Re: PEP 505 (None-aware operators) for Python 3.11

Hi all,

I've only here found out that there is a discussion going on about those 
none-aware operators and my first thought was "great, finally!". FWIW, 
I'd be happy with the syntax suggestion in the PEP, since '?' looks 
rather intuitive to me to mean something like "maybe".

However, I then read the mentioned post of Steve Dower, with the final 
summary:

 > So to summarise my core concern - allowing an API designer to "just 
use None" is a cop out, and it lets people write lazy/bad APIs rather 
than coming up with good ones.

This is a very good point. In fact, I've never really thought about it 
that way and of course he's totally right that "SomeType | None" (or 
Optional[SomeType], which also somehow made me feel that this usage is 
fairly intended) is not optimal, at least for user defined 
types/classes. The problem is, that I never actually thought about his 
suggested way. And I wouldn't be surprised if this holds for many other 
people as well.

Maybe it would be great to boldly mention these thoughts in the 
documentation at an appropriate place. In my opinion, there are at least 
the following good places where this would fit nicely:

- The documentation of the dataclasses 
(https://docs.python.org/3/library/dataclasses.html), since this is 
probably the most common use case for the "| None" pattern. Going 
further, the dataclasses functionality might even be extended to make it 
simpler to generate such null-types (or however they are called), so 
that it is no longer "a tonne more work".

- Linters like pylint could emit a note when seeing the "| None" 
pattern, linking to the explanation about why it is possibly not the 
best way to do it.

- The documentation of the discussed None-aware operators. Since these 
new operators are closely coupled to the arguably suboptimal "| None" 
pattern, it is probably good to tell folks right there why they should 
consider better alternatives.

As mentioned, I absolutely see Steve's point. However, there are many 
Python scripts/programs working without a complex API, where this "| 
None" pattern may still have its legitimate uses and the none-aware 
operators can make code easier to read (and write).

Best regards,
Philipp