fix tests

narwhals/stable/v1/__init__.py

@@ -49,7 +49,7 @@
 from narwhals.translate import _from_native_impl
 from narwhals.translate import get_native_namespace as nw_get_native_namespace
 from narwhals.translate import to_native
-from narwhals.translate import to_py_scalar
+from narwhals.translate import to_py_scalar as _to_py_scalar_impl
 from narwhals.typing import IntoDataFrameT
 from narwhals.typing import IntoFrameT
 from narwhals.utils import is_ordered_categorical as nw_is_ordered_categorical
@@ -949,6 +949,25 @@ def wrapper(*args: Any, **kwargs: Any) -> Any:
         return decorator(func)
 
 
+def to_py_scalar(scalar: Any) -> Any:
+    """If a scalar is not Python native, tries to convert it to Python native.
+
+    Examples:
+        >>> import narwhals.stable.v1 as nw
+        >>> import pandas as pd
+        >>> df = nw.from_native(pd.DataFrame({"a": [1, 2, 3]}))
+        >>> nw.to_py_scalar(df["a"].item(0))
+        1
+        >>> import pyarrow as pa
+        >>> df = nw.from_native(pa.table({"a": [1, 2, 3]}))
+        >>> nw.to_py_scalar(df["a"].item(0))
+        1
+        >>> nw.to_py_scalar(1)
+        1
+    """
+    return _stableify(_to_py_scalar_impl(scalar))
+
+
 def all() -> Expr:
     """
     Instantiate an expression representing all columns.

tests/translate/to_py_scalar_test.py

@@ -1,4 +1,5 @@
 import narwhals as nw
+from narwhals.dependencies import get_cudf
 from narwhals.dependencies import get_cupy
 from tests.utils import Constructor
 
@@ -8,7 +9,8 @@ def test_to_py_scalar(constructor_eager: Constructor) -> None:
     assert nw.to_py_scalar(df["a"].item(0)) == 1
 
 
-def test_to_py_scalar_cudf_array(constructor_cudf: Constructor) -> None:
-    df = nw.from_native(constructor_cudf({"a": [1, 2, 3]}))
-    if cupy := get_cupy():
+def test_to_py_scalar_cudf_array() -> None:
+    if cudf := get_cudf():
+        cupy = get_cupy()
+        df = nw.from_native(cudf.DataFrame({"a": [1, 2, 3]}))
         assert isinstance(nw.to_py_scalar(df["a"]), cupy.ndarray)