convert.py

# input bitset array 
# output position of the bits that are 1

def parse_string_netfilter(s):
   lista = s.split(",")
   resp = []
   for i,x in enumerate(lista):
     b = "{:b}".format(int(x))[::-1]
     resp = resp + [int(j)+1+8*int(i) for j,y in enumerate(b) if y=="1"]
   return resp  

# Test
parse_string_netfilter("24,16,0,0,0,0")

# Should output [4, 5, 13]