No. Google App Engine does provide a free/cheap infrastructure for hosting Python applications, but Ruby has virtually the same thing with Heroku (and Heroku has a lot less restrictions that GAE). Before using GAE, make sure to read very closely about the restrictions that Google puts on the platform, many of which can be significant barriers to the goal you're trying to achieve. Carlos Ble's blog post goes into much more depth about the many restrictions he's run into, but I'll give you a quick overview:
- Python 2.7 only with no compiled extensions (major performance hit)
- 30 second request timeout (so much for easy large file uploads) and 10 second outside request timeout (so you can't query slow API's from your app)
- BigTable is stone age; no "LIKE" operators in your query and no single query can return more than 1,000 records
- Memcache has a 1 MB max value size
- Both BigTable and Memcache tend to die at a significant enough rate that it's productive to put code in your application to work around their failures
For a very small project, GAE is just fine; but if you're build something at a medium or large size, just be aware of the restrictions that may hamper you progress.
For more information about what sort of quotas and limitations you may have to deal with, see the GAE docs:
Also see this response on Stack Overflow: https://stackoverflow.com/a/3068371/189079