Add option to prevent comment from being used as argument explanations

[yuanchen-zhu]

I find this library extremely useful. Thank you for your great work!

Is your feature request related to a problem? Please describe.
It would be nice to have an option to indicate only docstrings are used for argument explanations. I often have nonformal comments describing TODOs and intentions that should not be visible to the external user. Right now to stop it from showing up in the argument explanation, I need to explicitly add a docstring under it.

Describe the solution you'd like

Add an option in ArgumentParser that prevent comment from being used as argument explanation.

[lebrice]

Hey there @yuanchen-zhu ! Thanks for posting.

There are currently three potential sources for the "--help" string of a field, in order of priority:

class Foo:
     # The comment above the field (2nd priority)
     some_field: int = 123    # the comment next to the field (3rd priority)
     """ The docstring below the field (1st priority). """

Perhaps as a temporary workaround, you could put the help text in the docstring, and the todos above the field?

Let me know if that helps! :)

[yuanchen-zhu]

Appreciate the response Lebrice. Actually that's exactly what I'm currently doing (as mentioned in my post), so that I have to add a docstring underneath if I want to have comment. But if I forget to add a docstring, the comment gets exposed to the help text.

[lebrice]

Hey there @yuanchen-zhu , I'm sorry, you're right, I must have read your original post too quickly. There is currently no way to control this.
Let me think about this and I'll get back to you. Perhaps there could be a way to subclass the argument parser and override a method to do what you're looking for, I'll take a look.

[lebrice]

Here's a workaround for now: You can subclass this method in this way to completely customize what gets used to create the help text:

class CustomParser(simple_parsing.ArgumentParser):
    def _preprocessing(self, args: Sequence[str] = (), namespace: Namespace | None = None) -> None:
        for dc_wrapper in self._wrappers:
            for field_wrapper in dc_wrapper.fields:
                field_wrapper._docstring = dataclasses.replace(
                    field_wrapper._docstring,
                    comment_above="foo",
                    comment_inline="bar",
                    docstring_below="baz",
                    desc_from_cls_docstring="boo",
                )
        super()._preprocessing(args, namespace)

[yuanchen-zhu]

Thanks! Will try it out