Why would you want to have a Python C++-extension in the first place?
The answer is quite simple: Performance.
Although you can achieve improved performance using Cython, you can never beat C/C++ level performance.

This template provides a very basic Python extension written in C/C++.
The extension module "template" contains a function "test" and a class "example_class".
The "example_class" has a single member "value" (of type double => float), and supports a lot of operations.
It also shows how to import a module ("math.pi" in this case).

Work in progress.