A = [ 1, 3, 5, 2, 4, 6, 7, 9,
11, 8, 10, 12, 13, 14, 15, 27,
11, 22, 33, 44, 55, 66, 77, 88]
group_length = 8
dict = {}
for i in range(int(len(A) / group_length)):
start = i * group_length
end = (i + 1) * group_length
key = A[start]
#
if key in dict:
continue
dict[key] = A[start + 1: end]
print(dict)
# {1: [3, 5, 2, 4, 6, 7, 9], 11: [8, 10, 12, 13, 14, 15, 27]}