Initial commit

venv/lib/python3.10/site-packages/pandas/tests/indexing/multiindex/test_chaining_and_caching.py

@@ -0,0 +1,87 @@
+import numpy as np
+import pytest
+
+from pandas._libs import index as libindex
+from pandas.errors import SettingWithCopyError
+import pandas.util._test_decorators as td
+
+from pandas import (
+    DataFrame,
+    MultiIndex,
+    Series,
+)
+import pandas._testing as tm
+
+
+def test_detect_chained_assignment(using_copy_on_write, warn_copy_on_write):
+    # Inplace ops, originally from:
+    # https://stackoverflow.com/questions/20508968/series-fillna-in-a-multiindex-dataframe-does-not-fill-is-this-a-bug
+    a = [12, 23]
+    b = [123, None]
+    c = [1234, 2345]
+    d = [12345, 23456]
+    tuples = [("eyes", "left"), ("eyes", "right"), ("ears", "left"), ("ears", "right")]
+    events = {
+        ("eyes", "left"): a,
+        ("eyes", "right"): b,
+        ("ears", "left"): c,
+        ("ears", "right"): d,
+    }
+    multiind = MultiIndex.from_tuples(tuples, names=["part", "side"])
+    zed = DataFrame(events, index=["a", "b"], columns=multiind)
+
+    if using_copy_on_write:
+        with tm.raises_chained_assignment_error():
+            zed["eyes"]["right"].fillna(value=555, inplace=True)
+    elif warn_copy_on_write:
+        with tm.assert_produces_warning(None):
+            zed["eyes"]["right"].fillna(value=555, inplace=True)
+    else:
+        msg = "A value is trying to be set on a copy of a slice from a DataFrame"
+        with pytest.raises(SettingWithCopyError, match=msg):
+            with tm.assert_produces_warning(None):
+                zed["eyes"]["right"].fillna(value=555, inplace=True)
+
+
+@td.skip_array_manager_invalid_test  # with ArrayManager df.loc[0] is not a view
+def test_cache_updating(using_copy_on_write, warn_copy_on_write):
+    # 5216
+    # make sure that we don't try to set a dead cache
+    a = np.random.default_rng(2).random((10, 3))
+    df = DataFrame(a, columns=["x", "y", "z"])
+    df_original = df.copy()
+    tuples = [(i, j) for i in range(5) for j in range(2)]
+    index = MultiIndex.from_tuples(tuples)
+    df.index = index
+
+    # setting via chained assignment
+    # but actually works, since everything is a view
+
+    with tm.raises_chained_assignment_error():
+        df.loc[0]["z"].iloc[0] = 1.0
+
+    if using_copy_on_write:
+        assert df.loc[(0, 0), "z"] == df_original.loc[0, "z"]
+    else:
+        result = df.loc[(0, 0), "z"]
+        assert result == 1
+
+    # correct setting
+    df.loc[(0, 0), "z"] = 2
+    result = df.loc[(0, 0), "z"]
+    assert result == 2
+
+
+def test_indexer_caching(monkeypatch):
+    # GH5727
+    # make sure that indexers are in the _internal_names_set
+    size_cutoff = 20
+    with monkeypatch.context():
+        monkeypatch.setattr(libindex, "_SIZE_CUTOFF", size_cutoff)
+        index = MultiIndex.from_arrays([np.arange(size_cutoff), np.arange(size_cutoff)])
+        s = Series(np.zeros(size_cutoff), index=index)
+
+        # setitem
+        s[s == 0] = 1
+    expected = Series(np.ones(size_cutoff), index=index)
+    tm.assert_series_equal(s, expected)

venv/lib/python3.10/site-packages/pandas/tests/indexing/multiindex/test_datetime.py

@@ -0,0 +1,50 @@
+from datetime import datetime
+
+import numpy as np
+
+from pandas import (
+    DataFrame,
+    Index,
+    MultiIndex,
+    Period,
+    Series,
+    period_range,
+    to_datetime,
+)
+import pandas._testing as tm
+
+
+def test_multiindex_period_datetime():
+    # GH4861, using datetime in period of multiindex raises exception
+
+    idx1 = Index(["a", "a", "a", "b", "b"])
+    idx2 = period_range("2012-01", periods=len(idx1), freq="M")
+    s = Series(np.random.default_rng(2).standard_normal(len(idx1)), [idx1, idx2])
+
+    # try Period as index
+    expected = s.iloc[0]
+    result = s.loc["a", Period("2012-01")]
+    assert result == expected
+
+    # try datetime as index
+    result = s.loc["a", datetime(2012, 1, 1)]
+    assert result == expected
+
+
+def test_multiindex_datetime_columns():
+    # GH35015, using datetime as column indices raises exception
+
+    mi = MultiIndex.from_tuples(
+        [(to_datetime("02/29/2020"), to_datetime("03/01/2020"))], names=["a", "b"]
+    )
+
+    df = DataFrame([], columns=mi)
+
+    expected_df = DataFrame(
+        [],
+        columns=MultiIndex.from_arrays(
+            [[to_datetime("02/29/2020")], [to_datetime("03/01/2020")]], names=["a", "b"]
+        ),
+    )
+
+    tm.assert_frame_equal(df, expected_df)

venv/lib/python3.10/site-packages/pandas/tests/indexing/multiindex/test_getitem.py

@@ -0,0 +1,410 @@
+import numpy as np
+import pytest
+
+from pandas import (
+    DataFrame,
+    Index,
+    MultiIndex,
+    Series,
+)
+import pandas._testing as tm
+from pandas.core.indexing import IndexingError
+
+# ----------------------------------------------------------------------------
+# test indexing of Series with multi-level Index
+# ----------------------------------------------------------------------------
+
+
+@pytest.mark.parametrize(
+    "access_method",
+    [lambda s, x: s[:, x], lambda s, x: s.loc[:, x], lambda s, x: s.xs(x, level=1)],
+)
+@pytest.mark.parametrize(
+    "level1_value, expected",
+    [(0, Series([1], index=[0])), (1, Series([2, 3], index=[1, 2]))],
+)
+def test_series_getitem_multiindex(access_method, level1_value, expected):
+    # GH 6018
+    # series regression getitem with a multi-index
+
+    mi = MultiIndex.from_tuples([(0, 0), (1, 1), (2, 1)], names=["A", "B"])
+    ser = Series([1, 2, 3], index=mi)
+    expected.index.name = "A"
+
+    result = access_method(ser, level1_value)
+    tm.assert_series_equal(result, expected)
+
+
+@pytest.mark.parametrize("level0_value", ["D", "A"])
+def test_series_getitem_duplicates_multiindex(level0_value):
+    # GH 5725 the 'A' happens to be a valid Timestamp so the doesn't raise
+    # the appropriate error, only in PY3 of course!
+
+    index = MultiIndex(
+        levels=[[level0_value, "B", "C"], [0, 26, 27, 37, 57, 67, 75, 82]],
+        codes=[[0, 0, 0, 1, 2, 2, 2, 2, 2, 2], [1, 3, 4, 6, 0, 2, 2, 3, 5, 7]],
+        names=["tag", "day"],
+    )
+    arr = np.random.default_rng(2).standard_normal((len(index), 1))
+    df = DataFrame(arr, index=index, columns=["val"])
+
+    # confirm indexing on missing value raises KeyError
+    if level0_value != "A":
+        with pytest.raises(KeyError, match=r"^'A'$"):
+            df.val["A"]
+
+    with pytest.raises(KeyError, match=r"^'X'$"):
+        df.val["X"]
+
+    result = df.val[level0_value]
+    expected = Series(
+        arr.ravel()[0:3], name="val", index=Index([26, 37, 57], name="day")
+    )
+    tm.assert_series_equal(result, expected)
+
+
+def test_series_getitem(multiindex_year_month_day_dataframe_random_data, indexer_sl):
+    s = multiindex_year_month_day_dataframe_random_data["A"]
+    expected = s.reindex(s.index[42:65])
+    expected.index = expected.index.droplevel(0).droplevel(0)
+
+    result = indexer_sl(s)[2000, 3]
+    tm.assert_series_equal(result, expected)
+
+
+def test_series_getitem_returns_scalar(
+    multiindex_year_month_day_dataframe_random_data, indexer_sl
+):
+    s = multiindex_year_month_day_dataframe_random_data["A"]
+    expected = s.iloc[49]
+
+    result = indexer_sl(s)[2000, 3, 10]
+    assert result == expected
+
+
+@pytest.mark.parametrize(
+    "indexer,expected_error,expected_error_msg",
+    [
+        (lambda s: s.__getitem__((2000, 3, 4)), KeyError, r"^\(2000, 3, 4\)$"),
+        (lambda s: s[(2000, 3, 4)], KeyError, r"^\(2000, 3, 4\)$"),
+        (lambda s: s.loc[(2000, 3, 4)], KeyError, r"^\(2000, 3, 4\)$"),
+        (lambda s: s.loc[(2000, 3, 4, 5)], IndexingError, "Too many indexers"),
+        (lambda s: s.__getitem__(len(s)), KeyError, ""),  # match should include len(s)
+        (lambda s: s[len(s)], KeyError, ""),  # match should include len(s)
+        (
+            lambda s: s.iloc[len(s)],
+            IndexError,
+            "single positional indexer is out-of-bounds",
+        ),
+    ],
+)
+def test_series_getitem_indexing_errors(
+    multiindex_year_month_day_dataframe_random_data,
+    indexer,
+    expected_error,
+    expected_error_msg,
+):
+    s = multiindex_year_month_day_dataframe_random_data["A"]
+    with pytest.raises(expected_error, match=expected_error_msg):
+        indexer(s)
+
+
+def test_series_getitem_corner_generator(
+    multiindex_year_month_day_dataframe_random_data,
+):
+    s = multiindex_year_month_day_dataframe_random_data["A"]
+    result = s[(x > 0 for x in s)]
+    expected = s[s > 0]
+    tm.assert_series_equal(result, expected)
+
+
+# ----------------------------------------------------------------------------
+# test indexing of DataFrame with multi-level Index
+# ----------------------------------------------------------------------------
+
+
+def test_getitem_simple(multiindex_dataframe_random_data):
+    df = multiindex_dataframe_random_data.T
+    expected = df.values[:, 0]
+    result = df["foo", "one"].values
+    tm.assert_almost_equal(result, expected)
+
+
+@pytest.mark.parametrize(
+    "indexer,expected_error_msg",
+    [
+        (lambda df: df[("foo", "four")], r"^\('foo', 'four'\)$"),
+        (lambda df: df["foobar"], r"^'foobar'$"),
+    ],
+)
+def test_frame_getitem_simple_key_error(
+    multiindex_dataframe_random_data, indexer, expected_error_msg
+):
+    df = multiindex_dataframe_random_data.T
+    with pytest.raises(KeyError, match=expected_error_msg):
+        indexer(df)
+
+
+def test_tuple_string_column_names():
+    # GH#50372
+    mi = MultiIndex.from_tuples([("a", "aa"), ("a", "ab"), ("b", "ba"), ("b", "bb")])
+    df = DataFrame([range(4), range(1, 5), range(2, 6)], columns=mi)
+    df["single_index"] = 0
+
+    df_flat = df.copy()
+    df_flat.columns = df_flat.columns.to_flat_index()
+    df_flat["new_single_index"] = 0
+
+    result = df_flat[[("a", "aa"), "new_single_index"]]
+    expected = DataFrame(
+        [[0, 0], [1, 0], [2, 0]], columns=Index([("a", "aa"), "new_single_index"])
+    )
+    tm.assert_frame_equal(result, expected)
+
+
+def test_frame_getitem_multicolumn_empty_level():
+    df = DataFrame({"a": ["1", "2", "3"], "b": ["2", "3", "4"]})
+    df.columns = [
+        ["level1 item1", "level1 item2"],
+        ["", "level2 item2"],
+        ["level3 item1", "level3 item2"],
+    ]
+
+    result = df["level1 item1"]
+    expected = DataFrame(
+        [["1"], ["2"], ["3"]], index=df.index, columns=["level3 item1"]
+    )
+    tm.assert_frame_equal(result, expected)
+
+
+@pytest.mark.parametrize(
+    "indexer,expected_slice",
+    [
+        (lambda df: df["foo"], slice(3)),
+        (lambda df: df["bar"], slice(3, 5)),
+        (lambda df: df.loc[:, "bar"], slice(3, 5)),
+    ],
+)
+def test_frame_getitem_toplevel(
+    multiindex_dataframe_random_data, indexer, expected_slice
+):
+    df = multiindex_dataframe_random_data.T
+    expected = df.reindex(columns=df.columns[expected_slice])
+    expected.columns = expected.columns.droplevel(0)
+    result = indexer(df)
+    tm.assert_frame_equal(result, expected)
+
+
+def test_frame_mixed_depth_get():
+    arrays = [
+        ["a", "top", "top", "routine1", "routine1", "routine2"],
+        ["", "OD", "OD", "result1", "result2", "result1"],
+        ["", "wx", "wy", "", "", ""],
+    ]
+
+    tuples = sorted(zip(*arrays))
+    index = MultiIndex.from_tuples(tuples)
+    df = DataFrame(np.random.default_rng(2).standard_normal((4, 6)), columns=index)
+
+    result = df["a"]
+    expected = df["a", "", ""].rename("a")
+    tm.assert_series_equal(result, expected)
+
+    result = df["routine1", "result1"]
+    expected = df["routine1", "result1", ""]
+    expected = expected.rename(("routine1", "result1"))
+    tm.assert_series_equal(result, expected)
+
+
+def test_frame_getitem_nan_multiindex(nulls_fixture):
+    # GH#29751
+    # loc on a multiindex containing nan values
+    n = nulls_fixture  # for code readability
+    cols = ["a", "b", "c"]
+    df = DataFrame(
+        [[11, n, 13], [21, n, 23], [31, n, 33], [41, n, 43]],
+        columns=cols,
+    ).set_index(["a", "b"])
+    df["c"] = df["c"].astype("int64")
+
+    idx = (21, n)
+    result = df.loc[:idx]
+    expected = DataFrame([[11, n, 13], [21, n, 23]], columns=cols).set_index(["a", "b"])
+    expected["c"] = expected["c"].astype("int64")
+    tm.assert_frame_equal(result, expected)
+
+    result = df.loc[idx:]
+    expected = DataFrame(
+        [[21, n, 23], [31, n, 33], [41, n, 43]], columns=cols
+    ).set_index(["a", "b"])
+    expected["c"] = expected["c"].astype("int64")
+    tm.assert_frame_equal(result, expected)
+
+    idx1, idx2 = (21, n), (31, n)
+    result = df.loc[idx1:idx2]
+    expected = DataFrame([[21, n, 23], [31, n, 33]], columns=cols).set_index(["a", "b"])
+    expected["c"] = expected["c"].astype("int64")
+    tm.assert_frame_equal(result, expected)
+
+
+@pytest.mark.parametrize(
+    "indexer,expected",
+    [
+        (
+            (["b"], ["bar", np.nan]),
+            (
+                DataFrame(
+                    [[2, 3], [5, 6]],
+                    columns=MultiIndex.from_tuples([("b", "bar"), ("b", np.nan)]),
+                    dtype="int64",
+                )
+            ),
+        ),
+        (
+            (["a", "b"]),
+            (
+                DataFrame(
+                    [[1, 2, 3], [4, 5, 6]],
+                    columns=MultiIndex.from_tuples(
+                        [("a", "foo"), ("b", "bar"), ("b", np.nan)]
+                    ),
+                    dtype="int64",
+                )
+            ),
+        ),
+        (
+            (["b"]),
+            (
+                DataFrame(
+                    [[2, 3], [5, 6]],
+                    columns=MultiIndex.from_tuples([("b", "bar"), ("b", np.nan)]),
+                    dtype="int64",
+                )
+            ),
+        ),
+        (
+            (["b"], ["bar"]),
+            (
+                DataFrame(
+                    [[2], [5]],
+                    columns=MultiIndex.from_tuples([("b", "bar")]),
+                    dtype="int64",
+                )
+            ),
+        ),
+        (
+            (["b"], [np.nan]),
+            (
+                DataFrame(
+                    [[3], [6]],
+                    columns=MultiIndex(
+                        codes=[[1], [-1]], levels=[["a", "b"], ["bar", "foo"]]
+                    ),
+                    dtype="int64",
+                )
+            ),
+        ),
+        (("b", np.nan), Series([3, 6], dtype="int64", name=("b", np.nan))),
+    ],
+)
+def test_frame_getitem_nan_cols_multiindex(
+    indexer,
+    expected,
+    nulls_fixture,
+):
+    # Slicing MultiIndex including levels with nan values, for more information
+    # see GH#25154
+    df = DataFrame(
+        [[1, 2, 3], [4, 5, 6]],
+        columns=MultiIndex.from_tuples(
+            [("a", "foo"), ("b", "bar"), ("b", nulls_fixture)]
+        ),
+        dtype="int64",
+    )
+
+    result = df.loc[:, indexer]
+    tm.assert_equal(result, expected)
+
+
+# ----------------------------------------------------------------------------
+# test indexing of DataFrame with multi-level Index with duplicates
+# ----------------------------------------------------------------------------
+
+
+@pytest.fixture
+def dataframe_with_duplicate_index():
+    """Fixture for DataFrame used in tests for gh-4145 and gh-4146"""
+    data = [["a", "d", "e", "c", "f", "b"], [1, 4, 5, 3, 6, 2], [1, 4, 5, 3, 6, 2]]
+    index = ["h1", "h3", "h5"]
+    columns = MultiIndex(
+        levels=[["A", "B"], ["A1", "A2", "B1", "B2"]],
+        codes=[[0, 0, 0, 1, 1, 1], [0, 3, 3, 0, 1, 2]],
+        names=["main", "sub"],
+    )
+    return DataFrame(data, index=index, columns=columns)
+
+
+@pytest.mark.parametrize(
+    "indexer", [lambda df: df[("A", "A1")], lambda df: df.loc[:, ("A", "A1")]]
+)
+def test_frame_mi_access(dataframe_with_duplicate_index, indexer):
+    # GH 4145
+    df = dataframe_with_duplicate_index
+    index = Index(["h1", "h3", "h5"])
+    columns = MultiIndex.from_tuples([("A", "A1")], names=["main", "sub"])
+    expected = DataFrame([["a", 1, 1]], index=columns, columns=index).T
+
+    result = indexer(df)
+    tm.assert_frame_equal(result, expected)
+
+
+def test_frame_mi_access_returns_series(dataframe_with_duplicate_index):
+    # GH 4146, not returning a block manager when selecting a unique index
+    # from a duplicate index
+    # as of 4879, this returns a Series (which is similar to what happens
+    # with a non-unique)
+    df = dataframe_with_duplicate_index
+    expected = Series(["a", 1, 1], index=["h1", "h3", "h5"], name="A1")
+    result = df["A"]["A1"]
+    tm.assert_series_equal(result, expected)
+
+
+def test_frame_mi_access_returns_frame(dataframe_with_duplicate_index):
+    # selecting a non_unique from the 2nd level
+    df = dataframe_with_duplicate_index
+    expected = DataFrame(
+        [["d", 4, 4], ["e", 5, 5]],
+        index=Index(["B2", "B2"], name="sub"),
+        columns=["h1", "h3", "h5"],
+    ).T
+    result = df["A"]["B2"]
+    tm.assert_frame_equal(result, expected)
+
+
+def test_frame_mi_empty_slice():
+    # GH 15454
+    df = DataFrame(0, index=range(2), columns=MultiIndex.from_product([[1], [2]]))
+    result = df[[]]
+    expected = DataFrame(
+        index=[0, 1], columns=MultiIndex(levels=[[1], [2]], codes=[[], []])
+    )
+    tm.assert_frame_equal(result, expected)
+
+
+def test_loc_empty_multiindex():
+    # GH#36936
+    arrays = [["a", "a", "b", "a"], ["a", "a", "b", "b"]]
+    index = MultiIndex.from_arrays(arrays, names=("idx1", "idx2"))
+    df = DataFrame([1, 2, 3, 4], index=index, columns=["value"])
+
+    # loc on empty multiindex == loc with False mask
+    empty_multiindex = df.loc[df.loc[:, "value"] == 0, :].index
+    result = df.loc[empty_multiindex, :]
+    expected = df.loc[[False] * len(df.index), :]
+    tm.assert_frame_equal(result, expected)
+
+    # replacing value with loc on empty multiindex
+    df.loc[df.loc[df.loc[:, "value"] == 0].index, "value"] = 5
+    result = df
+    expected = DataFrame([1, 2, 3, 4], index=index, columns=["value"])
+    tm.assert_frame_equal(result, expected)

