There's loads of open data around that can be used to find out where trains and the tube are, and how they are running. But unless you know the systems and how they fit together, it can be a challenge to get started. This is a quick primer to the data, who provides it, where to find it and how to get started with it in Python. It's also great for beginners as it gives an introduction to simple data handling, and you can watch a train whiz past your window and then see it on your screen.