use np.r_
np.r_[1:10, 15, 17, 50:100]
array([ 1, 2, 3, 4, 5, 6, 7, 8, 9, 15, 17, 50, 51, 52, 53, 54, 55,
56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72,
73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89,
90, 91, 92, 93, 94, 95, 96, 97, 98, 99])
so you can do
df.iloc[:, np.r_[1:10, 15, 17, 50:100]]