Read Values in Cycles Material Nodes

Hi,

is there a way to evaluate Cycles material nodes with Python?

As a simple example l would like to read the result of a math node. So if the math node is set to “Add” and the first value is set to 0.5 and the second is set to 0.5 as well the Result should be 1.0.

I´ve tried with:

bpy.data.materials['MyCubeMat'].node_tree.nodes["Math.001"].outputs[0]

But the only answer I get is:

bpy.data...nodes["Math.001"].outputs[0]

What am I doing wrong?