The are indeed 12870 combinations, as mentioned in the comments. However, we can indeed write them all for you ;).
from itertools import combinations
r = list(range(1,17))
all_combinations = [",".join(map(str, comb)) for comb in combinations(r, 8)]
with open('combinations.txt', 'a') as f:
f.write("\n".join(all_combinations))
produces
1,2,3,4,5,6,7,8
1,2,3,4,5,6,7,9
1,2,3,4,5,6,7,10
1,2,3,4,5,6,7,11
1,2,3,4,5,6,7,12
1,2,3,4,5,6,7,13
1,2,3,4,5,6,7,14
1,2,3,4,5,6,7,15
1,2,3,4,5,6,8,9
1,2,3,4,5,6,8,10
1,2,3,4,5,6,8,11
1,2,3,4,5,6,8,12
1,2,3,4,5,6,8,13
1,2,3,4,5,6,8,14
1,2,3,4,5,6,8,15
1,2,3,4,5,6,9,10
1,2,3,4,5,6,9,11
1,2,3,4,5,6,9,12
1,2,3,4,5,6,9,13
1,2,3,4,5,6,9,14
1,2,3,4,5,6,9,15
1,2,3,4,5,6,10,11
1,2,3,4,5,6,10,12
1,2,3,4,5,6,10,13
1,2,3,4,5,6,10,14
1,2,3,4,5,6,10,15
1,2,3,4,5,6,11,12
1,2,3,4,5,6,11,13
1,2,3,4,5,6,11,14
1,2,3,4,5,6,11,15
1,2,3,4,5,6,12,13
1,2,3,4,5,6,12,14
1,2,3,4,5,6,12,15
1,2,3,4,5,6,13,14
1,2,3,4,5,6,13,15
1,2,3,4,5,6,14,15
1,2,3,4,5,7,8,9
1,2,3,4,5,7,8,10
1,2,3,4,5,7,8,11
1,2,3,4,5,7,8,12
1,2,3,4,5,7,8,13
1,2,3,4,5,7,8,14
1,2,3,4,5,7,8,15
1,2,3,4,5,7,9,10
1,2,3,4,5,7,9,11
1,2,3,4,5,7,9,12
1,2,3,4,5,7,9,13
1,2,3,4,5,7,9,14
1,2,3,4,5,7,9,15
1,2,3,4,5,7,10,11
1,2,3,4,5,7,10,12
1,2,3,4,5,7,10,13
1,2,3,4,5,7,10,14
1,2,3,4,5,7,10,15
1,2,3,4,5,7,11,12
1,2,3,4,5,7,11,13
1,2,3,4,5,7,11,14
1,2,3,4,5,7,11,15
1,2,3,4,5,7,12,13
1,2,3,4,5,7,12,14
1,2,3,4,5,7,12,15
1,2,3,4,5,7,13,14
1,2,3,4,5,7,13,15
1,2,3,4,5,7,14,15
1,2,3,4,5,8,9,10
1,2,3,4,5,8,9,11
1,2,3,4,5,8,9,12
1,2,3,4,5,8,9,13
1,2,3,4,5,8,9,14
1,2,3,4,5,8,9,15
1,2,3,4,5,8,10,11
1,2,3,4,5,8,10,12
1,2,3,4,5,8,10,13
1,2,3,4,5,8,10,14
1,2,3,4,5,8,10,15
1,2,3,4,5,8,11,12
1,2,3,4,5,8,11,13
1,2,3,4,5,8,11,14
1,2,3,4,5,8,11,15
1,2,3,4,5,8,12,13
1,2,3,4,5,8,12,14
1,2,3,4,5,8,12,15
1,2,3,4,5,8,13,14
1,2,3,4,5,8,13,15
1,2,3,4,5,8,14,15
1,2,3,4,5,9,10,11