venv/lib/python3.10/site-packages/pandas/tests/indexing/multiindex/test_iloc.py

@@ -0,0 +1,171 @@
+import numpy as np
+import pytest
+
+from pandas import (
+    DataFrame,
+    MultiIndex,
+    Series,
+)
+import pandas._testing as tm
+
+
+@pytest.fixture
+def simple_multiindex_dataframe():
+    """
+    Factory function to create simple 3 x 3 dataframe with
+    both columns and row MultiIndex using supplied data or
+    random data by default.
+    """
+
+    data = np.random.default_rng(2).standard_normal((3, 3))
+    return DataFrame(
+        data, columns=[[2, 2, 4], [6, 8, 10]], index=[[4, 4, 8], [8, 10, 12]]
+    )
+
+
+@pytest.mark.parametrize(
+    "indexer, expected",
+    [
+        (
+            lambda df: df.iloc[0],
+            lambda arr: Series(arr[0], index=[[2, 2, 4], [6, 8, 10]], name=(4, 8)),
+        ),
+        (
+            lambda df: df.iloc[2],
+            lambda arr: Series(arr[2], index=[[2, 2, 4], [6, 8, 10]], name=(8, 12)),
+        ),
+        (
+            lambda df: df.iloc[:, 2],
+            lambda arr: Series(arr[:, 2], index=[[4, 4, 8], [8, 10, 12]], name=(4, 10)),
+        ),
+    ],
+)
+def test_iloc_returns_series(indexer, expected, simple_multiindex_dataframe):
+    df = simple_multiindex_dataframe
+    arr = df.values
+    result = indexer(df)
+    expected = expected(arr)
+    tm.assert_series_equal(result, expected)
+
+
+def test_iloc_returns_dataframe(simple_multiindex_dataframe):
+    df = simple_multiindex_dataframe
+    result = df.iloc[[0, 1]]
+    expected = df.xs(4, drop_level=False)
+    tm.assert_frame_equal(result, expected)
+
+
+def test_iloc_returns_scalar(simple_multiindex_dataframe):
+    df = simple_multiindex_dataframe
+    arr = df.values
+    result = df.iloc[2, 2]
+    expected = arr[2, 2]
+    assert result == expected
+
+
+def test_iloc_getitem_multiple_items():
+    # GH 5528
+    tup = zip(*[["a", "a", "b", "b"], ["x", "y", "x", "y"]])
+    index = MultiIndex.from_tuples(tup)
+    df = DataFrame(np.random.default_rng(2).standard_normal((4, 4)), index=index)
+    result = df.iloc[[2, 3]]
+    expected = df.xs("b", drop_level=False)
+    tm.assert_frame_equal(result, expected)
+
+
+def test_iloc_getitem_labels():
+    # this is basically regular indexing
+    arr = np.random.default_rng(2).standard_normal((4, 3))
+    df = DataFrame(
+        arr,
+        columns=[["i", "i", "j"], ["A", "A", "B"]],
+        index=[["i", "i", "j", "k"], ["X", "X", "Y", "Y"]],
+    )
+    result = df.iloc[2, 2]
+    expected = arr[2, 2]
+    assert result == expected
+
+
+def test_frame_getitem_slice(multiindex_dataframe_random_data):
+    df = multiindex_dataframe_random_data
+    result = df.iloc[:4]
+    expected = df[:4]
+    tm.assert_frame_equal(result, expected)
+
+
+def test_frame_setitem_slice(multiindex_dataframe_random_data):
+    df = multiindex_dataframe_random_data
+    df.iloc[:4] = 0
+
+    assert (df.values[:4] == 0).all()
+    assert (df.values[4:] != 0).all()
+
+
+def test_indexing_ambiguity_bug_1678():
+    # GH 1678
+    columns = MultiIndex.from_tuples(
+        [("Ohio", "Green"), ("Ohio", "Red"), ("Colorado", "Green")]
+    )
+    index = MultiIndex.from_tuples([("a", 1), ("a", 2), ("b", 1), ("b", 2)])
+
+    df = DataFrame(np.arange(12).reshape((4, 3)), index=index, columns=columns)
+
+    result = df.iloc[:, 1]
+    expected = df.loc[:, ("Ohio", "Red")]
+    tm.assert_series_equal(result, expected)
+
+
+def test_iloc_integer_locations():
+    # GH 13797
+    data = [
+        ["str00", "str01"],
+        ["str10", "str11"],
+        ["str20", "srt21"],
+        ["str30", "str31"],
+        ["str40", "str41"],
+    ]
+
+    index = MultiIndex.from_tuples(
+        [("CC", "A"), ("CC", "B"), ("CC", "B"), ("BB", "a"), ("BB", "b")]
+    )
+
+    expected = DataFrame(data)
+    df = DataFrame(data, index=index)
+
+    result = DataFrame([[df.iloc[r, c] for c in range(2)] for r in range(5)])
+
+    tm.assert_frame_equal(result, expected)
+
+
+@pytest.mark.parametrize(
+    "data, indexes, values, expected_k",
+    [
+        # test without indexer value in first level of MultiIndex
+        ([[2, 22, 5], [2, 33, 6]], [0, -1, 1], [2, 3, 1], [7, 10]),
+        # test like code sample 1 in the issue
+        ([[1, 22, 555], [1, 33, 666]], [0, -1, 1], [200, 300, 100], [755, 1066]),
+        # test like code sample 2 in the issue
+        ([[1, 3, 7], [2, 4, 8]], [0, -1, 1], [10, 10, 1000], [17, 1018]),
+        # test like code sample 3 in the issue
+        ([[1, 11, 4], [2, 22, 5], [3, 33, 6]], [0, -1, 1], [4, 7, 10], [8, 15, 13]),
+    ],
+)
+def test_iloc_setitem_int_multiindex_series(data, indexes, values, expected_k):
+    # GH17148
+    df = DataFrame(data=data, columns=["i", "j", "k"])
+    df = df.set_index(["i", "j"])
+
+    series = df.k.copy()
+    for i, v in zip(indexes, values):
+        series.iloc[i] += v
+
+    df["k"] = expected_k
+    expected = df.k
+    tm.assert_series_equal(series, expected)
+
+
+def test_getitem_iloc(multiindex_dataframe_random_data):
+    df = multiindex_dataframe_random_data
+    result = df.iloc[2]
+    expected = df.xs(df.index[2])
+    tm.assert_series_equal(result, expected)

venv/lib/python3.10/site-packages/pandas/tests/indexing/multiindex/test_indexing_slow.py

