norvig/pytudes ? reverse-engineered prompt

Build me a small Python notebook collection for practicing tricky programming skills, like little coding studies rather than full tutorials.

I want a clean repo with an index README that lists each notebook, a short plain English description, and easy links to open in Colab or view in the browser. The notebooks should be grouped around things like Project Euler style problems, number puzzles, language and text puzzles, and a few more advanced topics like writing an interpreter or simple language model experiments.

Keep the code examples focused and readable, with each notebook teaching one idea well. Add any supporting data files or helper scripts only if they’re needed for the notebooks to run. Make sure the project feels polished and easy to browse, so someone can jump into any notebook and start learning by playing with the code. If you need to, look up current notebook link formats or Colab details online.