[jstimpfle]

> What would you expect to happen if the object is modified after being inserted into the dictionary?

This question is sometimes not important: When the mutable object is not mutated.

[luckystarr]

> This question is sometimes not important: When the mutable object is not mutated.

Which you can't guarantee when the object is mutable, so for consistency's sake it's left out.

Though you can always build your own Dict subclass and implement __hash__ on it and be angry with yourself when it fails. :)