I use PyCharm for development & debugging https://www.jetbrains.com/pycharm/. Tried Spyder long ago but find PyCharm works well for me (not sure where it falls on QT/wx divide).
But for Python teaching purposes, I’d really put in a strong recommendation for Rodeo https://www.yhat.com/products/rodeo
This isn’t as well-suited for full-on development (e.g. debugging). But it really shines as a data analysis environment. They’ve clearly been inspired by the RStudio IDE for R in terms of layout, but have produced something much cleaner and more minimalist. It has a pane for coding (and “Run” buttons) and a Python terminal. But like RStudio and Matlab, there is also a pane showing variables, which can be clicked on to inspect their contents. There are also panes for figures, documentation, the file system, command history, and so on.
So it is a very nice IDE for teaching Python programming for beginners, in the way it makes variables and their content more accessible and tangible (as it does for the file system). But for advanced users, it is an ideal environment for conducting data analysis. Worth trying out.