How can you learn how to use a library and help others at the same time? Write a tutorial!

We will start with the planning of the tutorial (the help of a mentor can be useful, and tips to find one are given). We will then follow the GTK+3 tutorial for beginners (Python version) to see how such a tutorial comes to life - and what you can learn from it. From creating a window we will move to adding an image to it, then to dealing with buttons (therefore signals and callbacks); more and more complex examples will follow, from scales to dialogs to the widgets using the model/view/controller design (combobox and treeview). Finally, we will discuss the pitfalls to avoid after your job is done.