@@ -0,0 +1,118 @@
+import numpy as np
+import pytest
+
+import pandas as pd
+from pandas import (
+    DataFrame,
+    Series,
+)
+import pandas._testing as tm
+
+
+@pytest.fixture
+def m():
+    return 5
+
+
+@pytest.fixture
+def n():
+    return 100
+
+
+@pytest.fixture
+def cols():
+    return ["jim", "joe", "jolie", "joline", "jolia"]
+
+
+@pytest.fixture
+def vals(n):
+    vals = [
+        np.random.default_rng(2).integers(0, 10, n),
+        np.random.default_rng(2).choice(list("abcdefghij"), n),
+        np.random.default_rng(2).choice(
+            pd.date_range("20141009", periods=10).tolist(), n
+        ),
+        np.random.default_rng(2).choice(list("ZYXWVUTSRQ"), n),
+        np.random.default_rng(2).standard_normal(n),
+    ]
+    vals = list(map(tuple, zip(*vals)))
+    return vals
+
+
+@pytest.fixture
+def keys(n, m, vals):
+    # bunch of keys for testing
+    keys = [
+        np.random.default_rng(2).integers(0, 11, m),
+        np.random.default_rng(2).choice(list("abcdefghijk"), m),
+        np.random.default_rng(2).choice(
+            pd.date_range("20141009", periods=11).tolist(), m
+        ),
+        np.random.default_rng(2).choice(list("ZYXWVUTSRQP"), m),
+    ]
+    keys = list(map(tuple, zip(*keys)))
+    keys += [t[:-1] for t in vals[:: n // m]]
+    return keys
+
+
+# covers both unique index and non-unique index
+@pytest.fixture
+def df(vals, cols):
+    return DataFrame(vals, columns=cols)
+
+
+@pytest.fixture
+def a(df):
+    return pd.concat([df, df])
+
+
+@pytest.fixture
+def b(df, cols):
+    return df.drop_duplicates(subset=cols[:-1])
+
+
+@pytest.mark.filterwarnings("ignore::pandas.errors.PerformanceWarning")
+@pytest.mark.parametrize("lexsort_depth", list(range(5)))
+@pytest.mark.parametrize("frame_fixture", ["a", "b"])
+def test_multiindex_get_loc(request, lexsort_depth, keys, frame_fixture, cols):
+    # GH7724, GH2646
+
+    frame = request.getfixturevalue(frame_fixture)
+    if lexsort_depth == 0:
+        df = frame.copy(deep=False)
+    else:
+        df = frame.sort_values(by=cols[:lexsort_depth])
+
+    mi = df.set_index(cols[:-1])
+    assert not mi.index._lexsort_depth < lexsort_depth
+    for key in keys:
+        mask = np.ones(len(df), dtype=bool)
+
+        # test for all partials of this key
+        for i, k in enumerate(key):
+            mask &= df.iloc[:, i] == k
+
+            if not mask.any():
+                assert key[: i + 1] not in mi.index
+                continue
+
+            assert key[: i + 1] in mi.index
+            right = df[mask].copy(deep=False)
+
+            if i + 1 != len(key):  # partial key
+                return_value = right.drop(cols[: i + 1], axis=1, inplace=True)
+                assert return_value is None
+                return_value = right.set_index(cols[i + 1 : -1], inplace=True)
+                assert return_value is None
+                tm.assert_frame_equal(mi.loc[key[: i + 1]], right)
+
+            else:  # full key
+                return_value = right.set_index(cols[:-1], inplace=True)
+                assert return_value is None
+                if len(right) == 1:  # single hit
+                    right = Series(
+                        right["jolia"].values, name=right.index[0], index=["jolia"]
+                    )
+                    tm.assert_series_equal(mi.loc[key[: i + 1]], right)
+                else:  # multi hit
+                    tm.assert_frame_equal(mi.loc[key[: i + 1]], right)

venv/lib/python3.10/site-packages/pandas/tests/indexing/multiindex/test_multiindex.py

@@ -0,0 +1,235 @@
+import numpy as np
+import pytest
+
+import pandas._libs.index as libindex
+from pandas.errors import PerformanceWarning
+
+import pandas as pd
+from pandas import (
+    CategoricalDtype,
+    DataFrame,
+    Index,
+    MultiIndex,
+    Series,
+)
+import pandas._testing as tm
+from pandas.core.arrays.boolean import BooleanDtype
+
+
+class TestMultiIndexBasic:
+    def test_multiindex_perf_warn(self):
+        df = DataFrame(
+            {
+                "jim": [0, 0, 1, 1],
+                "joe": ["x", "x", "z", "y"],
+                "jolie": np.random.default_rng(2).random(4),
+            }
+        ).set_index(["jim", "joe"])
+
+        with tm.assert_produces_warning(PerformanceWarning):
+            df.loc[(1, "z")]
+
+        df = df.iloc[[2, 1, 3, 0]]
+        with tm.assert_produces_warning(PerformanceWarning):
+            df.loc[(0,)]
+
+    @pytest.mark.parametrize("offset", [-5, 5])
+    def test_indexing_over_hashtable_size_cutoff(self, monkeypatch, offset):
+        size_cutoff = 20
+        n = size_cutoff + offset
+
+        with monkeypatch.context():
+            monkeypatch.setattr(libindex, "_SIZE_CUTOFF", size_cutoff)
+            s = Series(np.arange(n), MultiIndex.from_arrays((["a"] * n, np.arange(n))))
+
+            # hai it works!
+            assert s[("a", 5)] == 5
+            assert s[("a", 6)] == 6
+            assert s[("a", 7)] == 7
+
+    def test_multi_nan_indexing(self):
+        # GH 3588
+        df = DataFrame(
+            {
+                "a": ["R1", "R2", np.nan, "R4"],
+                "b": ["C1", "C2", "C3", "C4"],
+                "c": [10, 15, np.nan, 20],
+            }
+        )
+        result = df.set_index(["a", "b"], drop=False)
+        expected = DataFrame(
+            {
+                "a": ["R1", "R2", np.nan, "R4"],
+                "b": ["C1", "C2", "C3", "C4"],
+                "c": [10, 15, np.nan, 20],
+            },
+            index=[
+                Index(["R1", "R2", np.nan, "R4"], name="a"),
+                Index(["C1", "C2", "C3", "C4"], name="b"),
+            ],
+        )
+        tm.assert_frame_equal(result, expected)
+
+    def test_exclusive_nat_column_indexing(self):
+        # GH 38025
+        # test multi indexing when one column exclusively contains NaT values
+        df = DataFrame(
+            {
+                "a": [pd.NaT, pd.NaT, pd.NaT, pd.NaT],
+                "b": ["C1", "C2", "C3", "C4"],
+                "c": [10, 15, np.nan, 20],
+            }
+        )
+        df = df.set_index(["a", "b"])
+        expected = DataFrame(
+            {
+                "c": [10, 15, np.nan, 20],
+            },
+            index=[
+                Index([pd.NaT, pd.NaT, pd.NaT, pd.NaT], name="a"),
+                Index(["C1", "C2", "C3", "C4"], name="b"),
+            ],
+        )
+        tm.assert_frame_equal(df, expected)
+
+    def test_nested_tuples_duplicates(self):
+        # GH#30892
+
+        dti = pd.to_datetime(["20190101", "20190101", "20190102"])
+        idx = Index(["a", "a", "c"])
+        mi = MultiIndex.from_arrays([dti, idx], names=["index1", "index2"])
+
+        df = DataFrame({"c1": [1, 2, 3], "c2": [np.nan, np.nan, np.nan]}, index=mi)
+
+        expected = DataFrame({"c1": df["c1"], "c2": [1.0, 1.0, np.nan]}, index=mi)
+
+        df2 = df.copy(deep=True)
+        df2.loc[(dti[0], "a"), "c2"] = 1.0
+        tm.assert_frame_equal(df2, expected)
+
+        df3 = df.copy(deep=True)
+        df3.loc[[(dti[0], "a")], "c2"] = 1.0
+        tm.assert_frame_equal(df3, expected)
+
+    def test_multiindex_with_datatime_level_preserves_freq(self):
+        # https://github.com/pandas-dev/pandas/issues/35563
+        idx = Index(range(2), name="A")
+        dti = pd.date_range("2020-01-01", periods=7, freq="D", name="B")
+        mi = MultiIndex.from_product([idx, dti])
+        df = DataFrame(np.random.default_rng(2).standard_normal((14, 2)), index=mi)
+        result = df.loc[0].index
+        tm.assert_index_equal(result, dti)
+        assert result.freq == dti.freq
+
+    def test_multiindex_complex(self):
+        # GH#42145
+        complex_data = [1 + 2j, 4 - 3j, 10 - 1j]
+        non_complex_data = [3, 4, 5]
+        result = DataFrame(
+            {
+                "x": complex_data,
+                "y": non_complex_data,
+                "z": non_complex_data,
+            }
+        )
+        result.set_index(["x", "y"], inplace=True)
+        expected = DataFrame(
+            {"z": non_complex_data},
+            index=MultiIndex.from_arrays(
+                [complex_data, non_complex_data],
+                names=("x", "y"),
+            ),
+        )
+        tm.assert_frame_equal(result, expected)
+
+    def test_rename_multiindex_with_duplicates(self):
+        # GH 38015
+        mi = MultiIndex.from_tuples([("A", "cat"), ("B", "cat"), ("B", "cat")])
+        df = DataFrame(index=mi)
+        df = df.rename(index={"A": "Apple"}, level=0)
+
+        mi2 = MultiIndex.from_tuples([("Apple", "cat"), ("B", "cat"), ("B", "cat")])
+        expected = DataFrame(index=mi2)
+        tm.assert_frame_equal(df, expected)
+
+    def test_series_align_multiindex_with_nan_overlap_only(self):
+        # GH 38439
+        mi1 = MultiIndex.from_arrays([[81.0, np.nan], [np.nan, np.nan]])
+        mi2 = MultiIndex.from_arrays([[np.nan, 82.0], [np.nan, np.nan]])
+        ser1 = Series([1, 2], index=mi1)
+        ser2 = Series([1, 2], index=mi2)
+        result1, result2 = ser1.align(ser2)
+
+        mi = MultiIndex.from_arrays([[81.0, 82.0, np.nan], [np.nan, np.nan, np.nan]])
+        expected1 = Series([1.0, np.nan, 2.0], index=mi)
+        expected2 = Series([np.nan, 2.0, 1.0], index=mi)
+
+        tm.assert_series_equal(result1, expected1)
+        tm.assert_series_equal(result2, expected2)
+
+    def test_series_align_multiindex_with_nan(self):
+        # GH 38439
+        mi1 = MultiIndex.from_arrays([[81.0, np.nan], [np.nan, np.nan]])
+        mi2 = MultiIndex.from_arrays([[np.nan, 81.0], [np.nan, np.nan]])
+        ser1 = Series([1, 2], index=mi1)
+        ser2 = Series([1, 2], index=mi2)
+        result1, result2 = ser1.align(ser2)
+
+        mi = MultiIndex.from_arrays([[81.0, np.nan], [np.nan, np.nan]])
+        expected1 = Series([1, 2], index=mi)
+        expected2 = Series([2, 1], index=mi)
+
+        tm.assert_series_equal(result1, expected1)
+        tm.assert_series_equal(result2, expected2)
+
+    def test_nunique_smoke(self):
+        # GH 34019
+        n = DataFrame([[1, 2], [1, 2]]).set_index([0, 1]).index.nunique()
+        assert n == 1
+
+    def test_multiindex_repeated_keys(self):
+        # GH19414
+        tm.assert_series_equal(
+            Series([1, 2], MultiIndex.from_arrays([["a", "b"]])).loc[
+                ["a", "a", "b", "b"]
+            ],
+            Series([1, 1, 2, 2], MultiIndex.from_arrays([["a", "a", "b", "b"]])),
+        )
+
+    def test_multiindex_with_na_missing_key(self):
+        # GH46173
+        df = DataFrame.from_dict(
+            {
+                ("foo",): [1, 2, 3],
+                ("bar",): [5, 6, 7],
+                (None,): [8, 9, 0],
+            }
+        )
+        with pytest.raises(KeyError, match="missing_key"):
+            df[[("missing_key",)]]
+
+    def test_multiindex_dtype_preservation(self):
+        # GH51261
+        columns = MultiIndex.from_tuples([("A", "B")], names=["lvl1", "lvl2"])
+        df = DataFrame(["value"], columns=columns).astype("category")
+        df_no_multiindex = df["A"]
+        assert isinstance(df_no_multiindex["B"].dtype, CategoricalDtype)
+
+        # geopandas 1763 analogue
+        df = DataFrame(
+            [[1, 0], [0, 1]],
+            columns=[
+                ["foo", "foo"],
+                ["location", "location"],
+                ["x", "y"],
+            ],
+        ).assign(bools=Series([True, False], dtype="boolean"))
+        assert isinstance(df["bools"].dtype, BooleanDtype)
+
+    def test_multiindex_from_tuples_with_nan(self):
+        # GH#23578
+        result = MultiIndex.from_tuples([("a", "b", "c"), np.nan, ("d", "", "")])
+        expected = MultiIndex.from_tuples(
+            [("a", "b", "c"), (np.nan, np.nan, np.nan), ("d", "", "")]
+        )
+        tm.assert_index_equal(result, expected)

venv/lib/python3.10/site-packages/pandas/tests/indexing/multiindex/test_partial.py

