Well said. I didn't see the comment about the hook, I don't use one, they don't work with such fast snakes. I do however use a hook with my Anaconda, as he is much slower generally, and a heavier bodied snake. But it may work with some people.
And I also agree, you really should look into what type of Ratsnake it is, as there is an awful lot of difference between the different species. I would imagine it would be one of the North American Rats, as these seem to be the ones that get rehomed a lot, but it could be anything. Not only do you need to find out because of environmental issues, but temperament wise, as I have already said, some generally do not calm down, others will calm with time, but you really need to find out as soon as possible so you can get a viv set up and running.