Language feature-wise, I think python 3 has very little complained about it. The chief complaints about python I hear are anything to do with packaging software and multi threading the second of which will hopefully be fixed by 3.7.
Obviously, the 2 to 3 debacle is a constant source of grief, but I don't think that necessarily fits in with the subject at hand: language features that people contest over.
Obviously, the 2 to 3 debacle is a constant source of grief, but I don't think that necessarily fits in with the subject at hand: language features that people contest over.