Here at Google, we use Python a great deal. The socket module from Python's standard library makes it possible to work with IPv4 addresses stored as integers or strings, but it doesn't allow you to easily work with subnets. And of course, since we support IPv6, we wanted to make working with v6 addresses as easy as v4.
We're happy to let you know that ipaddr.py, our internal library for IP addresses is now released as Open Source. It supports validation, subnet operations, and summarization, it works with both v4 and v6, and of course it has a comprehensive test suite. It's also one of the fastest libraries for common operations. We hope it will help you write your network tools, and ease your v6 transition.
Let us know what you think on our development mailing list. Enjoy!
Link - from Google Open Source Blog