diff --git a/pandas/tests/frame/indexing/test_indexing.py b/pandas/tests/frame/indexing/test_indexing.py
index 9eaa0d0ae6876..4214ac14cba49 100644
--- a/pandas/tests/frame/indexing/test_indexing.py
+++ b/pandas/tests/frame/indexing/test_indexing.py
@@ -66,21 +66,6 @@ def test_getitem_dupe_cols(self):
         with pytest.raises(KeyError, match=re.escape(msg)):
             df[["baf"]]
 
-    @pytest.mark.parametrize("key_type", [iter, np.array, Series, Index])
-    def test_loc_iterable(self, float_frame, key_type):
-        idx = key_type(["A", "B", "C"])
-        result = float_frame.loc[:, idx]
-        expected = float_frame.loc[:, ["A", "B", "C"]]
-        tm.assert_frame_equal(result, expected)
-
-    def test_loc_timedelta_0seconds(self):
-        # GH#10583
-        df = DataFrame(np.random.normal(size=(10, 4)))
-        df.index = pd.timedelta_range(start="0s", periods=10, freq="s")
-        expected = df.loc[pd.Timedelta("0s") :, :]
-        result = df.loc["0s":, :]
-        tm.assert_frame_equal(expected, result)
-
     @pytest.mark.parametrize(
         "idx_type",
         [
@@ -125,28 +110,20 @@ def test_getitem_listlike(self, idx_type, levels, float_frame):
         with pytest.raises(KeyError, match="not in index"):
             frame[idx]
 
-    @pytest.mark.parametrize(
-        "val,expected", [(2 ** 63 - 1, Series([1])), (2 ** 63, Series([2]))]
-    )
-    def test_loc_uint64(self, val, expected):
-        # see gh-19399
-        df = DataFrame([1, 2], index=[2 ** 63 - 1, 2 ** 63])
-        result = df.loc[val]
-
-        expected.name = val
-        tm.assert_series_equal(result, expected)
-
     def test_getitem_callable(self, float_frame):
         # GH 12533
         result = float_frame[lambda x: "A"]
-        tm.assert_series_equal(result, float_frame.loc[:, "A"])
+        expected = float_frame.loc[:, "A"]
+        tm.assert_series_equal(result, expected)
 
         result = float_frame[lambda x: ["A", "B"]]
+        expected = float_frame.loc[:, ["A", "B"]]
         tm.assert_frame_equal(result, float_frame.loc[:, ["A", "B"]])
 
         df = float_frame[:3]
         result = df[lambda x: [True, False, True]]
-        tm.assert_frame_equal(result, float_frame.iloc[[0, 2], :])
+        expected = float_frame.iloc[[0, 2], :]
+        tm.assert_frame_equal(result, expected)
 
     def test_setitem_list(self, float_frame):
 
@@ -181,11 +158,6 @@ def test_setitem_list(self, float_frame):
         expected = Series(["1", "2"], df.columns, name=1)
         tm.assert_series_equal(result, expected)
 
-    def test_setitem_list_not_dataframe(self, float_frame):
-        data = np.random.randn(len(float_frame), 2)
-        float_frame[["A", "B"]] = data
-        tm.assert_almost_equal(float_frame[["A", "B"]].values, data)
-
     def test_setitem_list_of_tuples(self, float_frame):
         tuples = list(zip(float_frame["A"], float_frame["B"]))
         float_frame["tuples"] = tuples
@@ -273,14 +245,6 @@ def test_setitem_multi_index(self):
         df[("joe", "last")] = df[("jolie", "first")].loc[i, j]
         tm.assert_frame_equal(df[("joe", "last")], df[("jolie", "first")])
 
-    def test_setitem_callable(self):
-        # GH 12533
-        df = DataFrame({"A": [1, 2, 3, 4], "B": [5, 6, 7, 8]})
-        df[lambda x: "A"] = [11, 12, 13, 14]
-
-        exp = DataFrame({"A": [11, 12, 13, 14], "B": [5, 6, 7, 8]})
-        tm.assert_frame_equal(df, exp)
-
     def test_setitem_other_callable(self):
         # GH 13299
         def inc(x):
@@ -518,18 +482,13 @@ def test_setitem(self, float_frame):
         df.loc[0] = np.nan
         tm.assert_frame_equal(df, expected)
 