1,2,3,4,5,9,10,12
1,2,3,4,5,9,10,13
1,2,3,4,5,9,10,14
1,2,3,4,5,9,10,15
1,2,3,4,5,9,11,12
1,2,3,4,5,9,11,13
1,2,3,4,5,9,11,14
1,2,3,4,5,9,11,15
1,2,3,4,5,9,12,13
1,2,3,4,5,9,12,14
1,2,3,4,5,9,12,15
1,2,3,4,5,9,13,14
1,2,3,4,5,9,13,15
1,2,3,4,5,9,14,15
1,2,3,4,5,10,11,12
1,2,3,4,5,10,11,13
1,2,3,4,5,10,11,14
1,2,3,4,5,10,11,15
1,2,3,4,5,10,12,13
1,2,3,4,5,10,12,14
1,2,3,4,5,10,12,15
1,2,3,4,5,10,13,14
1,2,3,4,5,10,13,15
1,2,3,4,5,10,14,15
1,2,3,4,5,11,12,13
1,2,3,4,5,11,12,14
1,2,3,4,5,11,12,15
1,2,3,4,5,11,13,14
1,2,3,4,5,11,13,15
1,2,3,4,5,11,14,15
1,2,3,4,5,12,13,14
1,2,3,4,5,12,13,15
1,2,3,4,5,12,14,15
1,2,3,4,5,13,14,15
1,2,3,4,6,7,8,9
1,2,3,4,6,7,8,10
1,2,3,4,6,7,8,11
1,2,3,4,6,7,8,12
1,2,3,4,6,7,8,13
1,2,3,4,6,7,8,14
1,2,3,4,6,7,8,15
1,2,3,4,6,7,9,10
1,2,3,4,6,7,9,11
1,2,3,4,6,7,9,12
1,2,3,4,6,7,9,13
1,2,3,4,6,7,9,14
1,2,3,4,6,7,9,15
1,2,3,4,6,7,10,11
1,2,3,4,6,7,10,12
1,2,3,4,6,7,10,13
1,2,3,4,6,7,10,14
1,2,3,4,6,7,10,15
1,2,3,4,6,7,11,12
1,2,3,4,6,7,11,13
1,2,3,4,6,7,11,14
1,2,3,4,6,7,11,15
1,2,3,4,6,7,12,13
1,2,3,4,6,7,12,14
1,2,3,4,6,7,12,15
1,2,3,4,6,7,13,14
1,2,3,4,6,7,13,15
1,2,3,4,6,7,14,15
1,2,3,4,6,8,9,10
1,2,3,4,6,8,9,11
1,2,3,4,6,8,9,12
1,2,3,4,6,8,9,13
1,2,3,4,6,8,9,14
1,2,3,4,6,8,9,15
1,2,3,4,6,8,10,11
1,2,3,4,6,8,10,12
1,2,3,4,6,8,10,13
1,2,3,4,6,8,10,14
1,2,3,4,6,8,10,15
1,2,3,4,6,8,11,12
1,2,3,4,6,8,11,13
1,2,3,4,6,8,11,14
1,2,3,4,6,8,11,15
1,2,3,4,6,8,12,13
1,2,3,4,6,8,12,14
1,2,3,4,6,8,12,15
1,2,3,4,6,8,13,14
1,2,3,4,6,8,13,15
1,2,3,4,6,8,14,15
1,2,3,4,6,9,10,11
1,2,3,4,6,9,10,12
1,2,3,4,6,9,10,13
1,2,3,4,6,9,10,14
1,2,3,4,6,9,10,15
1,2,3,4,6,9,11,12
1,2,3,4,6,9,11,13
1,2,3,4,6,9,11,14
1,2,3,4,6,9,11,15
1,2,3,4,6,9,12,13
1,2,3,4,6,9,12,14
1,2,3,4,6,9,12,15
1,2,3,4,6,9,13,14
1,2,3,4,6,9,13,15
1,2,3,4,6,9,14,15
1,2,3,4,6,10,11,12
1,2,3,4,6,10,11,13
1,2,3,4,6,10,11,14
1,2,3,4,6,10,11,15
