Not really.
Neither my wife nor myself have ever been bitten by a ball python and we've had hundreds over the years. We do have a couple that will hiss sometimes when you reach in thier tubs, but as soon as you take them out they mellow out. I did have a baby ball at a PetSmart strike at me, though. It was cute.
That said, we've both been bitten by just about every other species we've kept at one point or another.