It is common in machine learning to process data into the form (x,y),...,(x,y) but sometimes you may want two seperate lists: one for feature vectors and another for labels: [x,...,x], [y,...,y].

user647772 has a nice method:

>>> your_list = [(1,2), (3,4), (8,9)]
>>> [list(t) for t in zip(*your_list)]
[[1, 3, 8], [2, 4, 9]]