diff --git a/doc/source/whatsnew/v3.0.0.rst b/doc/source/whatsnew/v3.0.0.rst
index b4aa6447c0a1b..e9458046f6cde 100644
--- a/doc/source/whatsnew/v3.0.0.rst
+++ b/doc/source/whatsnew/v3.0.0.rst
@@ -68,6 +68,7 @@ Other enhancements
- :func:`read_parquet` accepts ``to_pandas_kwargs`` which are forwarded to :meth:`pyarrow.Table.to_pandas` which enables passing additional keywords to customize the conversion to pandas, such as ``maps_as_pydicts`` to read the Parquet map data type as python dictionaries (:issue:`56842`)
- :meth:`.DataFrameGroupBy.transform`, :meth:`.SeriesGroupBy.transform`, :meth:`.DataFrameGroupBy.agg`, :meth:`.SeriesGroupBy.agg`, :meth:`.SeriesGroupBy.apply`, :meth:`.DataFrameGroupBy.apply` now support ``kurt`` (:issue:`40139`)
- :meth:`DataFrame.apply` supports using third-party execution engines like the Bodo.ai JIT compiler (:issue:`60668`)
+- :meth:`DataFrame.iloc` and :meth:`Series.iloc` now support boolean masks in ``__getitem__`` for more consistent indexing behavior (:issue:`60994`)
- :meth:`DataFrameGroupBy.transform`, :meth:`SeriesGroupBy.transform`, :meth:`DataFrameGroupBy.agg`, :meth:`SeriesGroupBy.agg`, :meth:`RollingGroupby.apply`, :meth:`ExpandingGroupby.apply`, :meth:`Rolling.apply`, :meth:`Expanding.apply`, :meth:`DataFrame.apply` with ``engine="numba"`` now supports positional arguments passed as kwargs (:issue:`58995`)
- :meth:`Rolling.agg`, :meth:`Expanding.agg` and :meth:`ExponentialMovingWindow.agg` now accept :class:`NamedAgg` aggregations through ``**kwargs`` (:issue:`28333`)
- :meth:`Series.map` can now accept kwargs to pass on to func (:issue:`59814`)
diff --git a/pandas/core/indexing.py b/pandas/core/indexing.py
index bcb27d0320c91..7bfafb3e17536 100644
--- a/pandas/core/indexing.py
+++ b/pandas/core/indexing.py
@@ -1582,11 +1582,7 @@ def _validate_key(self, key, axis: AxisInt) -> None:
if com.is_bool_indexer(key):
if hasattr(key, "index") and isinstance(key.index, Index):
if key.index.inferred_type == "integer":
- raise NotImplementedError(
- "iLocation based boolean "
- "indexing on an integer type "
- "is not available"
- )
+ return
raise ValueError(
"iLocation based boolean indexing cannot use an indexable as a mask"
)
diff --git a/pandas/tests/indexing/test_iloc.py b/pandas/tests/indexing/test_iloc.py
index 2f6998a85c80b..3be69617cad43 100644
--- a/pandas/tests/indexing/test_iloc.py
+++ b/pandas/tests/indexing/test_iloc.py
@@ -726,15 +726,16 @@ def test_iloc_setitem_with_scalar_index(self, indexer, value):
@pytest.mark.filterwarnings("ignore::UserWarning")
def test_iloc_mask(self):
- # GH 3631, iloc with a mask (of a series) should raise
+ # GH 60994, iloc with a mask (of a series) should return accordingly
df = DataFrame(list(range(5)), index=list("ABCDE"), columns=["a"])
mask = df.a % 2 == 0
msg = "iLocation based boolean indexing cannot use an indexable as a mask"
with pytest.raises(ValueError, match=msg):
df.iloc[mask]
+
mask.index = range(len(mask))
- msg = "iLocation based boolean indexing on an integer type is not available"
- with pytest.raises(NotImplementedError, match=msg):
+ msg = "Unalignable boolean Series provided as indexer"
+ with pytest.raises(IndexingError, match=msg):
df.iloc[mask]
# ndarray ok
@@ -753,18 +754,13 @@ def test_iloc_mask(self):
(None, ".iloc"): "0b1100",
("index", ""): "0b11",
("index", ".loc"): "0b11",
- ("index", ".iloc"): (
- "iLocation based boolean indexing cannot use an indexable as a mask"
- ),
- ("locs", ""): "Unalignable boolean Series provided as indexer "
- "(index of the boolean Series and of the indexed "
- "object do not match).",
- ("locs", ".loc"): "Unalignable boolean Series provided as indexer "
- "(index of the boolean Series and of the "
- "indexed object do not match).",
- ("locs", ".iloc"): (
- "iLocation based boolean indexing on an integer type is not available"
- ),
+ (
+ "index",
+ ".iloc",
+ ): "iLocation based boolean indexing cannot use an indexable as a mask",
+ ("locs", ""): "Unalignable boolean Series provided as indexer",
+ ("locs", ".loc"): "Unalignable boolean Series provided as indexer",
+ ("locs", ".iloc"): "Unalignable boolean Series provided as indexer",
}
# UserWarnings from reindex of a boolean mask
@@ -780,18 +776,52 @@ def test_iloc_mask(self):
else:
accessor = df
answer = str(bin(accessor[mask]["nums"].sum()))
- except (ValueError, IndexingError, NotImplementedError) as err:
+ except (ValueError, IndexingError) as err:
answer = str(err)
key = (
idx,
method,
)
- r = expected.get(key)
- if r != answer:
- raise AssertionError(
- f"[{key}] does not match [{answer}], received [{r}]"
+ expected_result = expected.get(key)
+
+ # Fix the assertion to check for substring match
+ if (
+ idx is None or (idx == "index" and method != ".iloc")
+ ) and "0b" in expected_result:
+ # For successful numeric results, exact match is needed
+ assert expected_result == answer, (
+ f"[{key}] does not match [{answer}]"
)
+ else:
+ # For error messages, substring match is sufficient
+ assert expected_result in answer, f"[{key}] not found in [{answer}]"
+
+ def test_iloc_with_numpy_bool_array(self):
+ df = DataFrame(list(range(5)), index=list("ABCDE"), columns=["a"])
+ result = df.iloc[np.array([True, False, True, False, True], dtype=bool)]
+ expected = DataFrame({"a": [0, 2, 4]}, index=["A", "C", "E"])
+ tm.assert_frame_equal(result, expected)
+
+ def test_iloc_series_mask_with_index_mismatch_raises(self):
+ df = DataFrame(list(range(5)), index=list("ABCDE"), columns=["a"])
+ mask = df.a % 2 == 0
+ msg = "Unalignable boolean Series provided as indexer"
+ with pytest.raises(IndexingError, match=msg):
+ df.iloc[Series([True] * len(mask), dtype=bool)]
+
+ def test_iloc_series_mask_all_true(self):
+ df = DataFrame(list(range(5)), columns=["a"])
+ mask = Series([True] * len(df), dtype=bool)
+ result = df.iloc[mask]
+ tm.assert_frame_equal(result, df)
+
+ def test_iloc_series_mask_alternate_true(self):
+ df = DataFrame(list(range(5)), columns=["a"])
+ mask = Series([True, False, True, False, True], dtype=bool)
+ result = df.iloc[mask]
+ expected = DataFrame({"a": [0, 2, 4]}, index=[0, 2, 4])
+ tm.assert_frame_equal(result, expected)
def test_iloc_non_unique_indexing(self):
# GH 4017, non-unique indexing (on the axis)