What is your favorite Python web framework?

I am doing some research for a Python framework to build web applications.
I have discarted Zope because from what I've read, the learning curve is
too steep, and it takes more time to build applications in general with
Zope.
I have kept the following:

  - PyWork - http://pywork.sourceforge.net (Not sure if it's mature)
  - Django - http://www.djangoproject.com (Looks interesting)
  - CherryPy - http://www.cherrypy.org (Unsure)

I have also found a more comprehensive list here:
http://wiki.python.org/moin/WebProgramming
But I'd like to know your opinion on what you think is best. The Python
framework I'll use will be to build an e-commerce application looking like
Amazon.com
I favor speed of development, intensive OO development, performance under
heavy load, short learning curve, good documentation and community.

-- 
Thanks,
Admin.
Want to buy me a book? http://tinyurl.com/78xzb :)