@@ -0,0 +1,269 @@
+import numpy as np
+import pytest
+
+import pandas.util._test_decorators as td
+
+from pandas import (
+    DataFrame,
+    DatetimeIndex,
+    MultiIndex,
+    date_range,
+)
+import pandas._testing as tm
+
+
+class TestMultiIndexPartial:
+    def test_getitem_partial_int(self):
+        # GH 12416
+        # with single item
+        l1 = [10, 20]
+        l2 = ["a", "b"]
+        df = DataFrame(index=range(2), columns=MultiIndex.from_product([l1, l2]))
+        expected = DataFrame(index=range(2), columns=l2)
+        result = df[20]
+        tm.assert_frame_equal(result, expected)
+
+        # with list
+        expected = DataFrame(
+            index=range(2), columns=MultiIndex.from_product([l1[1:], l2])
+        )
+        result = df[[20]]
+        tm.assert_frame_equal(result, expected)
+
+        # missing item:
+        with pytest.raises(KeyError, match="1"):
+            df[1]
+        with pytest.raises(KeyError, match=r"'\[1\] not in index'"):
+            df[[1]]
+
+    def test_series_slice_partial(self):
+        pass
+
+    def test_xs_partial(
+        self,
+        multiindex_dataframe_random_data,
+        multiindex_year_month_day_dataframe_random_data,
+    ):
+        frame = multiindex_dataframe_random_data
+        ymd = multiindex_year_month_day_dataframe_random_data
+        result = frame.xs("foo")
+        result2 = frame.loc["foo"]
+        expected = frame.T["foo"].T
+        tm.assert_frame_equal(result, expected)
+        tm.assert_frame_equal(result, result2)
+
+        result = ymd.xs((2000, 4))
+        expected = ymd.loc[2000, 4]
+        tm.assert_frame_equal(result, expected)
+
+        # ex from #1796
+        index = MultiIndex(
+            levels=[["foo", "bar"], ["one", "two"], [-1, 1]],
+            codes=[
+                [0, 0, 0, 0, 1, 1, 1, 1],
+                [0, 0, 1, 1, 0, 0, 1, 1],
+                [0, 1, 0, 1, 0, 1, 0, 1],
+            ],
+        )
+        df = DataFrame(
+            np.random.default_rng(2).standard_normal((8, 4)),
+            index=index,
+            columns=list("abcd"),
+        )
+
+        result = df.xs(("foo", "one"))
+        expected = df.loc["foo", "one"]
+        tm.assert_frame_equal(result, expected)
+
+    def test_getitem_partial(self, multiindex_year_month_day_dataframe_random_data):
+        ymd = multiindex_year_month_day_dataframe_random_data
+        ymd = ymd.T
+        result = ymd[2000, 2]
+
+        expected = ymd.reindex(columns=ymd.columns[ymd.columns.codes[1] == 1])
+        expected.columns = expected.columns.droplevel(0).droplevel(0)
+        tm.assert_frame_equal(result, expected)
+
+    def test_fancy_slice_partial(
+        self,
+        multiindex_dataframe_random_data,
+        multiindex_year_month_day_dataframe_random_data,
+    ):
+        frame = multiindex_dataframe_random_data
+        result = frame.loc["bar":"baz"]
+        expected = frame[3:7]
+        tm.assert_frame_equal(result, expected)
+
+        ymd = multiindex_year_month_day_dataframe_random_data
+        result = ymd.loc[(2000, 2):(2000, 4)]
+        lev = ymd.index.codes[1]
+        expected = ymd[(lev >= 1) & (lev <= 3)]
+        tm.assert_frame_equal(result, expected)
+
+    def test_getitem_partial_column_select(self):
+        idx = MultiIndex(
+            codes=[[0, 0, 0], [0, 1, 1], [1, 0, 1]],
+            levels=[["a", "b"], ["x", "y"], ["p", "q"]],
+        )
+        df = DataFrame(np.random.default_rng(2).random((3, 2)), index=idx)
+
+        result = df.loc[("a", "y"), :]
+        expected = df.loc[("a", "y")]
+        tm.assert_frame_equal(result, expected)
+
+        result = df.loc[("a", "y"), [1, 0]]
+        expected = df.loc[("a", "y")][[1, 0]]
+        tm.assert_frame_equal(result, expected)
+
+        with pytest.raises(KeyError, match=r"\('a', 'foo'\)"):
+            df.loc[("a", "foo"), :]
+
+    # TODO(ArrayManager) rewrite test to not use .values
+    # exp.loc[2000, 4].values[:] select multiple columns -> .values is not a view
+    @td.skip_array_manager_invalid_test
+    def test_partial_set(
+        self,
+        multiindex_year_month_day_dataframe_random_data,
+        using_copy_on_write,
+        warn_copy_on_write,
+    ):
+        # GH #397
+        ymd = multiindex_year_month_day_dataframe_random_data
+        df = ymd.copy()
+        exp = ymd.copy()
+        df.loc[2000, 4] = 0
+        exp.iloc[65:85] = 0
+        tm.assert_frame_equal(df, exp)
+
+        if using_copy_on_write:
+            with tm.raises_chained_assignment_error():
+                df["A"].loc[2000, 4] = 1
+            df.loc[(2000, 4), "A"] = 1
+        else:
+            with tm.raises_chained_assignment_error():
+                df["A"].loc[2000, 4] = 1
+        exp.iloc[65:85, 0] = 1
+        tm.assert_frame_equal(df, exp)
+
+        df.loc[2000] = 5
+        exp.iloc[:100] = 5
+        tm.assert_frame_equal(df, exp)
+
+        # this works...for now
+        with tm.raises_chained_assignment_error():
+            df["A"].iloc[14] = 5
+        if using_copy_on_write:
+            assert df["A"].iloc[14] == exp["A"].iloc[14]
+        else:
+            assert df["A"].iloc[14] == 5
+
+    @pytest.mark.parametrize("dtype", [int, float])
+    def test_getitem_intkey_leading_level(
+        self, multiindex_year_month_day_dataframe_random_data, dtype
+    ):
+        # GH#33355 dont fall-back to positional when leading level is int
+        ymd = multiindex_year_month_day_dataframe_random_data
+        levels = ymd.index.levels
+        ymd.index = ymd.index.set_levels([levels[0].astype(dtype)] + levels[1:])
+        ser = ymd["A"]
+        mi = ser.index
+        assert isinstance(mi, MultiIndex)
+        if dtype is int:
+            assert mi.levels[0].dtype == np.dtype(int)
+        else:
+            assert mi.levels[0].dtype == np.float64
+
+        assert 14 not in mi.levels[0]
+        assert not mi.levels[0]._should_fallback_to_positional
+        assert not mi._should_fallback_to_positional
+
+        with pytest.raises(KeyError, match="14"):
+            ser[14]
+
+    # ---------------------------------------------------------------------
+
+    def test_setitem_multiple_partial(self, multiindex_dataframe_random_data):
+        frame = multiindex_dataframe_random_data
+        expected = frame.copy()
+        result = frame.copy()
+        result.loc[["foo", "bar"]] = 0
+        expected.loc["foo"] = 0
+        expected.loc["bar"] = 0
+        tm.assert_frame_equal(result, expected)
+
+        expected = frame.copy()
+        result = frame.copy()
+        result.loc["foo":"bar"] = 0
+        expected.loc["foo"] = 0
+        expected.loc["bar"] = 0
+        tm.assert_frame_equal(result, expected)
+
+        expected = frame["A"].copy()
+        result = frame["A"].copy()
+        result.loc[["foo", "bar"]] = 0
+        expected.loc["foo"] = 0
+        expected.loc["bar"] = 0
+        tm.assert_series_equal(result, expected)
+
+        expected = frame["A"].copy()
+        result = frame["A"].copy()
+        result.loc["foo":"bar"] = 0
+        expected.loc["foo"] = 0
+        expected.loc["bar"] = 0
+        tm.assert_series_equal(result, expected)
+
+    @pytest.mark.parametrize(
+        "indexer, exp_idx, exp_values",
+        [
+            (
+                slice("2019-2", None),
+                DatetimeIndex(["2019-02-01"], dtype="M8[ns]"),
+                [2, 3],
+            ),
+            (
+                slice(None, "2019-2"),
+                date_range("2019", periods=2, freq="MS"),
+                [0, 1, 2, 3],
+            ),
+        ],
+    )
+    def test_partial_getitem_loc_datetime(self, indexer, exp_idx, exp_values):
+        # GH: 25165
+        date_idx = date_range("2019", periods=2, freq="MS")
+        df = DataFrame(
+            list(range(4)),
+            index=MultiIndex.from_product([date_idx, [0, 1]], names=["x", "y"]),
+        )
+        expected = DataFrame(
+            exp_values,
+            index=MultiIndex.from_product([exp_idx, [0, 1]], names=["x", "y"]),
+        )
+        result = df[indexer]
+        tm.assert_frame_equal(result, expected)
+        result = df.loc[indexer]
+        tm.assert_frame_equal(result, expected)
+
+        result = df.loc(axis=0)[indexer]
+        tm.assert_frame_equal(result, expected)
+
+        result = df.loc[indexer, :]
+        tm.assert_frame_equal(result, expected)
+
+        df2 = df.swaplevel(0, 1).sort_index()
+        expected = expected.swaplevel(0, 1).sort_index()
+
+        result = df2.loc[:, indexer, :]
+        tm.assert_frame_equal(result, expected)
+
+
+def test_loc_getitem_partial_both_axis():
+    # gh-12660
+    iterables = [["a", "b"], [2, 1]]
+    columns = MultiIndex.from_product(iterables, names=["col1", "col2"])
+    rows = MultiIndex.from_product(iterables, names=["row1", "row2"])
+    df = DataFrame(
+        np.random.default_rng(2).standard_normal((4, 4)), index=rows, columns=columns
+    )
+    expected = df.iloc[:2, 2:].droplevel("row1").droplevel("col1", axis=1)
+    result = df.loc["a", "b"]
+    tm.assert_frame_equal(result, expected)

venv/lib/python3.10/site-packages/pandas/tests/indexing/multiindex/test_setitem.py

