refactor(DRAFT): start migrating PandasLike*

Author: dangotbanned

narwhals/_pandas_like/dataframe.py

@@ -10,6 +10,7 @@
 
 import numpy as np
 
+from narwhals._compliant import EagerDataFrame
 from narwhals._expression_parsing import evaluate_into_exprs
 from narwhals._pandas_like.series import PANDAS_TO_NUMPY_DTYPE_MISSING
 from narwhals._pandas_like.series import PandasLikeSeries
@@ -26,6 +27,8 @@
 from narwhals._pandas_like.utils import select_columns_by_name
 from narwhals.dependencies import is_numpy_array_1d
 from narwhals.exceptions import InvalidOperationError
+from narwhals.typing import CompliantDataFrame
+from narwhals.typing import CompliantLazyFrame
 from narwhals.utils import Implementation
 from narwhals.utils import check_column_exists
 from narwhals.utils import generate_temporary_column_name
@@ -54,8 +57,6 @@
     from narwhals.typing import _2DArray
     from narwhals.utils import Version
 
-from narwhals.typing import CompliantDataFrame
-from narwhals.typing import CompliantLazyFrame
 
 CLASSICAL_NUMPY_DTYPES: frozenset[np.dtype[Any]] = frozenset(
     [
@@ -83,7 +84,7 @@
 )
 
 
-class PandasLikeDataFrame(CompliantDataFrame["PandasLikeSeries"], CompliantLazyFrame):
+class PandasLikeDataFrame(EagerDataFrame["PandasLikeSeries"], CompliantLazyFrame):
     # --- not in the spec ---
     def __init__(
         self: Self,

narwhals/_pandas_like/expr.py

@@ -8,7 +8,7 @@
 from typing import Mapping
 from typing import Sequence
 
-from narwhals._compliant import CompliantExpr
+from narwhals._compliant import EagerExpr
 from narwhals._expression_parsing import ExprKind
 from narwhals._expression_parsing import evaluate_output_names_and_aliases
 from narwhals._expression_parsing import is_elementary_expression
@@ -69,7 +69,7 @@ def window_kwargs_to_pandas_equivalent(
     return pandas_kwargs
 
 
-class PandasLikeExpr(CompliantExpr["PandasLikeDataFrame", PandasLikeSeries]):
+class PandasLikeExpr(EagerExpr["PandasLikeDataFrame", PandasLikeSeries]):
     def __init__(
         self: Self,
         call: Callable[[PandasLikeDataFrame], Sequence[PandasLikeSeries]],

narwhals/_pandas_like/namespace.py

@@ -11,7 +11,7 @@
 from typing import Literal
 from typing import Sequence
 
-from narwhals._compliant import CompliantNamespace
+from narwhals._compliant import EagerNamespace
 from narwhals._expression_parsing import combine_alias_output_names
 from narwhals._expression_parsing import combine_evaluate_output_names
 from narwhals._pandas_like.dataframe import PandasLikeDataFrame
@@ -40,7 +40,15 @@
     _Scalar: TypeAlias = Any
 
 
-class PandasLikeNamespace(CompliantNamespace[PandasLikeDataFrame, PandasLikeSeries]):
+class PandasLikeNamespace(EagerNamespace[PandasLikeDataFrame, PandasLikeSeries]):
+    @property
+    def _expr(self) -> type[PandasLikeExpr]:
+        return PandasLikeExpr
+
+    @property
+    def _series(self) -> type[PandasLikeSeries]:
+        return PandasLikeSeries
+
     @property
     def selectors(self: Self) -> PandasSelectorNamespace:
         return PandasSelectorNamespace(self)

narwhals/_pandas_like/series.py

@@ -9,6 +9,7 @@
 from typing import cast
 from typing import overload
 
+from narwhals._compliant import EagerSeries
 from narwhals._pandas_like.series_cat import PandasLikeSeriesCatNamespace
 from narwhals._pandas_like.series_dt import PandasLikeSeriesDateTimeNamespace
 from narwhals._pandas_like.series_list import PandasLikeSeriesListNamespace
@@ -24,7 +25,6 @@
 from narwhals._pandas_like.utils import set_index
 from narwhals.dependencies import is_numpy_scalar
 from narwhals.exceptions import InvalidOperationError
-from narwhals.typing import CompliantSeries
 from narwhals.utils import Implementation
 from narwhals.utils import import_dtypes_module
 from narwhals.utils import validate_backend_version
@@ -90,7 +90,7 @@
 }
 
 
-class PandasLikeSeries(CompliantSeries):
+class PandasLikeSeries(EagerSeries[Any]):
     def __init__(
         self: Self,
         native_series: Any,
@@ -112,6 +112,10 @@ def __init__(
         # the length of the whole dataframe, we just extract the scalar.
         self._broadcast = False
 
+    @property
+    def native(self) -> Any:
+        return self._native_series
+
     def __native_namespace__(self: Self) -> ModuleType:
         if self._implementation in {
             Implementation.PANDAS,
@@ -139,7 +143,7 @@ def __getitem__(self: Self, idx: int | slice | Sequence[int]) -> Any | Self:
 
     def _change_version(self: Self, version: Version) -> Self:
         return self.__class__(
-            self._native_series,
+            self.native,
             implementation=self._implementation,
             backend_version=self._backend_version,
             version=version,