Update list accessor tests

Author: WillAyd

pandas/core/arrays/arrow/accessors.py

@@ -18,6 +18,8 @@
 
 from pandas.core.dtypes.common import is_list_like
 
+from pandas.core.arrays.list_ import ListDtype
+
 if not pa_version_under10p1:
     import pyarrow as pa
     import pyarrow.compute as pc
@@ -106,7 +108,7 @@ def len(self) -> Series:
         ...         [1, 2, 3],
         ...         [3],
         ...     ],
-        ...     dtype=pd.ArrowDtype(pa.list_(pa.int64())),
+        ...     dtype=pd.ListDtype(pa.int64()),
         ... )
         >>> s.list.len()
         0    3
@@ -189,7 +191,7 @@ def __getitem__(self, key: int | slice) -> Series:
             sliced = pc.list_slice(self._pa_array, start, stop, step)
             return Series(
                 sliced,
-                dtype=ArrowDtype(sliced.type),
+                dtype=ListDtype(sliced.type.value_type),
                 index=self._data.index,
                 name=self._data.name,
             )

pandas/core/arrays/list_.py

@@ -186,11 +186,7 @@ def _from_sequence(cls, scalars, *, dtype=None, copy: bool = False):
             # TypeError: object of type 'NoneType' has no len() if you have
             # pa.ListScalar(None). Upstream issue in Arrow - see:
             # https://github.com/apache/arrow/issues/40319
-            for i in range(len(scalars)):
-                if not scalars[i].is_valid:
-                    scalars[i] = None
-
-            values = pa.array(scalars, from_pandas=True)
+            values = pa.array(scalars.to_pylist(), from_pandas=True)
 
         if values.type == "null" and dtype is not None:
             pa_type = string_to_pyarrow_type(str(dtype))

pandas/tests/series/accessors/test_list_accessor.py

@@ -4,6 +4,7 @@
 
 from pandas import (
     ArrowDtype,
+    ListDtype,
     Series,
 )
 import pandas._testing as tm
@@ -16,15 +17,16 @@
 @pytest.mark.parametrize(
     "list_dtype",
     (
-        pa.list_(pa.int64()),
-        pa.list_(pa.int64(), list_size=3),
-        pa.large_list(pa.int64()),
+        ArrowDtype(pa.list_(pa.int64())),
+        ArrowDtype(pa.list_(pa.int64(), list_size=3)),
+        ArrowDtype(pa.large_list(pa.int64())),
+        ListDtype(pa.int64()),
     ),
 )
 def test_list_getitem(list_dtype):
     ser = Series(
         [[1, 2, 3], [4, None, 5], None],
-        dtype=ArrowDtype(list_dtype),
+        dtype=list_dtype,
         name="a",
     )
     actual = ser.list[1]
@@ -36,7 +38,7 @@ def test_list_getitem_index():
     # GH 58425
     ser = Series(
         [[1, 2, 3], [4, None, 5], None],
-        dtype=ArrowDtype(pa.list_(pa.int64())),
+        dtype=ListDtype(pa.int64()),
         index=[1, 3, 7],
         name="a",
     )
@@ -53,7 +55,7 @@ def test_list_getitem_index():
 def test_list_getitem_slice():
     ser = Series(
         [[1, 2, 3], [4, None, 5], None],
-        dtype=ArrowDtype(pa.list_(pa.int64())),
+        dtype=ListDtype(pa.int64()),
         index=[1, 3, 7],
         name="a",
     )
@@ -66,7 +68,7 @@ def test_list_getitem_slice():
         actual = ser.list[1:None:None]
         expected = Series(
             [[2, 3], [None, 5], None],
-            dtype=ArrowDtype(pa.list_(pa.int64())),
+            dtype=ListDtype(pa.int64()),
             index=[1, 3, 7],
             name="a",
         )
@@ -76,18 +78,18 @@ def test_list_getitem_slice():
 def test_list_len():
     ser = Series(
         [[1, 2, 3], [4, None], None],
-        dtype=ArrowDtype(pa.list_(pa.int64())),
+        dtype=ListDtype(pa.int64()),
         name="a",
     )
     actual = ser.list.len()
-    expected = Series([3, 2, None], dtype=ArrowDtype(pa.int32()), name="a")
+    expected = Series([3, 2, None], dtype=ArrowDtype(pa.int64()), name="a")
     tm.assert_series_equal(actual, expected)
 
 
 def test_list_flatten():
     ser = Series(
         [[1, 2, 3], None, [4, None], [], [7, 8]],
-        dtype=ArrowDtype(pa.list_(pa.int64())),
+        dtype=ListDtype(pa.int64()),
         name="a",
     )
     actual = ser.list.flatten()
@@ -103,7 +105,7 @@ def test_list_flatten():
 def test_list_getitem_slice_invalid():
     ser = Series(
         [[1, 2, 3], [4, None, 5], None],
-        dtype=ArrowDtype(pa.list_(pa.int64())),
+        dtype=ListDtype(pa.int64()),
     )
     if pa_version_under11p0:
         with pytest.raises(
@@ -133,15 +135,16 @@ def test_list_accessor_non_list_dtype():
 @pytest.mark.parametrize(
     "list_dtype",
     (
-        pa.list_(pa.int64()),
-        pa.list_(pa.int64(), list_size=3),
-        pa.large_list(pa.int64()),
+        ArrowDtype(pa.list_(pa.int64())),
+        ArrowDtype(pa.list_(pa.int64(), list_size=3)),
+        ArrowDtype(pa.large_list(pa.int64())),
+        ListDtype(pa.int64()),
     ),
 )
 def test_list_getitem_invalid_index(list_dtype):
     ser = Series(
         [[1, 2, 3], [4, None, 5], None],
-        dtype=ArrowDtype(list_dtype),
+        dtype=list_dtype,
     )
     with pytest.raises(pa.lib.ArrowInvalid, match="Index -1 is out of bounds"):
         ser.list[-1]
@@ -154,7 +157,7 @@ def test_list_getitem_invalid_index(list_dtype):
 def test_list_accessor_not_iterable():
     ser = Series(
         [[1, 2, 3], [4, None], None],
-        dtype=ArrowDtype(pa.list_(pa.int64())),
+        dtype=ListDtype(pa.int64()),
     )
     with pytest.raises(TypeError, match="'ListAccessor' object is not iterable"):
         iter(ser.list)