So I've done some reading about Python web frameworks (or servers?), mostly Tornado and Bottle but also FAPWS3, and there are still some grey areas.
First, these three web frameworks are all said to be fast, yet they all include a web server written in Python (except FAPWS3) which should be put behind nginx/Apache. Isn't this reducing the performance? I mean, we know that Python is much slower than C, why not only use nginx, or at worst, only the included Python web server?