Bone manipulations (with Python ?)

Hello,
I made an animation thanks to an armature, but some bones use constraints of location and rotation. I know it doesn’t work in BGE so I want to replace it by a Python script.
I use often Python, but I have never used Python with armatures yet and I don’t know how to do this (if it’s possible, of course).

If it’s not possible, I would like know so…