If you're keen on using pure Python then you might enjoy using fabric. It's got fewer primitives than ansible, but allows you to write your logic easily.
It runs via SSH and requires no particularly special setup:
http://docs.fabfile.org/en/1.8/
If you're a perl lover then my own tool, Slaughter, allows you to install packages, fetch files, and make use of the large CPAN library:
http://www.steve.org.uk/Software/slaughter/guide/
Both of these tools are more basic than Ansible, but also more flexible, each in their own way.