Python: Bind to port 80 as root, then drop privileges?

I have written a small web server in Python, and now I would like to run it on port 80, but in order to be able to bind to a port below 1024 I need to have root privileges. I don't want to run the server as root, though. How can I bind to port 80 as root and then drop root privileges?

Thankful for help.