-    @pytest.mark.parametrize("dtype", ["int32", "int64", "float32", "float64"])
-    def test_setitem_dtype(self, dtype, float_frame):
-        arr = np.random.randn(len(float_frame))
-
-        float_frame[dtype] = np.array(arr, dtype=dtype)
-        assert float_frame[dtype].dtype.name == dtype
-
     def test_setitem_tuple(self, float_frame):
         float_frame["A", "B"] = float_frame["A"]
-        tm.assert_series_equal(
-            float_frame["A", "B"], float_frame["A"], check_names=False
-        )
+        assert ("A", "B") in float_frame.columns
+
+        result = float_frame["A", "B"]
+        expected = float_frame["A"]
+        tm.assert_series_equal(result, expected, check_names=False)
 
     def test_setitem_always_copy(self, float_frame):
         s = float_frame["A"].copy()
@@ -588,25 +547,6 @@ def test_setitem_boolean(self, float_frame):
         np.putmask(expected.values, mask.values, df.values * 2)
         tm.assert_frame_equal(df, expected)
 
-    @pytest.mark.parametrize(
-        "mask_type",
-        [lambda df: df > np.abs(df) / 2, lambda df: (df > np.abs(df) / 2).values],
-        ids=["dataframe", "array"],
-    )
-    def test_setitem_boolean_mask(self, mask_type, float_frame):
-
-        # Test for issue #18582
-        df = float_frame.copy()
-        mask = mask_type(df)
-
-        # index with boolean mask
-        result = df.copy()
-        result[mask] = np.nan
-
-        expected = df.copy()
-        expected.values[np.array(mask)] = np.nan
-        tm.assert_frame_equal(result, expected)
-
     def test_setitem_cast(self, float_frame):
         float_frame["D"] = float_frame["D"].astype("i8")
         assert float_frame["D"].dtype == np.int64
@@ -821,19 +761,6 @@ def test_getitem_empty_frame_with_boolean(self):
         df2 = df[df > 0]
         tm.assert_frame_equal(df, df2)
 
-    def test_slice_floats(self):
-        index = [52195.504153, 52196.303147, 52198.369883]
-        df = DataFrame(np.random.rand(3, 2), index=index)
-
-        s1 = df.loc[52195.1:52196.5]
-        assert len(s1) == 2
-
-        s1 = df.loc[52195.1:52196.6]
-        assert len(s1) == 2
-
-        s1 = df.loc[52195.1:52198.9]
-        assert len(s1) == 3
-
     def test_getitem_fancy_slice_integers_step(self):
         df = DataFrame(np.random.randn(10, 5))
 
@@ -883,15 +810,6 @@ def test_fancy_getitem_slice_mixed(self, float_frame, float_string_frame):
 
         assert (float_frame["C"] == 4).all()
 
-    def test_setitem_slice_position(self):
-        # GH#31469
-        df = DataFrame(np.zeros((100, 1)))
-        df[-4:] = 1
-        arr = np.zeros((100, 1))
-        arr[-4:] = 1
-        expected = DataFrame(arr)
-        tm.assert_frame_equal(df, expected)
-
     def test_getitem_setitem_non_ix_labels(self):
         df = tm.makeTimeDataFrame()
 
@@ -1000,14 +918,13 @@ def test_getitem_fancy_ints(self, float_frame):
         expected = float_frame.loc[:, float_frame.columns[[2, 0, 1]]]
         tm.assert_frame_equal(result, expected)
 
-    def test_getitem_setitem_fancy_exceptions(self, float_frame):
-        ix = float_frame.iloc
+    def test_iloc_getitem_setitem_fancy_exceptions(self, float_frame):
         with pytest.raises(IndexingError, match="Too many indexers"):
-            ix[:, :, :]
+            float_frame.iloc[:, :, :]
 
         with pytest.raises(IndexError, match="too many indices for array"):
             # GH#32257 we let numpy do validation, get their exception
-            ix[:, :, :] = 1
+            float_frame.iloc[:, :, :] = 1
 
     def test_getitem_setitem_boolean_misaligned(self, float_frame):
         # boolean index misaligned labels
diff --git a/pandas/tests/frame/indexing/test_setitem.py b/pandas/tests/frame/indexing/test_setitem.py
index e1ce10970f07b..cb04a61b9e1cb 100644
--- a/pandas/tests/frame/indexing/test_setitem.py
+++ b/pandas/tests/frame/indexing/test_setitem.py
@@ -22,6 +22,18 @@
 
 
 class TestDataFrameSetItem:
+    @pytest.mark.parametrize("dtype", ["int32", "int64", "float32", "float64"])
+    def test_setitem_dtype(self, dtype, float_frame):
+        arr = np.random.randn(len(float_frame))
+
+        float_frame[dtype] = np.array(arr, dtype=dtype)
+        assert float_frame[dtype].dtype.name == dtype
+
+    def test_setitem_list_not_dataframe(self, float_frame):
+        data = np.random.randn(len(float_frame), 2)
+        float_frame[["A", "B"]] = data
+        tm.assert_almost_equal(float_frame[["A", "B"]].values, data)
+
     def test_setitem_error_msmgs(self):
 
