In this solution, I installed and enabled mod_python.
Why doesn't adding this in .htaccess
AddHandler mod_python .py
PythonHandler mod_python.publisher
work?
It works if I add this in a <VirtualHost> configuration, but it doesn't seem to work from a .htaccess. This is a bit a shame, because some people don't have access to modify their <VirtualHost> configuration, and can only modify a .htaccess.
On the other hand, AddHandler php5-script .php seems to be available from .htaccess as detailed here.