relational armature constraints and export with python

Hello, I just started working with blender and try to build a hand model for an interactive AR application.
I have two questions concerning constraint definition on armatures and export with python.

  1. I have limited and locked rotations on some joints. How can I read the locking state and the limits with Python. Neither the bone object nor the armature seems to have a constraint member.

  2. Is it possible to define constraints based on the state of different objects?
    I like to specify that the movement of two bones is related to each other. Say if bone 1 rotates alpha around x-axis, Bone 2 rotates 2/3 alpha around x-axis. How can I do this and how can I read the constraint in a python script.

Thanks for your help

  1. From:

limitmax and limitmin:


  1. Use Driven Keys:

That is using the movement of one object or bone to drive a Shape but you can use it to drive the movement of any other object.

You might also look at Action Constraint: