reportArgumentType false trigger despite guard type narrowing code

[kiml]

When safety checking multiple values for None I've taken to using the following idiom in many cases (which I find quite neat) but pylance doesn't recognise it as a type narrowing guard.
The simplest test case would be:

if not None in [a_var, b_var, c_var]:
     func(a_var, ...) #  where a_var cannot be None etc

[rchiodo]

I don't believe that's a supported Type guard (for a python type checker). Supported type guards are described here:
https://typing.python.org/en/latest/guides/type_narrowing.html

[kiml]

Understood. So if I thought it worth pursuing I would have to raise a discussion around the PEP in that domain. Thanks. I guess you can close this then since it would seem unreasonable to expect pylance to deviate from the spec.

[rchiodo]

Yeah, proposing a new PEP would likely be the way to get that pattern supported.