a reticulated python is one of the most dangerous snakes and often extremly aggressive. So i´m sure he knows what he does.A reticulated python needs nowhere near the space as a arapaima.... You are in over you're head with not only it, but the rest of your fish. Look, I know its cool to have big things, but buying stuff before you can house it is wrong, and people are only going to look down on you for it. Same thing for making up stories. Nobody is going to think you're "cool" even if you had a silver/blue hybrid arowana. So stop trying to be a showoff.
Great Arapaima. I wish you much fun with that guy