📝 Fix outdated optional *CLI argument* section in tutorial

[gkeuccsr]

To match the example, description is updated

[github-actions]

📝 Docs preview for commit 729182b at: https://1d0969a6.typertiangolo.pages.dev

Modified Pages

• https://1d0969a6.typertiangolo.pages.dev/tutorial/arguments/optional/

[svlandeg]

Thanks for the PR! The text has indeed gotten a bit out of date as the example code now uses Annotated.

I've rewritten the text again, because we shouldn't focus on the Optional part of the type annotation, as that is not what is making the CLI argument optional 🙃 We need to focus the reader on the fact that there is a default value; whether that is None or not and whether or not the type is Optional[X] is irrelevant. We could also have had

name: Annotated[str, typer.Argument()] = "Rick"

for example. This is sufficiently explained in various parts of the documentation so doesn't need repeating here, but we just need to make sure to avoid confusion with the rephrasing.

Anyway - thanks again for spotting this!

[svlandeg]

I've now rewritten it so that it covers both Annotated and non-Annotated code snippets:

name: Optional[str] = typer.Argument(default=None)

&

name: Annotated[Optional[str], typer.Argument()] = None

[gkeuccsr]

From the point of someone, who were reading the tutorial for the first time (me), that's still confusing if you go from the previous examples:

name: Annotated[str, typer.Argument()]

...that works exactly the same as

name: str

where you only see typer.Argument() used inside the type definition. And peeking in the next example from the phrase in subject, you see only:

Now we have:

name: Annotated[Optional[str], typer.Argument()] = None

So I'd suggest adding both variants you mentioned in tutorial, like:

name: Annotated[Optional[str], typer.Argument()] = None

...that works exactly the same as

name: Optional[str] = typer.Argument(default=None)

And placing the Annotated version first as it is recommended in the rest of the tutorial.

[svlandeg]

Hm, I see.

I wonder whether it would be less confusing if the first example of an optional argument doesn't actually use None as default, but some other random value. I think that would help enforce the idea that the default is all that matters, and that Optional is only used to support None as a potential value. What do you think?

[github-actions]

📝 Docs preview for commit 014882c at: https://a3d15f63.typertiangolo.pages.dev

Modified Pages

• https://a3d15f63.typertiangolo.pages.dev/tutorial/arguments/optional/