You must have been using a different framework called "Django" than I did.
Have you used Django much? Some classes you run into frequently (besides Model):
* Form
* HttpResponse
* All middleware
* Template
* Etc, it's all classes except if you write function based views
Also this is Python, so you can poke the internals however you like :)
You can, but that doesn't mean you should. It's brittle. If your app or library breaks because a minor update to a dependency changed those internals completely, you can't say you weren't warned.