Integrating code written using different technologies does not end with C/C++. A lot of libraries, especially third-party software with closed sources, are distributed as compiled binaries. In C, it is really easy to load such shared/dynamic libraries and call their functions. This means that you can use any C library as long as you wrap it with extensions using Python/C API.
This, of course, is not the only solution and there are tools such as ctypes or CFFI that allow you to interact with dynamic libraries using pure Python without the need for writing extensions in C. Very often, the Python/C API may still be a better choice because it provides a better separation between the integration layer (written in C) and the rest of your application.
The next section shows us how to create custom datatypes.