My system is giving me the attribute error, although I checked the paths from sys.path (It has all the required paths for the module and my module also contains the snapshot.py file). I had cloned the module from GitHub and alongside adding the new path in spyder, I had copied the whole module and pasted in my usually modules file as well.
I am not sure why it isn't able to locate the attribute. Kindly help.
I'm afraid I'm not sure - this is just going to be some python/path related problem, nothing specific to illustris_python. Just try starting your python session in the folder containing the illustris_python folder, and then try inside the illustris_python folder itself. If one of these works, just play with your PYTHONPATH until you can get it loaded.
Thank you for the prompt response! The problem seems to be resolved.