Re: [PATCH v5 19/36] qapi/events.py: add type hint annotations

[John Snow]

On 10/7/20 7:49 AM, Markus Armbruster wrote:
> Looks like commit message of PATCH 24 has an answer.
>
> Copy to all the commits that omit -> None similarly?

Probably not needed.

It's covered by the class basics section in the mypy manual; 
https://mypy.readthedocs.io/en/stable/class_basics.html#annotating-init-methods

and if you should happen to omit annotations for __init__ entirely as a 
novice, you will be treated to messages such as these:

qapi/source.py:18: error: Function is missing a return type annotation
qapi/source.py:18: note: Use "-> None" if function does not return a value
Found 1 error in 1 file (checked 14 source files)

Pretty good error!

There's no error if you DO explicitly add a -> None from __init__, but 
at worst it's just extraneous (but correct) information.

I could add a note to the style guide that I prefer omitting the return 
from __init__. I like omitting as much as I possibly can.

(You'll notice I don't always type every local, either -- when local 
inference is accurate, I leave it alone.)

--js