title: Expandable List using Python Tkinter
body: <p>I know how to create a Listbox using Tkinter but this only allows me to display a list of single items. I need to create a expandable list that allows the user to hit something along the lines of a + next to the item which in turn opens up a new list with + buttons next to each item until you reach the leaf of a list. I was wondering if there was a way to implement this type of expandable list using Tkinter or if not if there was a different Python GUI tool that could do so?</p>