perf: remove all loc[:, ...] where assignment does not occur for

pandas backend
aivanoved · Sep 25, 2024 · 1eff960 · 1eff960
1 parent 0350661
commit 1eff960
Show file tree

Hide file tree

Showing 4 changed files with 5 additions and 5 deletions.
diff --git a/narwhals/_pandas_like/dataframe.py b/narwhals/_pandas_like/dataframe.py
@@ -98,7 +98,7 @@ 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,
         )

diff --git a/narwhals/_pandas_like/expr.py b/narwhals/_pandas_like/expr.py
@@ -64,7 +64,7 @@ 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,
                 )

diff --git a/narwhals/_pandas_like/group_by.py b/narwhals/_pandas_like/group_by.py
@@ -33,7 +33,7 @@ def __init__(self, df: PandasLikeDataFrame, keys: list[str]) -> None:
             self._df._implementation is Implementation.PANDAS
             and self._df._backend_version < (1, 0)
         ):  # pragma: no cover
-            if self._df._native_frame.loc[:, self._keys].isna().any().any():
+            if self._df._native_frame[self._keys].isna().any().any():
                 msg = "Grouping by null values is not supported in pandas < 1.0.0"
                 raise NotImplementedError(msg)
             self._grouped = self._df._native_frame.groupby(
@@ -210,7 +210,7 @@ def agg_pandas(  # noqa: PLR0915
         else:
             # No aggregation provided
             result_aggs = native_namespace.DataFrame(grouped.groups.keys(), columns=keys)
-        return from_dataframe(result_aggs.loc[:, output_names])
+        return from_dataframe(result_aggs[output_names])
 
     if dataframe_is_empty:
         # Don't even attempt this, it's way too inconsistent across pandas versions.

diff --git a/narwhals/_pandas_like/namespace.py b/narwhals/_pandas_like/namespace.py
@@ -116,7 +116,7 @@ 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,
                 )