I don't think this is the right approach to you taking this interview. I don't think you should pretend knowing things you clearly do not know. If you do not use Unix on a daily basis why you want to give the impression that you know? If you do not know Python then do not pretend you know. I am not trying to put you down but I try to save you from a potentially very uncomfortable interview because interviewers/programmers/quant traders can smell from a mile away whether someone possesses coding skills and to what degree. Even if you get past those interviews by giving the impression away that you know something which you don't you will make your life incredibly stressful and hard should you be given the job offer, because things will be expected of you that you cannot perform.
I recommend to go into the interview and be yourself, just yourself. If it does not work out then it was most likely not a fit anyway. If you want to improve and strengthen your skills I recommend you do it on a daily basis rather than days before an interview, its just too obvious to figure out.