Remove suggestions to use deprecated type hints (List, Dict, Type, etc.)

[DFEvans]

Is your feature request related to a problem? Please describe.
As of Python 3.9, a large number of typing.Foo imports are deprecated: https://docs.python.org/3/library/typing.html#deprecated-aliases

The deprecations generally fall into two categories:

• Use foo[x] rather than typing.Foo[x]
• Use collections.abc.Foo rather than typing.Foo

Describe the solution you’d like
Hint text should refer to the new versions, at least in Python versions that support them. I can't find a clear statement of what Python versions are currently supported, but I suspect that no in-support Python 3 versions are incompatible with list[str].

For example, when I write the incorrect type(T), I should be told to use type[T], not Type[T]: https://github.com/microsoft/pyright/blob/d22c8004f225eeaa28bdb4a06d979eeb38171b12/packages/pyright-internal/src/localization/package.nls.en-us.json#L2078-L2081

[erictraut]

Pyright has a configuration option called deprecateTypingAliases that marks these symbols as deprecated. You can also combine this with reportDeprecated if you want to mark these as errors.

If you want the completion suggestions to avoid suggesting these deprecated symbols, that would require some additional logic in the language server code. The language server features for pyright are maintained by the Microsoft pylance team.

Could someone from the pylance team please transfer this enhancement request to the pylance-release project and triage/prioritize it as you see fit? Thanks!

[erictraut]

@rchiodo, @debonte

[rchiodo]

To be sure I understand, the request here is to eliminate this option from completions (and other similar types):

Seems unnecessary to me. You typed in the upper case version. We provided it to you.

It doesn't show up if you use lower case lis:

And the error is there in case you don't realize you shouldn't use the upper case version anymore.

[DFEvans]

Ah, sorry, I wasn't very clear - I'd forgotten to appreciate how wide a scope there would be for "you're giving the wrong type hint"!

What I mean are things like this suggestion below. I've written type(T) as a type hint, which is incorrect - I should use type[T]. However, the suggestion I'm given is to both:
a) Change () to [], which is the correct solution
b) Change type to Type, which is a poor suggestion as Type is deprecated
It's the b) part that I think is something to fix or improve on.

[erictraut]

Ah, I misinterpreted what you meant. You're referring to the wording of the error message.

The reason the error message suggests Type[T], List[T] and Dict[T] is because the lowercase versions do not work in Python 3.8 or older. Although the upper-case versions are deprecated, it's unlikely that they'll ever be removed (it would break too much existing code), so it's safe to use them.

In any case, Python 3.8 was recently EOL'ed (about a month ago), so I think it's reasonable to change the error message to refer to the lowercase version.

I've made that change in the pyright code base.