Matt Eland walks us through a sample:
This allows you to mix together rich documentation supported by little pieces of code that progressively expand upon an idea, tell a story, or otherwise provide insight or information to you as a developer.
Click through for the example. The thing I hadn’t realized—because I don’t really do this in Jupyter—is that you can share variables between languages. That’s a fairly useful feature when you want to do most of your work in one language but just happen to need a library using a different language.