Polarimetric decomposition with python

i’m a beginner in python programming language, and i would like to use the polarimetric decomposition algorithms provided by esa rstb(toolbox) / S1tb in my python script.
i installed snap 8, python 3.4 and snappy, ( function available in GPF)
any available examples how to call these polarimetric functions (decomposition, speckles filtering… dual and full polarisation )
thanks in advance.