X = range(0,10)
target = np.array([0, 1] * 5)
print target

skf = model_selection.StratifiedKFold(n_splits = 2,shuffle = True)
for train_indices, test_indices in skf.split(X, target):
    print train_indices, test_indices
#[0 1 0 1 0 1 0 1 0 1]
#[1 2 4 9] [0 3 5 6 7 8]
#[0 3 5 6 7 8] [1 2 4 9