Is there a script controller for controlling position and rotation of pose bones?

Hi.

I’ve been testing Blender once again for a while. I haven’t had much time, so I will ask this.

I’ve looked into constraints and drivers, but at first glance there doesn’t seem to be a controller / constraint that would just have ability to add variables and python code to drive object and pose bone transforms? Similar to what 3ds Max has.

I know drivers can be used to drive at least one channel, but it is a hassle and the UI is convoluted for such a simple purpose. It would be way more easier to just create a single custom script to control (for example) center spine segment rotation and position based on its end point positions.

I’d like to control PRS transform of a bone with one script… after all Blender uses Python nearly everywhere so it feels like this feature has to be somewhere…

Have I missed somehow this feature?

Thanks in advance!