That patent is about a user interface for hiding/showing the code that creates particular rendered outputs, not for the general idea of a “notebook” UI.
I suspect there’s prior art (Hypercard? every spreadsheet ever? this list: https://en.wikipedia.org/wiki/List_of_graphical_user_interfa... ?), and the patent seems pretty obvious, but in any event, I don’t think other “code notebook” implementations are currently infringing this patent, and it seems relatively straightforward to work around.