Alexander Belopolsky wrote:
That's a question for Travis, but I would think that they would be immutable at the Python level, but mutable at the C level.
Well, anything's mutable at the C level -- the question is whether you *should* be mutating it.
I think the datatype object should almost certainly be immutable. Since it's separated from the data it's describing, it's possible for one datatype object to describe multiple chunks of data. So you wouldn't want to mutate one in case it's being used for something else that you don't know about.