Most hosting companies support PHP web applications but few support Python web applications.

Google just launched Google App Engine – a hosted environment that uses Python and YAML and it even offers a no-risk free start-up pack.

During this preview period, applications are limited to 500MB of storage, 200M megacycles of CPU per day, and 10GB bandwidth per day. We expect most applications will be able to serve around 5 million pageviews per month. In the future, these limited quotas will remain free, and developers will be able to purchase additional resources as needed.

Yahoo !!

Google App Engine Blog: Introducing Google App Engine + our new blog