Raster Calculator in Python

Hello,

I want to execute the following line in a python code:

SetNull(Raster2 < 2, Setnull(Raster2 != Raster1, Raster2))

Using the Raster Calculator, everything works fine. But I want to run it in a python routine.
Until now I got this:

from arcpy.sa import *
Raster_Final = SetNull (Raster2 < 2, SetNull (Raster2 != Raster1, Raster2))

This code doesn't return an error, but neither return what I want.
Could anybody help me?