Added various python code.
Added various python code.

SheffieldML/GPmat,SheffieldML/GPmat,SheffieldML/GPmat,TianpeiLuke/GPmat,SheffieldML/forkedGPmat,TianpeiLuke/GPmat,TianpeiLuke/GPmat,SheffieldML/optimi,TianpeiLuke/GPmat,SheffieldML/forkedGPmat,SheffieldML/forkedGPmat,SheffieldML/forkedGPmat,TianpeiLuke/GPmat,SheffieldML/GPmat,SheffieldML/forkedGPmat,SheffieldML/GPmat,SheffieldML/forkedGPmat,SheffieldML/GPmat,TianpeiLuke/GPmat