chore(typing): fix variance issues

Author: dangotbanned

narwhals/_compliant/dataframe.py

@@ -10,6 +10,7 @@
 
 from narwhals._compliant.typing import CompliantSeriesT_co
 from narwhals._compliant.typing import EagerSeriesT
+from narwhals._compliant.typing import EagerSeriesT_co
 
 if TYPE_CHECKING:
     from typing_extensions import Self
@@ -58,12 +59,12 @@ def schema(self) -> Mapping[str, DType]: ...
     def _iter_columns(self) -> Iterator[Any]: ...
 
 
-class EagerDataFrame(CompliantDataFrame[EagerSeriesT], Protocol[EagerSeriesT]):  # pyright: ignore[reportInvalidTypeVarUse]
+class EagerDataFrame(CompliantDataFrame[EagerSeriesT_co], Protocol[EagerSeriesT_co]):
     def _maybe_evaluate_expr(
-        self, expr: EagerExpr[EagerDataFrame[EagerSeriesT], EagerSeriesT] | T, /
-    ) -> EagerSeriesT | T:
+        self, expr: EagerExpr[EagerDataFrame[EagerSeriesT_co], EagerSeriesT_co] | T, /
+    ) -> EagerSeriesT_co | T:
         if is_eager_expr(expr):
-            result: Sequence[EagerSeriesT] = expr(self)
+            result: Sequence[EagerSeriesT_co] = expr(self)
             if len(result) > 1:
                 msg = (
                     "Multi-output expressions (e.g. `nw.all()` or `nw.col('a', 'b')`) "

narwhals/_compliant/series.py

@@ -30,11 +30,14 @@ def alias(self, name: str) -> Self: ...
 
 
 class EagerSeries(CompliantSeries, Protocol[NativeSeriesT_co]):
-    _native_series: NativeSeriesT_co
+    _native_series: Any
     _implementation: Implementation
     _backend_version: tuple[int, ...]
     _version: Version
 
+    @property
+    def native(self) -> NativeSeriesT_co: ...
+
     def _from_scalar(self, value: Any) -> Self:
         return self._from_iterable([value], name=self.name, context=self)
 

narwhals/_compliant/typing.py

@@ -40,3 +40,4 @@
 
 EagerDataFrameT = TypeVar("EagerDataFrameT", bound="EagerDataFrame[Any]")
 EagerSeriesT = TypeVar("EagerSeriesT", bound="EagerSeries[Any]")
+EagerSeriesT_co = TypeVar("EagerSeriesT_co", bound="EagerSeries[Any]", covariant=True)