Making custom trait in S4 Studio

Hi! I'm new at modding for the sims 4 and really wanted to make some custom traits, but I have a mac so I cannot use the mod constructor (I tried opening with wine but it would not work). I am proficient with python, I just don't know where to start in the S4 Studio. Thanks 
Edit: slipped my mind when posting this but I would also like to make my traits compatible with wonderfulwhims impressions system if that's possible