@@ -0,0 +1,589 @@
+import numpy as np
+import pytest
+
+from pandas.errors import SettingWithCopyError
+import pandas.util._test_decorators as td
+
+import pandas as pd
+from pandas import (
+    DataFrame,
+    MultiIndex,
+    Series,
+    date_range,
+    isna,
+    notna,
+)
+import pandas._testing as tm
+
+
+def assert_equal(a, b):
+    assert a == b
+
+
+class TestMultiIndexSetItem:
+    def check(self, target, indexers, value, compare_fn=assert_equal, expected=None):
+        target.loc[indexers] = value
+        result = target.loc[indexers]
+        if expected is None:
+            expected = value
+        compare_fn(result, expected)
+
+    def test_setitem_multiindex(self):
+        # GH#7190
+        cols = ["A", "w", "l", "a", "x", "X", "d", "profit"]
+        index = MultiIndex.from_product(
+            [np.arange(0, 100), np.arange(0, 80)], names=["time", "firm"]
+        )
+        t, n = 0, 2
+
+        df = DataFrame(
+            np.nan,
+            columns=cols,
+            index=index,
+        )
+        self.check(target=df, indexers=((t, n), "X"), value=0)
+
+        df = DataFrame(-999, columns=cols, index=index)
+        self.check(target=df, indexers=((t, n), "X"), value=1)
+
+        df = DataFrame(columns=cols, index=index)
+        self.check(target=df, indexers=((t, n), "X"), value=2)
+
+        # gh-7218: assigning with 0-dim arrays
+        df = DataFrame(-999, columns=cols, index=index)
+        self.check(
+            target=df,
+            indexers=((t, n), "X"),
+            value=np.array(3),
+            expected=3,
+        )
+
+    def test_setitem_multiindex2(self):
+        # GH#5206
+        df = DataFrame(
+            np.arange(25).reshape(5, 5), columns="A,B,C,D,E".split(","), dtype=float
+        )
+        df["F"] = 99
+        row_selection = df["A"] % 2 == 0
+        col_selection = ["B", "C"]
+        df.loc[row_selection, col_selection] = df["F"]
+        output = DataFrame(99.0, index=[0, 2, 4], columns=["B", "C"])
+        tm.assert_frame_equal(df.loc[row_selection, col_selection], output)
+        self.check(
+            target=df,
+            indexers=(row_selection, col_selection),
+            value=df["F"],
+            compare_fn=tm.assert_frame_equal,
+            expected=output,
+        )
+
+    def test_setitem_multiindex3(self):
+        # GH#11372
+        idx = MultiIndex.from_product(
+            [["A", "B", "C"], date_range("2015-01-01", "2015-04-01", freq="MS")]
+        )
+        cols = MultiIndex.from_product(
+            [["foo", "bar"], date_range("2016-01-01", "2016-02-01", freq="MS")]
+        )
+
+        df = DataFrame(
+            np.random.default_rng(2).random((12, 4)), index=idx, columns=cols
+        )
+
+        subidx = MultiIndex.from_arrays(
+            [["A", "A"], date_range("2015-01-01", "2015-02-01", freq="MS")]
+        )
+        subcols = MultiIndex.from_arrays(
+            [["foo", "foo"], date_range("2016-01-01", "2016-02-01", freq="MS")]
+        )
+
+        vals = DataFrame(
+            np.random.default_rng(2).random((2, 2)), index=subidx, columns=subcols
+        )
+        self.check(
+            target=df,
+            indexers=(subidx, subcols),
+            value=vals,
+            compare_fn=tm.assert_frame_equal,
+        )
+        # set all columns
+        vals = DataFrame(
+            np.random.default_rng(2).random((2, 4)), index=subidx, columns=cols
+        )
+        self.check(
+            target=df,
+            indexers=(subidx, slice(None, None, None)),
+            value=vals,
+            compare_fn=tm.assert_frame_equal,
+        )
+        # identity
+        copy = df.copy()
+        self.check(
+            target=df,
+            indexers=(df.index, df.columns),
+            value=df,
+            compare_fn=tm.assert_frame_equal,
+            expected=copy,
+        )
+
+    # TODO(ArrayManager) df.loc["bar"] *= 2 doesn't raise an error but results in
+    # all NaNs -> doesn't work in the "split" path (also for BlockManager actually)
+    @td.skip_array_manager_not_yet_implemented
+    def test_multiindex_setitem(self):
+        # GH 3738
+        # setting with a multi-index right hand side
+        arrays = [
+            np.array(["bar", "bar", "baz", "qux", "qux", "bar"]),
+            np.array(["one", "two", "one", "one", "two", "one"]),
+            np.arange(0, 6, 1),
+        ]
+
+        df_orig = DataFrame(
+            np.random.default_rng(2).standard_normal((6, 3)),
+            index=arrays,
+            columns=["A", "B", "C"],
+        ).sort_index()
+
+        expected = df_orig.loc[["bar"]] * 2
+        df = df_orig.copy()
+        df.loc[["bar"]] *= 2
+        tm.assert_frame_equal(df.loc[["bar"]], expected)
+
+        # raise because these have differing levels
+        msg = "cannot align on a multi-index with out specifying the join levels"
+        with pytest.raises(TypeError, match=msg):
+            df.loc["bar"] *= 2
+
+    def test_multiindex_setitem2(self):
+        # from SO
+        # https://stackoverflow.com/questions/24572040/pandas-access-the-level-of-multiindex-for-inplace-operation
+        df_orig = DataFrame.from_dict(
+            {
+                "price": {
+                    ("DE", "Coal", "Stock"): 2,
+                    ("DE", "Gas", "Stock"): 4,
+                    ("DE", "Elec", "Demand"): 1,
+                    ("FR", "Gas", "Stock"): 5,
+                    ("FR", "Solar", "SupIm"): 0,
+                    ("FR", "Wind", "SupIm"): 0,
+                }
+            }
+        )
+        df_orig.index = MultiIndex.from_tuples(
+            df_orig.index, names=["Sit", "Com", "Type"]
+        )
+
+        expected = df_orig.copy()
+        expected.iloc[[0, 1, 3]] *= 2
+
+        idx = pd.IndexSlice
+        df = df_orig.copy()
+        df.loc[idx[:, :, "Stock"], :] *= 2
+        tm.assert_frame_equal(df, expected)
+
+        df = df_orig.copy()
+        df.loc[idx[:, :, "Stock"], "price"] *= 2
+        tm.assert_frame_equal(df, expected)
+
+    def test_multiindex_assignment(self):
+        # GH3777 part 2
+
+        # mixed dtype
+        df = DataFrame(
+            np.random.default_rng(2).integers(5, 10, size=9).reshape(3, 3),
+            columns=list("abc"),
+            index=[[4, 4, 8], [8, 10, 12]],
+        )
+        df["d"] = np.nan
+        arr = np.array([0.0, 1.0])
+
+        df.loc[4, "d"] = arr
+        tm.assert_series_equal(df.loc[4, "d"], Series(arr, index=[8, 10], name="d"))
+
+    def test_multiindex_assignment_single_dtype(
+        self, using_copy_on_write, warn_copy_on_write
+    ):
+        # GH3777 part 2b
+        # single dtype
+        arr = np.array([0.0, 1.0])
+
+        df = DataFrame(
+            np.random.default_rng(2).integers(5, 10, size=9).reshape(3, 3),
+            columns=list("abc"),
+            index=[[4, 4, 8], [8, 10, 12]],
+            dtype=np.int64,
+        )
+        view = df["c"].iloc[:2].values
+
+        # arr can be losslessly cast to int, so this setitem is inplace
+        # INFO(CoW-warn) this does not warn because we directly took .values
+        # above, so no reference to a pandas object is alive for `view`
+        df.loc[4, "c"] = arr
+        exp = Series(arr, index=[8, 10], name="c", dtype="int64")
+        result = df.loc[4, "c"]
+        tm.assert_series_equal(result, exp)
+
+        # extra check for inplace-ness
+        if not using_copy_on_write:
+            tm.assert_numpy_array_equal(view, exp.values)
+
+        # arr + 0.5 cannot be cast losslessly to int, so we upcast
+        with tm.assert_produces_warning(
+            FutureWarning, match="item of incompatible dtype"
+        ):
+            df.loc[4, "c"] = arr + 0.5
+        result = df.loc[4, "c"]
+        exp = exp + 0.5
+        tm.assert_series_equal(result, exp)
+
+        # scalar ok
+        with tm.assert_cow_warning(warn_copy_on_write):
+            df.loc[4, "c"] = 10
+        exp = Series(10, index=[8, 10], name="c", dtype="float64")
+        tm.assert_series_equal(df.loc[4, "c"], exp)
+
+        # invalid assignments
+        msg = "Must have equal len keys and value when setting with an iterable"
+        with pytest.raises(ValueError, match=msg):
+            df.loc[4, "c"] = [0, 1, 2, 3]
+
+        with pytest.raises(ValueError, match=msg):
+            df.loc[4, "c"] = [0]
+
+        # But with a length-1 listlike column indexer this behaves like
+        #  `df.loc[4, "c"] = 0
+        with tm.assert_cow_warning(warn_copy_on_write):
+            df.loc[4, ["c"]] = [0]
+        assert (df.loc[4, "c"] == 0).all()
+
+    def test_groupby_example(self):
+        # groupby example
+        NUM_ROWS = 100
+        NUM_COLS = 10
+        col_names = ["A" + num for num in map(str, np.arange(NUM_COLS).tolist())]
+        index_cols = col_names[:5]
+
+        df = DataFrame(
+            np.random.default_rng(2).integers(5, size=(NUM_ROWS, NUM_COLS)),
+            dtype=np.int64,
+            columns=col_names,
+        )
+        df = df.set_index(index_cols).sort_index()
+        grp = df.groupby(level=index_cols[:4])
+        df["new_col"] = np.nan
+
+        # we are actually operating on a copy here
+        # but in this case, that's ok
+        for name, df2 in grp:
+            new_vals = np.arange(df2.shape[0])
+            df.loc[name, "new_col"] = new_vals
+
+    def test_series_setitem(
+        self, multiindex_year_month_day_dataframe_random_data, warn_copy_on_write
+    ):
+        ymd = multiindex_year_month_day_dataframe_random_data
+        s = ymd["A"]
+
+        with tm.assert_cow_warning(warn_copy_on_write):
+            s[2000, 3] = np.nan
+        assert isna(s.values[42:65]).all()
+        assert notna(s.values[:42]).all()
+        assert notna(s.values[65:]).all()
+
+        with tm.assert_cow_warning(warn_copy_on_write):
+            s[2000, 3, 10] = np.nan
+        assert isna(s.iloc[49])
+
+        with pytest.raises(KeyError, match="49"):
+            # GH#33355 dont fall-back to positional when leading level is int
+            s[49]
+
+    def test_frame_getitem_setitem_boolean(self, multiindex_dataframe_random_data):
+        frame = multiindex_dataframe_random_data
+        df = frame.T.copy()
+        values = df.values.copy()
+
+        result = df[df > 0]
+        expected = df.where(df > 0)
+        tm.assert_frame_equal(result, expected)
+
+        df[df > 0] = 5
+        values[values > 0] = 5
+        tm.assert_almost_equal(df.values, values)
+
+        df[df == 5] = 0
+        values[values == 5] = 0
+        tm.assert_almost_equal(df.values, values)
+
+        # a df that needs alignment first
+        df[df[:-1] < 0] = 2
+        np.putmask(values[:-1], values[:-1] < 0, 2)
+        tm.assert_almost_equal(df.values, values)
+
+        with pytest.raises(TypeError, match="boolean values only"):
+            df[df * 0] = 2
+
+    def test_frame_getitem_setitem_multislice(self):
+        levels = [["t1", "t2"], ["a", "b", "c"]]
+        codes = [[0, 0, 0, 1, 1], [0, 1, 2, 0, 1]]
+        midx = MultiIndex(codes=codes, levels=levels, names=[None, "id"])
+        df = DataFrame({"value": [1, 2, 3, 7, 8]}, index=midx)
+
+        result = df.loc[:, "value"]
+        tm.assert_series_equal(df["value"], result)
+
+        result = df.loc[df.index[1:3], "value"]
+        tm.assert_series_equal(df["value"][1:3], result)
+
+        result = df.loc[:, :]
+        tm.assert_frame_equal(df, result)
+
+        result = df
+        df.loc[:, "value"] = 10
+        result["value"] = 10
+        tm.assert_frame_equal(df, result)
+
+        df.loc[:, :] = 10
+        tm.assert_frame_equal(df, result)
+
+    def test_frame_setitem_multi_column(self):
+        df = DataFrame(
+            np.random.default_rng(2).standard_normal((10, 4)),
+            columns=[["a", "a", "b", "b"], [0, 1, 0, 1]],
+        )
+
+        cp = df.copy()
+        cp["a"] = cp["b"]
+        tm.assert_frame_equal(cp["a"], cp["b"])
+
+        # set with ndarray
+        cp = df.copy()
+        cp["a"] = cp["b"].values
+        tm.assert_frame_equal(cp["a"], cp["b"])
+
+    def test_frame_setitem_multi_column2(self):
+        # ---------------------------------------
+        # GH#1803
+        columns = MultiIndex.from_tuples([("A", "1"), ("A", "2"), ("B", "1")])
+        df = DataFrame(index=[1, 3, 5], columns=columns)
+
+        # Works, but adds a column instead of updating the two existing ones
+        df["A"] = 0.0  # Doesn't work
+        assert (df["A"].values == 0).all()
+
+        # it broadcasts
+        df["B", "1"] = [1, 2, 3]
+        df["A"] = df["B", "1"]
+
+        sliced_a1 = df["A", "1"]
+        sliced_a2 = df["A", "2"]
+        sliced_b1 = df["B", "1"]
+        tm.assert_series_equal(sliced_a1, sliced_b1, check_names=False)
+        tm.assert_series_equal(sliced_a2, sliced_b1, check_names=False)
+        assert sliced_a1.name == ("A", "1")
+        assert sliced_a2.name == ("A", "2")
+        assert sliced_b1.name == ("B", "1")
+
+    def test_loc_getitem_tuple_plus_columns(
+        self, multiindex_year_month_day_dataframe_random_data
+    ):
+        # GH #1013
+        ymd = multiindex_year_month_day_dataframe_random_data
+        df = ymd[:5]
+
+        result = df.loc[(2000, 1, 6), ["A", "B", "C"]]
+        expected = df.loc[2000, 1, 6][["A", "B", "C"]]
+        tm.assert_series_equal(result, expected)
+
+    @pytest.mark.filterwarnings("ignore:Setting a value on a view:FutureWarning")
+    def test_loc_getitem_setitem_slice_integers(self, frame_or_series):
+        index = MultiIndex(
+            levels=[[0, 1, 2], [0, 2]], codes=[[0, 0, 1, 1, 2, 2], [0, 1, 0, 1, 0, 1]]
+        )
+
+        obj = DataFrame(
+            np.random.default_rng(2).standard_normal((len(index), 4)),
+            index=index,
+            columns=["a", "b", "c", "d"],
+        )
+        obj = tm.get_obj(obj, frame_or_series)
+
+        res = obj.loc[1:2]
+        exp = obj.reindex(obj.index[2:])
+        tm.assert_equal(res, exp)
+
+        obj.loc[1:2] = 7
+        assert (obj.loc[1:2] == 7).values.all()
+
+    def test_setitem_change_dtype(self, multiindex_dataframe_random_data):
+        frame = multiindex_dataframe_random_data
+        dft = frame.T
+        s = dft["foo", "two"]
+        dft["foo", "two"] = s > s.median()
+        tm.assert_series_equal(dft["foo", "two"], s > s.median())
+        # assert isinstance(dft._data.blocks[1].items, MultiIndex)
+
+        reindexed = dft.reindex(columns=[("foo", "two")])
+        tm.assert_series_equal(reindexed["foo", "two"], s > s.median())
+
+    def test_set_column_scalar_with_loc(
+        self, multiindex_dataframe_random_data, using_copy_on_write, warn_copy_on_write
+    ):
+        frame = multiindex_dataframe_random_data
+        subset = frame.index[[1, 4, 5]]
+
+        frame.loc[subset] = 99
+        assert (frame.loc[subset].values == 99).all()
+
+        frame_original = frame.copy()
+        col = frame["B"]
+        with tm.assert_cow_warning(warn_copy_on_write):
+            col[subset] = 97
+        if using_copy_on_write:
+            # chained setitem doesn't work with CoW
+            tm.assert_frame_equal(frame, frame_original)
+        else:
+            assert (frame.loc[subset, "B"] == 97).all()
+
+    def test_nonunique_assignment_1750(self):
+        df = DataFrame(
+            [[1, 1, "x", "X"], [1, 1, "y", "Y"], [1, 2, "z", "Z"]], columns=list("ABCD")
+        )
+
+        df = df.set_index(["A", "B"])
+        mi = MultiIndex.from_tuples([(1, 1)])
+
+        df.loc[mi, "C"] = "_"
+
+        assert (df.xs((1, 1))["C"] == "_").all()
+
+    def test_astype_assignment_with_dups(self):
+        # GH 4686
+        # assignment with dups that has a dtype change
+        cols = MultiIndex.from_tuples([("A", "1"), ("B", "1"), ("A", "2")])
+        df = DataFrame(np.arange(3).reshape((1, 3)), columns=cols, dtype=object)
+        index = df.index.copy()
+
+        df["A"] = df["A"].astype(np.float64)
+        tm.assert_index_equal(df.index, index)
+
+    def test_setitem_nonmonotonic(self):
+        # https://github.com/pandas-dev/pandas/issues/31449
+        index = MultiIndex.from_tuples(
+            [("a", "c"), ("b", "x"), ("a", "d")], names=["l1", "l2"]
+        )
+        df = DataFrame(data=[0, 1, 2], index=index, columns=["e"])
+        df.loc["a", "e"] = np.arange(99, 101, dtype="int64")
+        expected = DataFrame({"e": [99, 1, 100]}, index=index)
+        tm.assert_frame_equal(df, expected)
+
+
+class TestSetitemWithExpansionMultiIndex:
+    def test_setitem_new_column_mixed_depth(self):
+        arrays = [
+            ["a", "top", "top", "routine1", "routine1", "routine2"],
+            ["", "OD", "OD", "result1", "result2", "result1"],
+            ["", "wx", "wy", "", "", ""],
+        ]
+
+        tuples = sorted(zip(*arrays))
+        index = MultiIndex.from_tuples(tuples)
+        df = DataFrame(np.random.default_rng(2).standard_normal((4, 6)), columns=index)
+
+        result = df.copy()
+        expected = df.copy()
+        result["b"] = [1, 2, 3, 4]
+        expected["b", "", ""] = [1, 2, 3, 4]
+        tm.assert_frame_equal(result, expected)
+
+    def test_setitem_new_column_all_na(self):
+        # GH#1534
+        mix = MultiIndex.from_tuples([("1a", "2a"), ("1a", "2b"), ("1a", "2c")])
+        df = DataFrame([[1, 2], [3, 4], [5, 6]], index=mix)
+        s = Series({(1, 1): 1, (1, 2): 2})
+        df["new"] = s
+        assert df["new"].isna().all()
+
+    def test_setitem_enlargement_keep_index_names(self):
+        # GH#53053
+        mi = MultiIndex.from_tuples([(1, 2, 3)], names=["i1", "i2", "i3"])
+        df = DataFrame(data=[[10, 20, 30]], index=mi, columns=["A", "B", "C"])
+        df.loc[(0, 0, 0)] = df.loc[(1, 2, 3)]
+        mi_expected = MultiIndex.from_tuples(
+            [(1, 2, 3), (0, 0, 0)], names=["i1", "i2", "i3"]
+        )
+        expected = DataFrame(
+            data=[[10, 20, 30], [10, 20, 30]],
+            index=mi_expected,
+            columns=["A", "B", "C"],
+        )
+        tm.assert_frame_equal(df, expected)
+
+
+@td.skip_array_manager_invalid_test  # df["foo"] select multiple columns -> .values
+# is not a view
+def test_frame_setitem_view_direct(
+    multiindex_dataframe_random_data, using_copy_on_write
+):
+    # this works because we are modifying the underlying array
+    # really a no-no
+    df = multiindex_dataframe_random_data.T
+    if using_copy_on_write:
+        with pytest.raises(ValueError, match="read-only"):
+            df["foo"].values[:] = 0
+        assert (df["foo"].values != 0).all()
+    else:
+        df["foo"].values[:] = 0
+        assert (df["foo"].values == 0).all()
+
+
+def test_frame_setitem_copy_raises(
+    multiindex_dataframe_random_data, using_copy_on_write, warn_copy_on_write
+):
+    # will raise/warn as its chained assignment
+    df = multiindex_dataframe_random_data.T
+    if using_copy_on_write or warn_copy_on_write:
+        with tm.raises_chained_assignment_error():
+            df["foo"]["one"] = 2
+    else:
+        msg = "A value is trying to be set on a copy of a slice from a DataFrame"
+        with pytest.raises(SettingWithCopyError, match=msg):
+            with tm.raises_chained_assignment_error():
+                df["foo"]["one"] = 2
+
+
+def test_frame_setitem_copy_no_write(
+    multiindex_dataframe_random_data, using_copy_on_write, warn_copy_on_write
+):
+    frame = multiindex_dataframe_random_data.T
+    expected = frame
+    df = frame.copy()
+    if using_copy_on_write or warn_copy_on_write:
+        with tm.raises_chained_assignment_error():
+            df["foo"]["one"] = 2
+    else:
+        msg = "A value is trying to be set on a copy of a slice from a DataFrame"
+        with pytest.raises(SettingWithCopyError, match=msg):
+            with tm.raises_chained_assignment_error():
+                df["foo"]["one"] = 2
+
+    result = df
+    tm.assert_frame_equal(result, expected)
+
+
+def test_frame_setitem_partial_multiindex():
+    # GH 54875
+    df = DataFrame(
+        {
+            "a": [1, 2, 3],
+            "b": [3, 4, 5],
+            "c": 6,
+            "d": 7,
+        }
+    ).set_index(["a", "b", "c"])
+    ser = Series(8, index=df.index.droplevel("c"))
+    result = df.copy()
+    result["d"] = ser
+    expected = df.copy()
+    expected["d"] = 8
+    tm.assert_frame_equal(result, expected)

