Currently the Python community is in the process of improving libraries to support the new iteration of the Python programming language. While the situation is greatly improving there are still some issues that make it hard for users to switch over to Python 3 just now.
We strongly recommend using Python 2.6 and 2.7 with activated Python 3 warnings during development.
Flask is a microframework for Python based on Werkzeug, Jinja 2 and good intentions. And before you ask: It's BSD licensed! (http://flask.pocoo.org/)
En plus, notamment:
$ mkvirtualenv my_great_app $ pip install flask $ pip install pygal $ pip freeze > requirements.txt
$ mkvirtualenv my_great_app $ pip install -r requirements.txt