Django - The Web framework for perfectionists with deadlines
CherryPy - CherryPy allows developers to build web applications in much the same way they would build any other object-oriented Python program.
Flask - a microframework for Python based on Werkzeug, Jinja 2 and good intentions.
BlueBream - BlueBream is an open-source web application server, framework and library.
TurboGears - TurboGears is a web framework to create a database-driven, ready-to-extend application in minutes.
web2py - Web2py is an open source web application framework.