One or more?

[pawamoy]

I can't seem to find whether it's possible to require one or more arguments to be consumed. There's only num_args=-1 for zero or more. I tried using num_args=-1, required=True but this didn't change anything.

[DanCardin]

There's always

class Foo:
    foo_required: An[int, Arg(value_name='foo')]
    foo_rest: An[list[int], Arg(value_name='foo')]

    @property
    def foo(self):
        return [self.foo_required, *self.foo_rest]

I was going to suggest this (but it doesn't work correctly atm, for a reason).

class Foo:
    foo: An[list[int], Arg(num_args=1, group=Group()), Arg(group=Group())]

And there's also parse as an option for disallowing empty lists manually.

---

As far as a "native" feature, with required...i'll have to attempt to make that modification to the parser and see what breaks, if anything.

[pawamoy]

That seems right indeed 🤔 So it means that, once the inferred required is correctly used:

• a list[str] arg with no default will require one or more args
• to make it optional again, we'll have to pass required=False
• in both cases we don't need to pass num_args=-1 anymore (not sure I got this one right)

Sounds much cleaner 😄

[DanCardin]

to make it optional, you'd have to provide a default, which would then infer required=False. there's a preexisting validation that validates you have a default if you explicitly specify required=False.

This is (iirc) because not all types have an obvious default cappa cna choose, and if you're explicitly saying it's not required, that implies someone needs to choose a default.

but yes, no need to specify num_args.

foo: list[str] == Arg(num_args=-1, required=True)
foo: list[str] = field(default_factory=list) == Arg(num_args=-1, required=False, default=Default(ValueFrom(list)))
foo: Anntoated[list[str], Arg(required=False)] == raise ValueError`

[pawamoy]

OK, perfect, thanks!

[DanCardin]

#187