

An open question with no right answer. What you write is saved to your account, and only you and your Maestro read it.

A Python exercise redraws its chart a moment after you stop typing, or at once with Run. An SQL exercise runs your query against fresh copies of the course's tables, so you can try anything. A workbench is a small project with files, an editor and a terminal: uv run, python and python -m run it, and ls, cd, pwd and cat look around. A boundary lab asks what a function does with each case before you run them all.

See where your code runs.

Some charts walk you through themselves step by step, and some have sliders to explore. Code you're meant to copy has a Copy button. An underlined word from the glossary opens its definition, with a way to ask your Maestro about it.