refactor: Rename as _concat_{ConcatMethod}

- More discoverable as related methods
- Aligns a bit closer to https://github.com/pola-rs/polars/blob/ecfb7b5e09fd074ede5bd270453237d982495328/py-polars/polars/functions/eager.py#L241

Author: dangotbanned

narwhals/_pandas_like/dataframe.py

@@ -504,7 +504,7 @@ def select(self: PandasLikeDataFrame, *exprs: PandasLikeExpr) -> PandasLikeDataF
             return self._with_native(self.native.__class__(), validate_column_names=False)
         new_series = align_series_full_broadcast(*new_series)
         namespace = self.__narwhals_namespace__()
-        df = namespace._horizontal_concat([s.native for s in new_series])
+        df = namespace._concat_horizontal([s.native for s in new_series])
         return self._with_native(df, validate_column_names=True)
 
     def drop_nulls(
@@ -527,7 +527,7 @@ def with_row_index(self: Self, name: str) -> Self:
         row_index = namespace._series.from_iterable(
             range(len(frame)), context=self, index=frame.index
         ).alias(name)
-        return self._with_native(namespace._horizontal_concat([row_index.native, frame]))
+        return self._with_native(namespace._concat_horizontal([row_index.native, frame]))
 
     def row(self: Self, index: int) -> tuple[Any, ...]:
         return tuple(x for x in self.native.iloc[index])
@@ -562,7 +562,7 @@ def with_columns(
             to_concat.append(series)
         to_concat.extend(self._extract_comparand(s) for s in name_columns.values())
         namespace = self.__narwhals_namespace__()
-        df = namespace._horizontal_concat(to_concat)
+        df = namespace._concat_horizontal(to_concat)
         return self._with_native(df, validate_column_names=False)
 
     def rename(self: Self, mapping: Mapping[str, str]) -> Self:

narwhals/_pandas_like/group_by.py

@@ -233,7 +233,7 @@ def agg(self: Self, *exprs: PandasLikeExpr) -> PandasLikeDataFrame:  # noqa: PLR
                     msg = f"Expected unique output names, got:{msg}"
                     raise ValueError(msg)
                 namespace = self.compliant.__narwhals_namespace__()
-                result = namespace._horizontal_concat(result_aggs)
+                result = namespace._concat_horizontal(result_aggs)
             else:
                 # No aggregation provided
                 result = self.compliant.__native_namespace__().DataFrame(

narwhals/_pandas_like/namespace.py

@@ -223,7 +223,16 @@ def func(df: PandasLikeDataFrame) -> list[PandasLikeSeries]:
             context=self,
         )
 
-    def _horizontal_concat(self, dfs: Sequence[NDFrameT], /) -> NDFrameT:
+    def _concat_diagonal(self, dfs: Sequence[NDFrameT], /) -> NDFrameT:
+        """Concatenate (native) DataFrames diagonally."""
+        concat = self._implementation.to_native_namespace().concat
+        if self._implementation.is_pandas() and self._backend_version < (3,):
+            if self._backend_version < (1,):
+                return concat(dfs, axis=0, copy=False, sort=False)
+            return concat(dfs, axis=0, copy=False)
+        return concat(dfs, axis=0)
+
+    def _concat_horizontal(self, dfs: Sequence[NDFrameT], /) -> NDFrameT:
         """Concatenate (native) DataFrames horizontally."""
         concat = self._implementation.to_native_namespace().concat
         if self._implementation.is_cudf():
@@ -238,16 +247,7 @@ def _horizontal_concat(self, dfs: Sequence[NDFrameT], /) -> NDFrameT:
             return concat(dfs, axis=1, copy=False)
         return concat(dfs, axis=1)
 
-    def _diagonal_concat(self, dfs: Sequence[NDFrameT], /) -> NDFrameT:
-        """Concatenate (native) DataFrames diagonally."""
-        concat = self._implementation.to_native_namespace().concat
-        if self._implementation.is_pandas() and self._backend_version < (3,):
-            if self._backend_version < (1,):
-                return concat(dfs, axis=0, copy=False, sort=False)
-            return concat(dfs, axis=0, copy=False)
-        return concat(dfs, axis=0)
-
-    def _vertical_concat(self, dfs: Sequence[pd.DataFrame], /) -> pd.DataFrame:
+    def _concat_vertical(self, dfs: Sequence[pd.DataFrame], /) -> pd.DataFrame:
         """Concatenate (native) DataFrames vertically."""
         concat = self._implementation.to_native_namespace().concat
         cols_0 = dfs[0].columns
@@ -271,11 +271,11 @@ def concat(
     ) -> PandasLikeDataFrame:
         dfs: list[pd.DataFrame] = [item.native for item in items]
         if how == "horizontal":
-            native = self._horizontal_concat(dfs)
+            native = self._concat_horizontal(dfs)
         elif how == "vertical":
-            native = self._vertical_concat(dfs)
+            native = self._concat_vertical(dfs)
         elif how == "diagonal":
-            native = self._diagonal_concat(dfs)
+            native = self._concat_diagonal(dfs)
         else:
             raise NotImplementedError
         return PandasLikeDataFrame.from_native(native, context=self)