I've not used it in recent years, but PolarSSL (now mbed TLS) was quite nice for a crypto library. It's a light, simple and clear C library. Not directly code,

I've not used it in recent years, but PolarSSL (now mbed TLS) was quite nice for a crypto library. It's a light, simple and clear C library. Not directly code, but the "Beyond pep 8" talk at PyCon 2015 by Raymond Hettinger is quite nice (https://www.youtube.com/watch?v=wf-BqAjZb8M https://www.youtube.com/watch?v=wf-BqAjZb8M). It gives interesting tips on how to separate "business logic" (the high level problem you try to solve) from the "purely technical stuff".