Add __hash__ in Model

[azure]

Add __hash__ in Model

[johanste]

Should the hash take read-only/server generated values into account?

[lmazuel]

Currently Ansible is happy without (as you noticed, good catch :)). I have no strong opinion, I think __hash__ does not require unicity (contrary to __eq__, we can have hash(a) == hash(b) and a != b). So this is not a requirement for unicity at least. Is it the good thing? Right now I don't know.

[lmazuel]

@brettcannon Opinion on this one?

[brettcannon]

Are Models considered immutable? If they aren't then you should not be able to hash them. After that all the details of what you need to do for __hash__ is covered by the docs at https://docs.python.org/3/reference/datamodel.html#object.__hash__ (e.g. if a == b then hash(a) == hash(b)).

[lmazuel]

@brettcannon It was a note more than deep thought, sorry if I tagged you too ealier before even do some research... So, now I've read your link and the doc 😜

No they aren't immutable. But in most scenario, result from Azure are not changed, so this is interesting. Random ideas:

• How to raise an exception if we used hash on the obj, and try to change something inside after that? -
• Add a frozen method to send a frozen read-only model? @nitzmahone @johanste

[brettcannon]

You could also implement something like __getstate__ and return a tuple of immutable values (which you could then substantiate from and also gives you the ability to pickle the class if you want that functionality).