typing: Dynamically Create Literal Alias from List of Valid Values

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Go the other way around, and build VALID_ARGUMENTS from Argument:

Argument = typing.Literal['foo', 'bar']
VALID_ARGUMENTS: typing.Tuple[Argument, ...] = typing.get_args(Argument)

It’s possible at runtime to build Argument from VALID_ARGUMENTS, but doing so is incompatible with static analysis, which is the primary use case of type annotations. Building VALID_ARGUMENTS from Argument is the way to go.

I’ve used a tuple for VALID_ARGUMENTS here, but if for some reason you really prefer a list, you can get one:

VALID_ARGUMENTS: typing.List[Argument] = list(typing.get_args(Argument))

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