First I also wanted to add ast.Literal to literals: list, set, dict, etc. But it doesn't work, we loose the item order: set and dict are unordered. An optimizer must not change the order in which items are created. At least, not by default.

I'm talking about an hypothetical ast.Literal type which would take a Python object (list, set, etc.) Current ast.Set contains an ordered list of items, ast.Dict uses two ordered lists for keys and values.