l = len(binnum)
s = binnum
dec = 0
for i in range(0,l):
    b = s[l-i-1]
    dec = dec + int(b)*(2**i)
return dec

if decnum==0:
    return "00000000"
bin=""
while decnum>0:
    bin = str(decnum%2) + bin
    decnum = decnum/2

if len(bin)%8 != 0:
    n = 8*(len(bin)/8 + 1) - len(bin)
    bin = "0" + bin
return bin