When comparing Tornado vs web.py, the Slant community recommends Tornado for most people. In the question“What are the best general-purpose Python web frameworks usable in production sites?” Tornado is ranked 7th while web.py is ranked 13th. The most important reason people chose Tornado is:
Tornado can scale to several open connections at the same time. This makes it perfect for applications where performance is very important.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Designed for performance
Tornado can scale to several open connections at the same time. This makes it perfect for applications where performance is very important.
Pro Amazing asynchronous functionalities
Pro Easy to set up and work with
Web.py is pretty easy to set up and start working with.
Cons
Con It's usually useful only when building real-time web applications
Because it's basically a framework for building real-time applications it has great support for things like WebScokets and uses non-blocking I/O. But it lacks in features that are used to build general-purpose websites like blogs, e-commerce sites, web portals etc...
For example it lacks ORM integration (at least out of the box) and it doesn't have a very powerful template engine.
Con Can feel constraining to work with
web.py does not have an ORM like Django, and it misses a lot of other features that it's competitors have. This can make developers feel too much constrained by this framework.