venv/lib/python3.10/site-packages/pandas/tests/indexing/multiindex/test_slice.py

@@ -0,0 +1,796 @@
+from datetime import (
+    datetime,
+    timedelta,
+)
+
+import numpy as np
+import pytest
+
+from pandas.errors import UnsortedIndexError
+
+import pandas as pd
+from pandas import (
+    DataFrame,
+    Index,
+    MultiIndex,
+    Series,
+    Timestamp,
+)
+import pandas._testing as tm
+from pandas.tests.indexing.common import _mklbl
+
+
+class TestMultiIndexSlicers:
+    def test_per_axis_per_level_getitem(self):
+        # GH6134
+        # example test case
+        ix = MultiIndex.from_product(
+            [_mklbl("A", 5), _mklbl("B", 7), _mklbl("C", 4), _mklbl("D", 2)]
+        )
+        df = DataFrame(np.arange(len(ix.to_numpy())), index=ix)
+
+        result = df.loc[(slice("A1", "A3"), slice(None), ["C1", "C3"]), :]
+        expected = df.loc[
+            [
+                (
+                    a,
+                    b,
+                    c,
+                    d,
+                )
+                for a, b, c, d in df.index.values
+                if a in ("A1", "A2", "A3") and c in ("C1", "C3")
+            ]
+        ]
+        tm.assert_frame_equal(result, expected)
+
+        expected = df.loc[
+            [
+                (
+                    a,
+                    b,
+                    c,
+                    d,
+                )
+                for a, b, c, d in df.index.values
+                if a in ("A1", "A2", "A3") and c in ("C1", "C2", "C3")
+            ]
+        ]
+        result = df.loc[(slice("A1", "A3"), slice(None), slice("C1", "C3")), :]
+        tm.assert_frame_equal(result, expected)
+
+        # test multi-index slicing with per axis and per index controls
+        index = MultiIndex.from_tuples(
+            [("A", 1), ("A", 2), ("A", 3), ("B", 1)], names=["one", "two"]
+        )
+        columns = MultiIndex.from_tuples(
+            [("a", "foo"), ("a", "bar"), ("b", "foo"), ("b", "bah")],
+            names=["lvl0", "lvl1"],
+        )
+
+        df = DataFrame(
+            np.arange(16, dtype="int64").reshape(4, 4), index=index, columns=columns
+        )
+        df = df.sort_index(axis=0).sort_index(axis=1)
+
+        # identity
+        result = df.loc[(slice(None), slice(None)), :]
+        tm.assert_frame_equal(result, df)
+        result = df.loc[(slice(None), slice(None)), (slice(None), slice(None))]
+        tm.assert_frame_equal(result, df)
+        result = df.loc[:, (slice(None), slice(None))]
+        tm.assert_frame_equal(result, df)
+
+        # index
+        result = df.loc[(slice(None), [1]), :]
+        expected = df.iloc[[0, 3]]
+        tm.assert_frame_equal(result, expected)
+
+        result = df.loc[(slice(None), 1), :]
+        expected = df.iloc[[0, 3]]
+        tm.assert_frame_equal(result, expected)
+
+        # columns
+        result = df.loc[:, (slice(None), ["foo"])]
+        expected = df.iloc[:, [1, 3]]
+        tm.assert_frame_equal(result, expected)
+
+        # both
+        result = df.loc[(slice(None), 1), (slice(None), ["foo"])]
+        expected = df.iloc[[0, 3], [1, 3]]
+        tm.assert_frame_equal(result, expected)
+
+        result = df.loc["A", "a"]
+        expected = DataFrame(
+            {"bar": [1, 5, 9], "foo": [0, 4, 8]},
+            index=Index([1, 2, 3], name="two"),
+            columns=Index(["bar", "foo"], name="lvl1"),
+        )
+        tm.assert_frame_equal(result, expected)
+
+        result = df.loc[(slice(None), [1, 2]), :]
+        expected = df.iloc[[0, 1, 3]]
+        tm.assert_frame_equal(result, expected)
+
+        # multi-level series
+        s = Series(np.arange(len(ix.to_numpy())), index=ix)
+        result = s.loc["A1":"A3", :, ["C1", "C3"]]
+        expected = s.loc[
+            [
+                (
+                    a,
+                    b,
+                    c,
+                    d,
+                )
+                for a, b, c, d in s.index.values
+                if a in ("A1", "A2", "A3") and c in ("C1", "C3")
+            ]
+        ]
+        tm.assert_series_equal(result, expected)
+
+        # boolean indexers
+        result = df.loc[(slice(None), df.loc[:, ("a", "bar")] > 5), :]
+        expected = df.iloc[[2, 3]]
+        tm.assert_frame_equal(result, expected)
+
+        msg = (
+            "cannot index with a boolean indexer "
+            "that is not the same length as the index"
+        )
+        with pytest.raises(ValueError, match=msg):
+            df.loc[(slice(None), np.array([True, False])), :]
+
+        with pytest.raises(KeyError, match=r"\[1\] not in index"):
+            # slice(None) is on the index, [1] is on the columns, but 1 is
+            #  not in the columns, so we raise
+            #  This used to treat [1] as positional GH#16396
+            df.loc[slice(None), [1]]
+
+        # not lexsorted
+        assert df.index._lexsort_depth == 2
+        df = df.sort_index(level=1, axis=0)
+        assert df.index._lexsort_depth == 0
+
+        msg = (
+            "MultiIndex slicing requires the index to be "
+            r"lexsorted: slicing on levels \[1\], lexsort depth 0"
+        )
+        with pytest.raises(UnsortedIndexError, match=msg):
+            df.loc[(slice(None), slice("bar")), :]
+
+        # GH 16734: not sorted, but no real slicing
+        result = df.loc[(slice(None), df.loc[:, ("a", "bar")] > 5), :]
+        tm.assert_frame_equal(result, df.iloc[[1, 3], :])
+
+    def test_multiindex_slicers_non_unique(self):
+        # GH 7106
+        # non-unique mi index support
+        df = (
+            DataFrame(
+                {
+                    "A": ["foo", "foo", "foo", "foo"],
+                    "B": ["a", "a", "a", "a"],
+                    "C": [1, 2, 1, 3],
+                    "D": [1, 2, 3, 4],
+                }
+            )
+            .set_index(["A", "B", "C"])
+            .sort_index()
+        )
+        assert not df.index.is_unique
+        expected = (
+            DataFrame({"A": ["foo", "foo"], "B": ["a", "a"], "C": [1, 1], "D": [1, 3]})
+            .set_index(["A", "B", "C"])
+            .sort_index()
+        )
+        result = df.loc[(slice(None), slice(None), 1), :]
+        tm.assert_frame_equal(result, expected)
+
+        # this is equivalent of an xs expression
+        result = df.xs(1, level=2, drop_level=False)
+        tm.assert_frame_equal(result, expected)
+
+        df = (
+            DataFrame(
+                {
+                    "A": ["foo", "foo", "foo", "foo"],
+                    "B": ["a", "a", "a", "a"],
+                    "C": [1, 2, 1, 2],
+                    "D": [1, 2, 3, 4],
+                }
+            )
+            .set_index(["A", "B", "C"])
+            .sort_index()
+        )
+        assert not df.index.is_unique
+        expected = (
+            DataFrame({"A": ["foo", "foo"], "B": ["a", "a"], "C": [1, 1], "D": [1, 3]})
+            .set_index(["A", "B", "C"])
+            .sort_index()
+        )
+        result = df.loc[(slice(None), slice(None), 1), :]
+        assert not result.index.is_unique
+        tm.assert_frame_equal(result, expected)
+
+        # GH12896
+        # numpy-implementation dependent bug
+        ints = [
+            1,
+            2,
+            3,
+            4,
+            5,
+            6,
+            7,
+            8,
+            9,
+            10,
+            11,
+            12,
+            12,
+            13,
+            14,
+            14,
+            16,
+            17,
+            18,
+            19,
+            200000,
+            200000,
+        ]
+        n = len(ints)
+        idx = MultiIndex.from_arrays([["a"] * n, ints])
+        result = Series([1] * n, index=idx)
+        result = result.sort_index()
+        result = result.loc[(slice(None), slice(100000))]
+        expected = Series([1] * (n - 2), index=idx[:-2]).sort_index()
+        tm.assert_series_equal(result, expected)
+
+    def test_multiindex_slicers_datetimelike(self):
+        # GH 7429
+        # buggy/inconsistent behavior when slicing with datetime-like
+        dates = [datetime(2012, 1, 1, 12, 12, 12) + timedelta(days=i) for i in range(6)]
+        freq = [1, 2]
+        index = MultiIndex.from_product([dates, freq], names=["date", "frequency"])
+
+        df = DataFrame(
+            np.arange(6 * 2 * 4, dtype="int64").reshape(-1, 4),
+            index=index,
+            columns=list("ABCD"),
+        )
+
+        # multi-axis slicing
+        idx = pd.IndexSlice
+        expected = df.iloc[[0, 2, 4], [0, 1]]
+        result = df.loc[
+            (
+                slice(
+                    Timestamp("2012-01-01 12:12:12"), Timestamp("2012-01-03 12:12:12")
+                ),
+                slice(1, 1),
+            ),
+            slice("A", "B"),
+        ]
+        tm.assert_frame_equal(result, expected)
+
+        result = df.loc[
+            (
+                idx[
+                    Timestamp("2012-01-01 12:12:12") : Timestamp("2012-01-03 12:12:12")
+                ],
+                idx[1:1],
+            ),
+            slice("A", "B"),
+        ]
+        tm.assert_frame_equal(result, expected)
+
+        result = df.loc[
+            (
+                slice(
+                    Timestamp("2012-01-01 12:12:12"), Timestamp("2012-01-03 12:12:12")
+                ),
+                1,
+            ),
+            slice("A", "B"),
+        ]
+        tm.assert_frame_equal(result, expected)
+
+        # with strings
+        result = df.loc[
+            (slice("2012-01-01 12:12:12", "2012-01-03 12:12:12"), slice(1, 1)),
+            slice("A", "B"),
+        ]
+        tm.assert_frame_equal(result, expected)
+
+        result = df.loc[
+            (idx["2012-01-01 12:12:12":"2012-01-03 12:12:12"], 1), idx["A", "B"]
+        ]
+        tm.assert_frame_equal(result, expected)
+
+    def test_multiindex_slicers_edges(self):
+        # GH 8132
+        # various edge cases
+        df = DataFrame(
+            {
+                "A": ["A0"] * 5 + ["A1"] * 5 + ["A2"] * 5,
+                "B": ["B0", "B0", "B1", "B1", "B2"] * 3,
+                "DATE": [
+                    "2013-06-11",
+                    "2013-07-02",
+                    "2013-07-09",
+                    "2013-07-30",
+                    "2013-08-06",
+                    "2013-06-11",
+                    "2013-07-02",
+                    "2013-07-09",
+                    "2013-07-30",
+                    "2013-08-06",
+                    "2013-09-03",
+                    "2013-10-01",
+                    "2013-07-09",
+                    "2013-08-06",
+                    "2013-09-03",
+                ],
+                "VALUES": [22, 35, 14, 9, 4, 40, 18, 4, 2, 5, 1, 2, 3, 4, 2],
+            }
+        )
+
+        df["DATE"] = pd.to_datetime(df["DATE"])
+        df1 = df.set_index(["A", "B", "DATE"])
+        df1 = df1.sort_index()
+
+        # A1 - Get all values under "A0" and "A1"
+        result = df1.loc[(slice("A1")), :]
+        expected = df1.iloc[0:10]
+        tm.assert_frame_equal(result, expected)
+
+        # A2 - Get all values from the start to "A2"
+        result = df1.loc[(slice("A2")), :]
+        expected = df1
+        tm.assert_frame_equal(result, expected)
+
+        # A3 - Get all values under "B1" or "B2"
+        result = df1.loc[(slice(None), slice("B1", "B2")), :]
+        expected = df1.iloc[[2, 3, 4, 7, 8, 9, 12, 13, 14]]
+        tm.assert_frame_equal(result, expected)
+
+        # A4 - Get all values between 2013-07-02 and 2013-07-09
+        result = df1.loc[(slice(None), slice(None), slice("20130702", "20130709")), :]
+        expected = df1.iloc[[1, 2, 6, 7, 12]]
+        tm.assert_frame_equal(result, expected)
+
+        # B1 - Get all values in B0 that are also under A0, A1 and A2
+        result = df1.loc[(slice("A2"), slice("B0")), :]
+        expected = df1.iloc[[0, 1, 5, 6, 10, 11]]
+        tm.assert_frame_equal(result, expected)
+
+        # B2 - Get all values in B0, B1 and B2 (similar to what #2 is doing for
+        # the As)
+        result = df1.loc[(slice(None), slice("B2")), :]
+        expected = df1
+        tm.assert_frame_equal(result, expected)
+
+        # B3 - Get all values from B1 to B2 and up to 2013-08-06
+        result = df1.loc[(slice(None), slice("B1", "B2"), slice("2013-08-06")), :]
+        expected = df1.iloc[[2, 3, 4, 7, 8, 9, 12, 13]]
+        tm.assert_frame_equal(result, expected)
+
+        # B4 - Same as A4 but the start of the date slice is not a key.
+        #      shows indexing on a partial selection slice
+        result = df1.loc[(slice(None), slice(None), slice("20130701", "20130709")), :]
+        expected = df1.iloc[[1, 2, 6, 7, 12]]
+        tm.assert_frame_equal(result, expected)
+
+    def test_per_axis_per_level_doc_examples(self):
+        # test index maker
+        idx = pd.IndexSlice
+
+        # from indexing.rst / advanced
+        index = MultiIndex.from_product(
+            [_mklbl("A", 4), _mklbl("B", 2), _mklbl("C", 4), _mklbl("D", 2)]
+        )
+        columns = MultiIndex.from_tuples(
+            [("a", "foo"), ("a", "bar"), ("b", "foo"), ("b", "bah")],
+            names=["lvl0", "lvl1"],
+        )
+        df = DataFrame(
+            np.arange(len(index) * len(columns), dtype="int64").reshape(
+                (len(index), len(columns))
+            ),
+            index=index,
+            columns=columns,
+        )
+        result = df.loc[(slice("A1", "A3"), slice(None), ["C1", "C3"]), :]
+        expected = df.loc[
+            [
+                (
+                    a,
+                    b,
+                    c,
+                    d,
+                )
+                for a, b, c, d in df.index.values
+                if a in ("A1", "A2", "A3") and c in ("C1", "C3")
+            ]
+        ]
+        tm.assert_frame_equal(result, expected)
+        result = df.loc[idx["A1":"A3", :, ["C1", "C3"]], :]
