def duplicates(lst, item):
       return [j for j, x in enumerate(lst) if x == item]
print(duplicates(XORcomb, 2)))

N = [1, 2, 3, 4, 5]

def duplicates(lst, item):
     return [i for i, x in enumerate(lst) if x == item]

for each in N:
     print("%r occurs at: %r " %(each, duplicates(XORcomb, each)))