1,2,3,4,6,10,12,13
1,2,3,4,6,10,12,14
1,2,3,4,6,10,12,15
1,2,3,4,6,10,13,14
1,2,3,4,6,10,13,15
1,2,3,4,6,10,14,15
1,2,3,4,6,11,12,13
1,2,3,4,6,11,12,14
1,2,3,4,6,11,12,15
1,2,3,4,6,11,13,14
1,2,3,4,6,11,13,15
1,2,3,4,6,11,14,15
1,2,3,4,6,12,13,14
1,2,3,4,6,12,13,15
1,2,3,4,6,12,14,15
1,2,3,4,6,13,14,15
1,2,3,4,7,8,9,10
1,2,3,4,7,8,9,11
1,2,3,4,7,8,9,12
1,2,3,4,7,8,9,13
1,2,3,4,7,8,9,14
1,2,3,4,7,8,9,15
1,2,3,4,7,8,10,11
1,2,3,4,7,8,10,12
1,2,3,4,7,8,10,13
1,2,3,4,7,8,10,14
1,2,3,4,7,8,10,15
1,2,3,4,7,8,11,12
1,2,3,4,7,8,11,13
1,2,3,4,7,8,11,14
1,2,3,4,7,8,11,15
1,2,3,4,7,8,12,13
1,2,3,4,7,8,12,14
1,2,3,4,7,8,12,15
1,2,3,4,7,8,13,14
1,2,3,4,7,8,13,15
1,2,3,4,7,8,14,15
1,2,3,4,7,9,10,11
1,2,3,4,7,9,10,12
1,2,3,4,7,9,10,13
1,2,3,4,7,9,10,14
1,2,3,4,7,9,10,15
1,2,3,4,7,9,11,12
1,2,3,4,7,9,11,13
1,2,3,4,7,9,11,14
1,2,3,4,7,9,11,15
1,2,3,4,7,9,12,13
1,2,3,4,7,9,12,14
1,2,3,4,7,9,12,15
1,2,3,4,7,9,13,14
1,2,3,4,7,9,13,15
1,2,3,4,7,9,14,15
1,2,3,4,7,10,11,12
1,2,3,4,7,10,11,13
1,2,3,4,7,10,11,14
1,2,3,4,7,10,11,15
1,2,3,4,7,10,12,13
1,2,3,4,7,10,12,14
1,2,3,4,7,10,12,15
1,2,3,4,7,10,13,14
1,2,3,4,7,10,13,15
1,2,3,4,7,10,14,15
1,2,3,4,7,11,12,13
1,2,3,4,7,11,12,14
1,2,3,4,7,11,12,15
1,2,3,4,7,11,13,14
1,2,3,4,7,11,13,15
1,2,3,4,7,11,14,15
1,2,3,4,7,12,13,14
1,2,3,4,7,12,13,15
1,2,3,4,7,12,14,15
1,2,3,4,7,13,14,15
1,2,3,4,8,9,10,11
1,2,3,4,8,9,10,12
1,2,3,4,8,9,10,13
1,2,3,4,8,9,10,14
1,2,3,4,8,9,10,15
1,2,3,4,8,9,11,12
1,2,3,4,8,9,11,13
1,2,3,4,8,9,11,14
1,2,3,4,8,9,11,15
1,2,3,4,8,9,12,13
1,2,3,4,8,9,12,14
1,2,3,4,8,9,12,15
1,2,3,4,8,9,13,14
1,2,3,4,8,9,13,15
1,2,3,4,8,9,14,15
1,2,3,4,8,10,11,12
1,2,3,4,8,10,11,13
1,2,3,4,8,10,11,14
1,2,3,4,8,10,11,15
1,2,3,4,8,10,12,13
1,2,3,4,8,10,12,14
1,2,3,4,8,10,12,15
1,2,3,4,8,10,13,14
1,2,3,4,8,10,13,15
1,2,3,4,8,10,14,15
1,2,3,4,8,11,12,13
1,2,3,4,8,11,12,14
1,2,3,4,8,11,12,15
