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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)