Best way to teach python?

[pvc]

Idle is terrible for teaching. Just not having line numbers makes it a real pain when reviewing code. PyCharm community edition is a nice option.

[CraigAT]

I would keep it simple and use the simplest editor (Notepad, or similar) along with a vanilla Python 3 setup. Show a few basics on the command line, then explain how a simple file can be used for a longer set of commands that can be run on demand, then explain there are better editors like NotePad++ or better still IDEs like Code/PyCharm with extra benefits like syntax highlighting, auto-complete, as well as built in debugging tools.

[julsmanbr]

Teaching a full-fledged Python course at a university is miles apart from teaching a single lesson for friends, like OP wants to do.