If compared to cobra on venom ranking which one will be dangerous?

If your looking at venom the cobra is more dangerous as the boa and pythons do not use venom as they are constrictors. Between the 2 constrictors i would say normally a boa would be more dangerous then a python as it gets bigger. That is unless your talking about a Burmese python which is the worlds longest snake (most think anacondas are but they are just the fattest).

Source: Own 3 ball pythons and 2 burmese