I've done a bit of research on what would be the best size tank/tub for an adult ball python. And I've heard two train of thoughts:

1) Adult BP's need at LEAST a 50 gallon tank.
2) Adult BP's fit comfortably in a 40 qt tub (which is about 10 gallons)

So, which is it? I figure the important part here is floor area? So the 40 qt tub actually has a lot of floor space but no height; and the 50 gallon has about the same floor area, but a lot of height.

Another question, is the best way to determine if the tank is the right size for a ball python is if it's body can run along the length and width of the container from nose to tail? I've heard that also and I don't know how accurate that is.

Thanks for any help!