+        tm.assert_frame_equal(result, expected)
+
+        result = df.loc[(slice(None), slice(None), ["C1", "C3"]), :]
+        expected = df.loc[
+            [
+                (
+                    a,
+                    b,
+                    c,
+                    d,
+                )
+                for a, b, c, d in df.index.values
+                if c in ("C1", "C3")
+            ]
+        ]
+        tm.assert_frame_equal(result, expected)
+        result = df.loc[idx[:, :, ["C1", "C3"]], :]
+        tm.assert_frame_equal(result, expected)
+
+        # not sorted
+        msg = (
+            "MultiIndex slicing requires the index to be lexsorted: "
+            r"slicing on levels \[1\], lexsort depth 1"
+        )
+        with pytest.raises(UnsortedIndexError, match=msg):
+            df.loc["A1", ("a", slice("foo"))]
+
+        # GH 16734: not sorted, but no real slicing
+        tm.assert_frame_equal(
+            df.loc["A1", (slice(None), "foo")], df.loc["A1"].iloc[:, [0, 2]]
+        )
+
+        df = df.sort_index(axis=1)
+
+        # slicing
+        df.loc["A1", (slice(None), "foo")]
+        df.loc[(slice(None), slice(None), ["C1", "C3"]), (slice(None), "foo")]
+
+        # setitem
+        df.loc(axis=0)[:, :, ["C1", "C3"]] = -10
+
+    def test_loc_axis_arguments(self):
+        index = MultiIndex.from_product(
+            [_mklbl("A", 4), _mklbl("B", 2), _mklbl("C", 4), _mklbl("D", 2)]
+        )
+        columns = MultiIndex.from_tuples(
+            [("a", "foo"), ("a", "bar"), ("b", "foo"), ("b", "bah")],
+            names=["lvl0", "lvl1"],
+        )
+        df = (
+            DataFrame(
+                np.arange(len(index) * len(columns), dtype="int64").reshape(
+                    (len(index), len(columns))
+                ),
+                index=index,
+                columns=columns,
+            )
+            .sort_index()
+            .sort_index(axis=1)
+        )
+
+        # axis 0
+        result = df.loc(axis=0)["A1":"A3", :, ["C1", "C3"]]
+        expected = df.loc[
+            [
+                (
+                    a,
+                    b,
+                    c,
+                    d,
+                )
+                for a, b, c, d in df.index.values
+                if a in ("A1", "A2", "A3") and c in ("C1", "C3")
+            ]
+        ]
+        tm.assert_frame_equal(result, expected)
+
+        result = df.loc(axis="index")[:, :, ["C1", "C3"]]
+        expected = df.loc[
+            [
+                (
+                    a,
+                    b,
+                    c,
+                    d,
+                )
+                for a, b, c, d in df.index.values
+                if c in ("C1", "C3")
+            ]
+        ]
+        tm.assert_frame_equal(result, expected)
+
+        # axis 1
+        result = df.loc(axis=1)[:, "foo"]
+        expected = df.loc[:, (slice(None), "foo")]
+        tm.assert_frame_equal(result, expected)
+
+        result = df.loc(axis="columns")[:, "foo"]
+        expected = df.loc[:, (slice(None), "foo")]
+        tm.assert_frame_equal(result, expected)
+
+        # invalid axis
+        for i in [-1, 2, "foo"]:
+            msg = f"No axis named {i} for object type DataFrame"
+            with pytest.raises(ValueError, match=msg):
+                df.loc(axis=i)[:, :, ["C1", "C3"]]
+
+    def test_loc_axis_single_level_multi_col_indexing_multiindex_col_df(self):
+        # GH29519
+        df = DataFrame(
+            np.arange(27).reshape(3, 9),
+            columns=MultiIndex.from_product([["a1", "a2", "a3"], ["b1", "b2", "b3"]]),
+        )
+        result = df.loc(axis=1)["a1":"a2"]
+        expected = df.iloc[:, :-3]
+
+        tm.assert_frame_equal(result, expected)
+
+    def test_loc_axis_single_level_single_col_indexing_multiindex_col_df(self):
+        # GH29519
+        df = DataFrame(
+            np.arange(27).reshape(3, 9),
+            columns=MultiIndex.from_product([["a1", "a2", "a3"], ["b1", "b2", "b3"]]),
+        )
+        result = df.loc(axis=1)["a1"]
+        expected = df.iloc[:, :3]
+        expected.columns = ["b1", "b2", "b3"]
+
+        tm.assert_frame_equal(result, expected)
+
+    def test_loc_ax_single_level_indexer_simple_df(self):
+        # GH29519
+        # test single level indexing on single index column data frame
+        df = DataFrame(np.arange(9).reshape(3, 3), columns=["a", "b", "c"])
+        result = df.loc(axis=1)["a"]
+        expected = Series(np.array([0, 3, 6]), name="a")
+        tm.assert_series_equal(result, expected)
+
+    def test_per_axis_per_level_setitem(self):
+        # test index maker
+        idx = pd.IndexSlice
+
+        # test multi-index slicing with per axis and per index controls
+        index = MultiIndex.from_tuples(
+            [("A", 1), ("A", 2), ("A", 3), ("B", 1)], names=["one", "two"]
+        )
+        columns = MultiIndex.from_tuples(
+            [("a", "foo"), ("a", "bar"), ("b", "foo"), ("b", "bah")],
+            names=["lvl0", "lvl1"],
+        )
+
+        df_orig = DataFrame(
+            np.arange(16, dtype="int64").reshape(4, 4), index=index, columns=columns
+        )
+        df_orig = df_orig.sort_index(axis=0).sort_index(axis=1)
+
+        # identity
+        df = df_orig.copy()
+        df.loc[(slice(None), slice(None)), :] = 100
+        expected = df_orig.copy()
+        expected.iloc[:, :] = 100
+        tm.assert_frame_equal(df, expected)
+
+        df = df_orig.copy()
+        df.loc(axis=0)[:, :] = 100
+        expected = df_orig.copy()
+        expected.iloc[:, :] = 100
+        tm.assert_frame_equal(df, expected)
+
+        df = df_orig.copy()
+        df.loc[(slice(None), slice(None)), (slice(None), slice(None))] = 100
+        expected = df_orig.copy()
+        expected.iloc[:, :] = 100
+        tm.assert_frame_equal(df, expected)
+
+        df = df_orig.copy()
+        df.loc[:, (slice(None), slice(None))] = 100
+        expected = df_orig.copy()
+        expected.iloc[:, :] = 100
+        tm.assert_frame_equal(df, expected)
+
+        # index
+        df = df_orig.copy()
+        df.loc[(slice(None), [1]), :] = 100
+        expected = df_orig.copy()
+        expected.iloc[[0, 3]] = 100
+        tm.assert_frame_equal(df, expected)
+
+        df = df_orig.copy()
+        df.loc[(slice(None), 1), :] = 100
+        expected = df_orig.copy()
+        expected.iloc[[0, 3]] = 100
+        tm.assert_frame_equal(df, expected)
+
+        df = df_orig.copy()
+        df.loc(axis=0)[:, 1] = 100
+        expected = df_orig.copy()
+        expected.iloc[[0, 3]] = 100
+        tm.assert_frame_equal(df, expected)
+
+        # columns
+        df = df_orig.copy()
+        df.loc[:, (slice(None), ["foo"])] = 100
+        expected = df_orig.copy()
+        expected.iloc[:, [1, 3]] = 100
+        tm.assert_frame_equal(df, expected)
+
+        # both
+        df = df_orig.copy()
+        df.loc[(slice(None), 1), (slice(None), ["foo"])] = 100
+        expected = df_orig.copy()
+        expected.iloc[[0, 3], [1, 3]] = 100
+        tm.assert_frame_equal(df, expected)
+
+        df = df_orig.copy()
+        df.loc[idx[:, 1], idx[:, ["foo"]]] = 100
+        expected = df_orig.copy()
+        expected.iloc[[0, 3], [1, 3]] = 100
+        tm.assert_frame_equal(df, expected)
+
+        df = df_orig.copy()
+        df.loc["A", "a"] = 100
+        expected = df_orig.copy()
+        expected.iloc[0:3, 0:2] = 100
+        tm.assert_frame_equal(df, expected)
+
+        # setting with a list-like
+        df = df_orig.copy()
+        df.loc[(slice(None), 1), (slice(None), ["foo"])] = np.array(
+            [[100, 100], [100, 100]], dtype="int64"
+        )
+        expected = df_orig.copy()
+        expected.iloc[[0, 3], [1, 3]] = 100
+        tm.assert_frame_equal(df, expected)
+
+        # not enough values
+        df = df_orig.copy()
+
+        msg = "setting an array element with a sequence."
+        with pytest.raises(ValueError, match=msg):
+            df.loc[(slice(None), 1), (slice(None), ["foo"])] = np.array(
+                [[100], [100, 100]], dtype="int64"
+            )
+
+        msg = "Must have equal len keys and value when setting with an iterable"
+        with pytest.raises(ValueError, match=msg):
+            df.loc[(slice(None), 1), (slice(None), ["foo"])] = np.array(
+                [100, 100, 100, 100], dtype="int64"
+            )
+
+        # with an alignable rhs
+        df = df_orig.copy()
+        df.loc[(slice(None), 1), (slice(None), ["foo"])] = (
+            df.loc[(slice(None), 1), (slice(None), ["foo"])] * 5
+        )
+        expected = df_orig.copy()
+        expected.iloc[[0, 3], [1, 3]] = expected.iloc[[0, 3], [1, 3]] * 5
+        tm.assert_frame_equal(df, expected)
+
+        df = df_orig.copy()
+        df.loc[(slice(None), 1), (slice(None), ["foo"])] *= df.loc[
+            (slice(None), 1), (slice(None), ["foo"])
+        ]
+        expected = df_orig.copy()
+        expected.iloc[[0, 3], [1, 3]] *= expected.iloc[[0, 3], [1, 3]]
+        tm.assert_frame_equal(df, expected)
+
+        rhs = df_orig.loc[(slice(None), 1), (slice(None), ["foo"])].copy()
+        rhs.loc[:, ("c", "bah")] = 10
+        df = df_orig.copy()
+        df.loc[(slice(None), 1), (slice(None), ["foo"])] *= rhs
+        expected = df_orig.copy()
+        expected.iloc[[0, 3], [1, 3]] *= expected.iloc[[0, 3], [1, 3]]
+        tm.assert_frame_equal(df, expected)
+
+    def test_multiindex_label_slicing_with_negative_step(self):
+        ser = Series(
+            np.arange(20), MultiIndex.from_product([list("abcde"), np.arange(4)])
+        )
+        SLC = pd.IndexSlice
+
+        tm.assert_indexing_slices_equivalent(ser, SLC[::-1], SLC[::-1])
+
+        tm.assert_indexing_slices_equivalent(ser, SLC["d"::-1], SLC[15::-1])
+        tm.assert_indexing_slices_equivalent(ser, SLC[("d",)::-1], SLC[15::-1])
+
+        tm.assert_indexing_slices_equivalent(ser, SLC[:"d":-1], SLC[:11:-1])
+        tm.assert_indexing_slices_equivalent(ser, SLC[:("d",):-1], SLC[:11:-1])
+
+        tm.assert_indexing_slices_equivalent(ser, SLC["d":"b":-1], SLC[15:3:-1])
+        tm.assert_indexing_slices_equivalent(ser, SLC[("d",):"b":-1], SLC[15:3:-1])
+        tm.assert_indexing_slices_equivalent(ser, SLC["d":("b",):-1], SLC[15:3:-1])
+        tm.assert_indexing_slices_equivalent(ser, SLC[("d",):("b",):-1], SLC[15:3:-1])
+        tm.assert_indexing_slices_equivalent(ser, SLC["b":"d":-1], SLC[:0])
+
+        tm.assert_indexing_slices_equivalent(ser, SLC[("c", 2)::-1], SLC[10::-1])
+        tm.assert_indexing_slices_equivalent(ser, SLC[:("c", 2):-1], SLC[:9:-1])
+        tm.assert_indexing_slices_equivalent(
+            ser, SLC[("e", 0):("c", 2):-1], SLC[16:9:-1]
+        )
+
+    def test_multiindex_slice_first_level(self):
+        # GH 12697
+        freq = ["a", "b", "c", "d"]
+        idx = MultiIndex.from_product([freq, range(500)])
+        df = DataFrame(list(range(2000)), index=idx, columns=["Test"])
+        df_slice = df.loc[pd.IndexSlice[:, 30:70], :]
+        result = df_slice.loc["a"]
+        expected = DataFrame(list(range(30, 71)), columns=["Test"], index=range(30, 71))
+        tm.assert_frame_equal(result, expected)
+        result = df_slice.loc["d"]
+        expected = DataFrame(
+            list(range(1530, 1571)), columns=["Test"], index=range(30, 71)
+        )
+        tm.assert_frame_equal(result, expected)
+
+    def test_int_series_slicing(self, multiindex_year_month_day_dataframe_random_data):
+        ymd = multiindex_year_month_day_dataframe_random_data
+        s = ymd["A"]
+        result = s[5:]
+        expected = s.reindex(s.index[5:])
+        tm.assert_series_equal(result, expected)
+
+        s = ymd["A"].copy()
+        exp = ymd["A"].copy()
+        s[5:] = 0
+        exp.iloc[5:] = 0
+        tm.assert_numpy_array_equal(s.values, exp.values)
+
+        result = ymd[5:]
+        expected = ymd.reindex(s.index[5:])
+        tm.assert_frame_equal(result, expected)
+
+    @pytest.mark.parametrize(
+        "dtype, loc, iloc",
+        [
+            # dtype = int, step = -1
+            ("int", slice(None, None, -1), slice(None, None, -1)),
+            ("int", slice(3, None, -1), slice(3, None, -1)),
+            ("int", slice(None, 1, -1), slice(None, 0, -1)),
+            ("int", slice(3, 1, -1), slice(3, 0, -1)),
+            # dtype = int, step = -2
+            ("int", slice(None, None, -2), slice(None, None, -2)),
+            ("int", slice(3, None, -2), slice(3, None, -2)),
+            ("int", slice(None, 1, -2), slice(None, 0, -2)),
+            ("int", slice(3, 1, -2), slice(3, 0, -2)),
+            # dtype = str, step = -1
+            ("str", slice(None, None, -1), slice(None, None, -1)),
+            ("str", slice("d", None, -1), slice(3, None, -1)),
+            ("str", slice(None, "b", -1), slice(None, 0, -1)),
+            ("str", slice("d", "b", -1), slice(3, 0, -1)),
+            # dtype = str, step = -2
+            ("str", slice(None, None, -2), slice(None, None, -2)),
+            ("str", slice("d", None, -2), slice(3, None, -2)),
+            ("str", slice(None, "b", -2), slice(None, 0, -2)),
+            ("str", slice("d", "b", -2), slice(3, 0, -2)),
+        ],
+    )
+    def test_loc_slice_negative_stepsize(self, dtype, loc, iloc):
+        # GH#38071
+        labels = {
+            "str": list("abcde"),
+            "int": range(5),
+        }[dtype]
+
+        mi = MultiIndex.from_arrays([labels] * 2)
+        df = DataFrame(1.0, index=mi, columns=["A"])
+
+        SLC = pd.IndexSlice
+
+        expected = df.iloc[iloc, :]
+        result_get_loc = df.loc[SLC[loc], :]
+        result_get_locs_level_0 = df.loc[SLC[loc, :], :]
+        result_get_locs_level_1 = df.loc[SLC[:, loc], :]
+
+        tm.assert_frame_equal(result_get_loc, expected)
+        tm.assert_frame_equal(result_get_locs_level_0, expected)
+        tm.assert_frame_equal(result_get_locs_level_1, expected)

