This seems to produce the result you are after:
print 0xff ^ (sum( map hex,unpack '(a2)*','000181080002020202020202')
+& 0xff);;
103
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.