Pyhop works in both Python 2.7 and 3.2. It's fairly light-weight and can doesn't require many dependencies

Get started with Pyhop!

Pyhop integrates hierarchical task network planning with ordinary programming. HTN operators and methods - which refer to explicit states - are actually just ordinary Python functions

Begin planning HTNs

Pyhop maintains the same expressive power as classical planners, and is compatible with conventional programming techniques.

Read more on the Pyhop API