Since Python 3 is the future, I directly started with Python 3 for my projects. While, There are some frameworks for Python 3, but I’m not a fan of frameworks. I prefer to glue the components myself and write the application – even if it involves more work and boilerplate code, and that’s because of freedom.
When you use a particular framework, you’re bound to a few rules and and modifying the behavior of the rules gets quite difficult, unless you know the framework you’re using from head to tail completely in detail. Half knowledge is very bad.