chore(typing): Fill out CompliantNamespace protocol

[dangotbanned]

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

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

Related issues

• refactor: Add CompliantSeries.from_numpy #2196
• feat: Spec'd-out CompliantExpr #2119
• Commitment to keep package size down #1942

Checklist

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

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

• _create_compliant_series is removed in refactor: Add CompliantSeries.from_numpy #2196
• Turned out to be much easier than CompliantExpr
• See thread to understand the LOC drop

[dangotbanned]

• Return type would require another generic protocol for When
• Doing that is a pretty low priority for now

[dangotbanned]

Oooh we might be able to implement this (and maybe a few other methods) higher up in the protocol 🤯

• refactor: allow callable in CompliantExpr.from_column_names to reuse for CompliantNamespace.<all|col|exclude> #2134

[dangotbanned]

from narwhals.utils import get_column_names

class CompliantNamespace(Protocol[CompliantFrameT, CompliantExprT]):
    @property
    def _expr(self) -> type[CompliantExprT]: ...

    def all(self) -> CompliantExprT:
        return self._expr.from_column_names(
            get_column_names,
            function_name="all",
            implementation=self._implementation,
            backend_version=self._backend_version,
            version=self._version,
        )

[dangotbanned]

Already most of the way there in

narwhals/narwhals/_pandas_like/namespace.py

Lines 77 to 96 in d860054

	# --- selection ---
	def col(self: Self, *column_names: str) -> PandasLikeExpr:
	return self._expr.from_column_names(
	passthrough_column_names(column_names), function_name="col", context=self
	)
	def exclude(self: Self, excluded_names: Container[str]) -> PandasLikeExpr:
	return self._expr.from_column_names(
	partial(exclude_column_names, names=excluded_names),
	function_name="exclude",
	context=self,
	)
	def nth(self: Self, *column_indices: int) -> PandasLikeExpr:
	return self._expr.from_column_indices(*column_indices, context=self)
	def all(self: Self) -> PandasLikeExpr:
	return self._expr.from_column_names(
	get_column_names, function_name="all", context=self
	)

[dangotbanned]

@FBruzzesi ignore this if you're not fully back yet 🙂

Thought you might like to see this new possibility - following the recent spec-ing of the Compliant* protocols

[dangotbanned]

Went ahead with that in (5d609a7)

We now have default implementations for 4x CompliantNamespace methods 😁

[dangotbanned]

This only got flagged after filling out the protocol.

[MarcoGorelli]

thanks @dangotbanned !