Hei. 

I want to find the location of a instance in an assembly. Is there any way I can obtain this information from the mdb?

I try to use getPosition(), but this function has no return values as getRotation() do.

>>> mdb.models[modelName].rootAssembly.instances[partName].getPosition()

The instance position relative to the Assembly CS is: 4, 0, 0
The instance was rotated by 89.999999 about the axis defined by the point 4, 0, 0 and the vector 0, 1, 0
The instance 'Part-2-1' has no position constraints.

>>> mdb.models[modelName].rootAssembly.instances['Part-2-1'].getRotation()
((4.0, 0.0, 0.0), (0.0, 1.0, 0.0), 89.999999)

Abaqus ​​​​​​​