Every online course on programming tells me to download a notebook and run it on Continuum.io (Jupyter). Why can't I watch a video and practice coding at the same time? I'd like to be able to have a notebook open so I can try coding while I watch a video lecture. Better yet, there are many meetup recordings out there on programming, data science, and big data. I wish I could rewatch them with a notebook open -- all in the same interface.