Note that in Vyper (John Skaller's Python variant) these are legit integer literals: 0b11111111 0B11111111 0o777 0O777 0d999 0D999 0xfFf 0XFFf Vyper's octal notation is still ugly, but whoever first thought 0777 != 777 was a "good idea" was certifiably insane <0.25 wink>.