Your question requires the grouping of elements. Hence, an appropriate solution would be:
l = ['5','6','7', '8','9','10']
[(lambda x: tuple(int(e) for e in x))((i,j,k)) for (i, j, k) in zip(l[0::3], l[1::3], l[2::3])]
This outputs:
[(5, 6, 7), (8, 9, 10)]
As desired.