venv/lib/python3.10/site-packages/pandas/tests/indexing/multiindex/test_sorted.py

@@ -0,0 +1,153 @@
+import numpy as np
+import pytest
+
+from pandas import (
+    NA,
+    DataFrame,
+    MultiIndex,
+    Series,
+    array,
+)
+import pandas._testing as tm
+
+
+class TestMultiIndexSorted:
+    def test_getitem_multilevel_index_tuple_not_sorted(self):
+        index_columns = list("abc")
+        df = DataFrame(
+            [[0, 1, 0, "x"], [0, 0, 1, "y"]], columns=index_columns + ["data"]
+        )
+        df = df.set_index(index_columns)
+        query_index = df.index[:1]
+        rs = df.loc[query_index, "data"]
+
+        xp_idx = MultiIndex.from_tuples([(0, 1, 0)], names=["a", "b", "c"])
+        xp = Series(["x"], index=xp_idx, name="data")
+        tm.assert_series_equal(rs, xp)
+
+    def test_getitem_slice_not_sorted(self, multiindex_dataframe_random_data):
+        frame = multiindex_dataframe_random_data
+        df = frame.sort_index(level=1).T
+
+        # buglet with int typechecking
+        result = df.iloc[:, : np.int32(3)]
+        expected = df.reindex(columns=df.columns[:3])
+        tm.assert_frame_equal(result, expected)
+
+    @pytest.mark.parametrize("key", [None, lambda x: x])
+    def test_frame_getitem_not_sorted2(self, key):
+        # 13431
+        df = DataFrame(
+            {
+                "col1": ["b", "d", "b", "a"],
+                "col2": [3, 1, 1, 2],
+                "data": ["one", "two", "three", "four"],
+            }
+        )
+
+        df2 = df.set_index(["col1", "col2"])
+        df2_original = df2.copy()
+
+        df2.index = df2.index.set_levels(["b", "d", "a"], level="col1")
+        df2.index = df2.index.set_codes([0, 1, 0, 2], level="col1")
+        assert not df2.index.is_monotonic_increasing
+
+        assert df2_original.index.equals(df2.index)
+        expected = df2.sort_index(key=key)
+        assert expected.index.is_monotonic_increasing
+
+        result = df2.sort_index(level=0, key=key)
+        assert result.index.is_monotonic_increasing
+        tm.assert_frame_equal(result, expected)
+
+    def test_sort_values_key(self):
+        arrays = [
+            ["bar", "bar", "baz", "baz", "qux", "qux", "foo", "foo"],
+            ["one", "two", "one", "two", "one", "two", "one", "two"],
+        ]
+        tuples = zip(*arrays)
+        index = MultiIndex.from_tuples(tuples)
+        index = index.sort_values(  # sort by third letter
+            key=lambda x: x.map(lambda entry: entry[2])
+        )
+        result = DataFrame(range(8), index=index)
+
+        arrays = [
+            ["foo", "foo", "bar", "bar", "qux", "qux", "baz", "baz"],
+            ["one", "two", "one", "two", "one", "two", "one", "two"],
+        ]
+        tuples = zip(*arrays)
+        index = MultiIndex.from_tuples(tuples)
+        expected = DataFrame(range(8), index=index)
+
+        tm.assert_frame_equal(result, expected)
+
+    def test_argsort_with_na(self):
+        # GH48495
+        arrays = [
+            array([2, NA, 1], dtype="Int64"),
+            array([1, 2, 3], dtype="Int64"),
+        ]
+        index = MultiIndex.from_arrays(arrays)
+        result = index.argsort()
+        expected = np.array([2, 0, 1], dtype=np.intp)
+        tm.assert_numpy_array_equal(result, expected)
+
+    def test_sort_values_with_na(self):
+        # GH48495
+        arrays = [
+            array([2, NA, 1], dtype="Int64"),
+            array([1, 2, 3], dtype="Int64"),
+        ]
+        index = MultiIndex.from_arrays(arrays)
+        index = index.sort_values()
+        result = DataFrame(range(3), index=index)
+
+        arrays = [
+            array([1, 2, NA], dtype="Int64"),
+            array([3, 1, 2], dtype="Int64"),
+        ]
+        index = MultiIndex.from_arrays(arrays)
+        expected = DataFrame(range(3), index=index)
+
+        tm.assert_frame_equal(result, expected)
+
+    def test_frame_getitem_not_sorted(self, multiindex_dataframe_random_data):
+        frame = multiindex_dataframe_random_data
+        df = frame.T
+        df["foo", "four"] = "foo"
+
+        arrays = [np.array(x) for x in zip(*df.columns.values)]
+
+        result = df["foo"]
+        result2 = df.loc[:, "foo"]
+        expected = df.reindex(columns=df.columns[arrays[0] == "foo"])
+        expected.columns = expected.columns.droplevel(0)
+        tm.assert_frame_equal(result, expected)
+        tm.assert_frame_equal(result2, expected)
+
+        df = df.T
+        result = df.xs("foo")
+        result2 = df.loc["foo"]
+        expected = df.reindex(df.index[arrays[0] == "foo"])
+        expected.index = expected.index.droplevel(0)
+        tm.assert_frame_equal(result, expected)
+        tm.assert_frame_equal(result2, expected)
+
+    def test_series_getitem_not_sorted(self):
+        arrays = [
+            ["bar", "bar", "baz", "baz", "qux", "qux", "foo", "foo"],
+            ["one", "two", "one", "two", "one", "two", "one", "two"],
+        ]
+        tuples = zip(*arrays)
+        index = MultiIndex.from_tuples(tuples)
+        s = Series(np.random.default_rng(2).standard_normal(8), index=index)
+
+        arrays = [np.array(x) for x in zip(*index.values)]
+
+        result = s["qux"]
+        result2 = s.loc["qux"]
+        expected = s[arrays[0] == "qux"]
+        expected.index = expected.index.droplevel(0)
+        tm.assert_series_equal(result, expected)
+        tm.assert_series_equal(result2, expected)