In this example, we have only printed the result, but in a real project we could warn, abort the configuration, or set variables that could be queried to toggle certain configuration options.
It would be an interesting exercise to extend the code example to multiple Python modules, such as Cython, avoiding code repetition. One option could be to loop over the module names using foreach; another approach could be to abstract the code into a function or macro. We will discuss such abstractions in Chapter 7, Structuring Projects.
In Chapter 9, Mixed-language Projects, we will use Python CFFI and Cython, and the present recipe can serve as a useful and reusable code snippet to detect whether these packages are present.
