Hi @shahza, I just want to confirm that you are referring to this SDK?
https://pypi.python.org/pypi/tobii-research
This is in fact only compatible with the Tobii Pro range of eye trackers, and is not compatible with the Tobii C4 or EyeX Tracker except without a special licence which is purchasable seperately.
Indeed, this forum is intended only for the Tobii Tech range of eye trackers and associated SDK, so it would be great if you could kindly confirm which hardware and software you are operating with. Thanks.