Finals and Literals: Spec contradiction

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首先，将 typing specification 中关于 Final 语法和字面量使用的措辞与 PEP 591 和 PEP 586 进行比较。检查 conformance/tests/qualifiers_final_annotation.py，尤其是第 11-13 行，并在需要时扩展相关用例。当 specification 内部一致且 conformance tests 反映澄清后的行为时，即视为完成。

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描述

topic: conformance tests topic: typing spec

This came up in python/typeshed#16301. I assume this is mostly a clerical/historical error, but let me know if we should follow the whole spec change process.

The typing spec says about Final:

Example:

ID: Final = 1

The typechecker should apply its usual type inference mechanisms to determine the type of ID (here, likely, int).

And then a bit later:

Type checkers should treat uses of a final name that was initialized with a literal as if it was replaced by the literal.

Both sentences are copied directly from PEP 591, which overlapped with the Literals PEP 586.

I assume that we should change the first sentence to "here, likely, Literal[1]" and change the second sentence to be a bit more concrete along these lines:

Type checkers should infer uses of a final name that was initialized with a literal X as Literal[X] if X is an allowed literal type (cf. to the literals section). Otherwise, they should infer the type of the X.

(And maybe extend the example after a bit.)

In fact, this is what the conformance tests already check:

https://github.com/python/typing/blob/cf943ccbea5596ef969eec6e2260097ff697b7ba/conformance/tests/qualifiers_final_annotation.py#L11-L13

(Although the tests could be extended a bit.)

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