OptiTrackPython
Improvements for the OptiTrack Python NatNetSDK
I tried the official SDK on Python 2, but it didn't work. Then I found this thread https://forums.naturalpoint.com/viewtopic.php?f=59&t=14929&p=64917&hilit=python+sdk#p64917 and decided to fix it myself ;)
Additionally, it had problems to work when the system had multiple network interfaces and I also fixed that :D
It still needs more tests...