perf: Impove pandas-backend indexing (#993)

--------- Co-authored-by: Marco Gorelli <[email protected]>
narwhals-dev · Oct 6, 2024 · a2ef4fe · a2ef4fe
1 parent 8f2e834
commit a2ef4fe
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Showing 3 changed files with 7 additions and 7 deletions.
diff --git a/narwhals/_pandas_like/dataframe.py b/narwhals/_pandas_like/dataframe.py
@@ -104,7 +104,7 @@ def get_column(self, name: str) -> PandasLikeSeries:
         from narwhals._pandas_like.series import PandasLikeSeries
 
         return PandasLikeSeries(
-            self._native_frame.loc[:, name],
+            self._native_frame[name],
             implementation=self._implementation,
             backend_version=self._backend_version,
             dtypes=self._dtypes,
@@ -157,7 +157,7 @@ def __getitem__(
             from narwhals._pandas_like.series import PandasLikeSeries
 
             return PandasLikeSeries(
-                self._native_frame.loc[:, item],
+                self._native_frame[item],
                 implementation=self._implementation,
                 backend_version=self._backend_version,
                 dtypes=self._dtypes,
@@ -276,7 +276,7 @@ def iter_rows(
     @property
     def schema(self) -> dict[str, DType]:
         return {
-            col: native_to_narwhals_dtype(self._native_frame.loc[:, col], self._dtypes)
+            col: native_to_narwhals_dtype(self._native_frame[col], self._dtypes)
             for col in self._native_frame.columns
         }
 
@@ -382,7 +382,7 @@ def with_columns(
                         )
                     )
                 else:
-                    to_concat.append(self._native_frame.loc[:, name])
+                    to_concat.append(self._native_frame[name])
             to_concat.extend(
                 validate_dataframe_comparand(index, new_column_name_to_new_column_map[s])
                 for s in new_column_name_to_new_column_map
@@ -637,7 +637,7 @@ def to_dict(self, *, as_series: bool = False) -> dict[str, Any]:
             # TODO(Unassigned): should this return narwhals series?
             return {
                 col: PandasLikeSeries(
-                    self._native_frame.loc[:, col],
+                    self._native_frame[col],
                     implementation=self._implementation,
                     backend_version=self._backend_version,
                     dtypes=self._dtypes,

diff --git a/narwhals/_pandas_like/expr.py b/narwhals/_pandas_like/expr.py
@@ -70,7 +70,7 @@ def from_column_names(
         def func(df: PandasLikeDataFrame) -> list[PandasLikeSeries]:
             return [
                 PandasLikeSeries(
-                    df._native_frame.loc[:, column_name],
+                    df._native_frame[column_name],
                     implementation=df._implementation,
                     backend_version=df._backend_version,
                     dtypes=df._dtypes,

diff --git a/narwhals/_pandas_like/namespace.py b/narwhals/_pandas_like/namespace.py
@@ -119,7 +119,7 @@ def all(self) -> PandasLikeExpr:
         return PandasLikeExpr(
             lambda df: [
                 PandasLikeSeries(
-                    df._native_frame.loc[:, column_name],
+                    df._native_frame[column_name],
                     implementation=self._implementation,
                     backend_version=self._backend_version,
                     dtypes=self._dtypes,