📝 Add documentation for enums created via the functional API

[Torvaney]

This PR updates the documentation to include discussion of enumerating choices with enum.Enums created with the functional API. This is useful when creating choices dynamically, for example logging.

See further discussion of enums and the functional API in #389

[joaonc]

Looks great! Hope it gets merged soon.

[svlandeg]

Hi! Thanks for this contribution, and apologies for the delay in reviewing.

I agree that this additional section in the documentation could make it more clear for users on how to use "pure" Python Enum's with Typer.

I updated the PR with the latest from master and also included an Annotated version.

It's probably good if Tiangolo has another look at the exact phrasing in the documentation. I'll leave the final decision to merge or not with him.

[YuriiMotov]

mypy gives me

main.py:6: error: Second argument of Enum() must be string, tuple, list or dict literal for mypy to determine Enum members  [misc]

[svlandeg]

This particular error is a bit of a mypy quirck, if you have it as

NeuralNetwork = Enum("NeuralNetwork", {"simple": "simple", "conv": "conv", "lstm": "lstm"})

then it does pass the type check.

[YuriiMotov]

mypy gives:

main.py:10: error: Incompatible default for argument "network" (default has type "str", argument has type "NeuralNetwork")  [assignment]

[joaonc]

IIRC, this only works if the Enum extends str. You can either use StrEnum or have an something like class MyEnum(str, Enum)

[svlandeg]

Ah, that's unfortunate. We already have examples in the tutorial using Food(str, Enum), no need to repeat that here. And the current example does work, even if mypy complains. So I'm a bit on the fence what to do here. I guess our options are:

• merge as-is even if mypy complains (we don't test for it on the CI anyway, but good catch @YuriiMotov!)
• merge without the Annotated example
• don't merge and assume there are enough examples to use Enum and users will figure out what's best for them

[YuriiMotov]

I think it's better to "merge without the Annotated example".
Alternative would be to add # type: ignore[assignment] and explain that for now we have to ignore this error with Annotated approach

[github-actions]

📝 Docs preview

Last commit 556376a at: https://4436b468.typertiangolo.pages.dev

Modified Pages

• https://4436b468.typertiangolo.pages.dev/tutorial/parameter-types/enum/ - (before)