What is the correct expression to see a driver expression [driver.expression] for a material node with a driver originating from a datablock?
Newer Edit
Graph Window showing driver. Console inspection. Above.
Outliner window showing where the driver was added via the GUI. Above.
In the image above the UI shows that Sphere.008 has driver visible in the graph window and Python Console. I may have added the driver to this particular object or some other object which shares the same material. That action was not keenly audited. Why does a driver appear for a particular object when the material is being shared? This is really now a comprehension question about the [owner] of the driver.
Older Which has been addressed in the proposed answer below
Assume the following is valid Python and identifies what needs to be inspected
bpy.context.active_object.material_slots[0].material.node_tree.nodes["DataBlock"]
bpy.data.materials["Material400"].node_tree.nodes["DB400"]
Both lines above identify a valid object but fail to reach animation data.
Thanks.