[roenxi]

Language features either can, or cannot, be used.

Claiming that a language user should be prepared for certain parts of the language to disappear is a perfectly reasonable idea. But in practice it does not work. Because either it can or cannot be used, and if it can't be used it is a waste of time, if it can be used it must be supported.

Once people use a library, there will be pressure to support it forever and the mindshare switch is a real cost. A language bleeds users every time it drops a feature. The Python namespace is still polluted by documentation and tutorials talking about how to do things in v2 too.

[duckerude]

Rust seems to handle it ok. Features can spend a long time being nightly-only gated behind feature flags, while nevertheless seeing real world usage from people willing to brave the risk and churn.

But Python has a very different release schedule. Rust's nightly releases nightly and stable every six weeks, while Python only releases once a year. I don't think it could adopt the same model.

[coldtea]

>Claiming that a language user should be prepared for certain parts of the language to disappear is a perfectly reasonable idea. But in practice it does not work

Well, it can. That's what you get when there's no official package and you depend on third party packages that change all the time (e.g. common in the Node ecosystem, in GTK+ land, etc.), or are abandoned, etc.

Compared to that, a scheduled, anticipated process for candidate packages to include in the language (or remove eventually) is much easier.