1,2,3,4,8,11,13,14
1,2,3,4,8,11,13,15
1,2,3,4,8,11,14,15
1,2,3,4,8,12,13,14
1,2,3,4,8,12,13,15
1,2,3,4,8,12,14,15
1,2,3,4,8,13,14,15
1,2,3,4,9,10,11,12
1,2,3,4,9,10,11,13
1,2,3,4,9,10,11,14
1,2,3,4,9,10,11,15
1,2,3,4,9,10,12,13
1,2,3,4,9,10,12,14
1,2,3,4,9,10,12,15
1,2,3,4,9,10,13,14
1,2,3,4,9,10,13,15
1,2,3,4,9,10,14,15
1,2,3,4,9,11,12,13
1,2,3,4,9,11,12,14
1,2,3,4,9,11,12,15
1,2,3,4,9,11,13,14
1,2,3,4,9,11,13,15
1,2,3,4,9,11,14,15
1,2,3,4,9,12,13,14
1,2,3,4,9,12,13,15
1,2,3,4,9,12,14,15
1,2,3,4,9,13,14,15
1,2,3,4,10,11,12,13
1,2,3,4,10,11,12,14
1,2,3,4,10,11,12,15
1,2,3,4,10,11,13,14
1,2,3,4,10,11,13,15
1,2,3,4,10,11,14,15
1,2,3,4,10,12,13,14
1,2,3,4,10,12,13,15
1,2,3,4,10,12,14,15
1,2,3,4,10,13,14,15
1,2,3,4,11,12,13,14
1,2,3,4,11,12,13,15
1,2,3,4,11,12,14,15
1,2,3,4,11,13,14,15
1,2,3,4,12,13,14,15
1,2,3,5,6,7,8,9
1,2,3,5,6,7,8,10
1,2,3,5,6,7,8,11
1,2,3,5,6,7,8,12
1,2,3,5,6,7,8,13
1,2,3,5,6,7,8,14
1,2,3,5,6,7,8,15
1,2,3,5,6,7,9,10
1,2,3,5,6,7,9,11
1,2,3,5,6,7,9,12
1,2,3,5,6,7,9,13
1,2,3,5,6,7,9,14
1,2,3,5,6,7,9,15
1,2,3,5,6,7,10,11
1,2,3,5,6,7,10,12
1,2,3,5,6,7,10,13
1,2,3,5,6,7,10,14
1,2,3,5,6,7,10,15
1,2,3,5,6,7,11,12
1,2,3,5,6,7,11,13
1,2,3,5,6,7,11,14
1,2,3,5,6,7,11,15
1,2,3,5,6,7,12,13
1,2,3,5,6,7,12,14
1,2,3,5,6,7,12,15
1,2,3,5,6,7,13,14
1,2,3,5,6,7,13,15
1,2,3,5,6,7,14,15
1,2,3,5,6,8,9,10
1,2,3,5,6,8,9,11
1,2,3,5,6,8,9,12
1,2,3,5,6,8,9,13
1,2,3,5,6,8,9,14
1,2,3,5,6,8,9,15
1,2,3,5,6,8,10,11
1,2,3,5,6,8,10,12
1,2,3,5,6,8,10,13
1,2,3,5,6,8,10,14
1,2,3,5,6,8,10,15
1,2,3,5,6,8,11,12
1,2,3,5,6,8,11,13
1,2,3,5,6,8,11,14
1,2,3,5,6,8,11,15
1,2,3,5,6,8,12,13
1,2,3,5,6,8,12,14
1,2,3,5,6,8,12,15
1,2,3,5,6,8,13,14
1,2,3,5,6,8,13,15
1,2,3,5,6,8,14,15
1,2,3,5,6,9,10,11
1,2,3,5,6,9,10,12
1,2,3,5,6,9,10,13
1,2,3,5,6,9,10,14
1,2,3,5,6,9,10,15
1,2,3,5,6,9,11,12
1,2,3,5,6,9,11,13
...
run the code yourself to get the rest.