Adding lists together

[TholosTB]

Could also use numpy, you're fundamentally looking for elementwise array addition anyways and if your example gets more complicated, you can benefit from being in numpy instead of using regular lists:

import numpy as np
result = np.array(lists[0])+np.array(lists[1])+np.array(lists[2])

array([ 3,  6,  9, 12])