feat: Adds nw.exclude

[thomasjpfan]

What type of PR is this? (check all applicable)

• 💾 Refactor
• ✨ Feature
• 🐛 Bug Fix
• 🔧 Optimization
• 📝 Documentation
• ✅ Test
• 🐳 Other

Related issues

• Closes nw.exclude #2083

Checklist

• Code follows style guide (ruff)
• Tests added
• Documented the changes

If you have comments or can explain your changes, please do so below

This PR adds nw.exclude and unit tests.

[FBruzzesi]

Thanks for the contribution @thomasjpfan 🚀

I left a few comments - those in the _arrow module apply to all other modules. In general we might try lower some repetition: evaluate_output_names is always the same function for all backends and the selection is quite close to ComlpliantExpr.from_column_names. Maybe we could generalize that a bit to be re-usable

[FBruzzesi]

I wonder if we could tweak ArrowExpr.from_column_names and use it here 🤔 It might be a refactor follow up

[thomasjpfan]

The refactor would be to accept able callable that returns the names.

@classmethod
def from_column_names(
    cls,
    get_column_names,  # callable
    function_name,
    backend_version,
    version,
):
    def func(df):
        return [... for column_name in get_column_names(df)]

    return cls(
        func,
        function_name=function_name,
        evaluate_output_names=get_column_names
    )

Then exclude and col gets refactored to:

def col(self: Self, *column_names: str):
    return ArrowExpr.from_column_names(
        lambda _: column_names, function_name="col", ...
    )

def exclude(self: Self, *column_names: str):
    def get_column_names(df) -> Sequence[str]:
        exclude_names = set(column_names)
        return [
            column_name
            for column_name in df.columns
            if column_name not in exclude_names
        ]

     return ArrowExpr.from_column_names(
         get_column_names,
         function_name="exclude", ...
     )

---

I did not want to increase the scope of this PR by changing the signature of from_column_names and changing col. I'm okay with doing a quick follow up.

[FBruzzesi]

Thanks @thomasjpfan

The refactor would be to accept able callable that returns the names.

Yes I think in the long term that's desirable and we should aim for that

I did not want to increase the scope of this PR by changing the signature of from_column_names and changing col. I'm okay with doing a quick follow up.

Happy to keep it as follow up

[FBruzzesi]

Thanks @thomasjpfan 🚀

[FBruzzesi]

Thanks @thomasjpfan

The refactor would be to accept able callable that returns the names.

Yes I think in the long term that's desirable and we should aim for that

I did not want to increase the scope of this PR by changing the signature of from_column_names and changing col. I'm okay with doing a quick follow up.

Happy to keep it as follow up

[dangotbanned]

Thanks everyone (especially @thomasjpfan) 🎉