         # GH 7432
@@ -285,3 +297,45 @@ def test_iloc_setitem_bool_indexer(self, klass):
         df.iloc[indexer, 1] = df.iloc[indexer, 1] * 2
         expected = DataFrame({"flag": ["x", "y", "z"], "value": [2, 3, 4]})
         tm.assert_frame_equal(df, expected)
+
+
+class TestDataFrameSetItemSlicing:
+    def test_setitem_slice_position(self):
+        # GH#31469
+        df = DataFrame(np.zeros((100, 1)))
+        df[-4:] = 1
+        arr = np.zeros((100, 1))
+        arr[-4:] = 1
+        expected = DataFrame(arr)
+        tm.assert_frame_equal(df, expected)
+
+
+class TestDataFrameSetItemCallable:
+    def test_setitem_callable(self):
+        # GH#12533
+        df = DataFrame({"A": [1, 2, 3, 4], "B": [5, 6, 7, 8]})
+        df[lambda x: "A"] = [11, 12, 13, 14]
+
+        exp = DataFrame({"A": [11, 12, 13, 14], "B": [5, 6, 7, 8]})
+        tm.assert_frame_equal(df, exp)
+
+
+class TestDataFrameSetItemBooleanMask:
+    @pytest.mark.parametrize(
+        "mask_type",
+        [lambda df: df > np.abs(df) / 2, lambda df: (df > np.abs(df) / 2).values],
+        ids=["dataframe", "array"],
+    )
+    def test_setitem_boolean_mask(self, mask_type, float_frame):
+
+        # Test for issue #18582
+        df = float_frame.copy()
+        mask = mask_type(df)
+
+        # index with boolean mask
+        result = df.copy()
+        result[mask] = np.nan
+
+        expected = df.copy()
+        expected.values[np.array(mask)] = np.nan
+        tm.assert_frame_equal(result, expected)
diff --git a/pandas/tests/frame/indexing/test_sparse.py b/pandas/tests/frame/indexing/test_sparse.py
index c0cd7faafb4db..47e4ae1f9f9e1 100644
--- a/pandas/tests/frame/indexing/test_sparse.py
+++ b/pandas/tests/frame/indexing/test_sparse.py
@@ -1,12 +1,6 @@
-import numpy as np
-import pytest
-
-import pandas.util._test_decorators as td
-
 import pandas as pd
 import pandas._testing as tm
 from pandas.arrays import SparseArray
-from pandas.core.arrays.sparse import SparseDtype
 
 
 class TestSparseDataFrameIndexing:
@@ -23,34 +17,3 @@ def test_getitem_sparse_column(self):
 
         result = df.loc[:, "A"]
         tm.assert_series_equal(result, expected)
-
-    @pytest.mark.parametrize("spmatrix_t", ["coo_matrix", "csc_matrix", "csr_matrix"])
-    @pytest.mark.parametrize("dtype", [np.int64, np.float64, complex])
-    @td.skip_if_no_scipy
-    def test_loc_getitem_from_spmatrix(self, spmatrix_t, dtype):
-        import scipy.sparse
-
-        spmatrix_t = getattr(scipy.sparse, spmatrix_t)
-
-        # The bug is triggered by a sparse matrix with purely sparse columns.  So the
-        # recipe below generates a rectangular matrix of dimension (5, 7) where all the
-        # diagonal cells are ones, meaning the last two columns are purely sparse.
-        rows, cols = 5, 7
-        spmatrix = spmatrix_t(np.eye(rows, cols, dtype=dtype), dtype=dtype)
-        df = pd.DataFrame.sparse.from_spmatrix(spmatrix)
-
-        # regression test for #34526
-        itr_idx = range(2, rows)
-        result = df.loc[itr_idx].values
-        expected = spmatrix.toarray()[itr_idx]
-        tm.assert_numpy_array_equal(result, expected)
-
-        # regression test for #34540
-        result = df.loc[itr_idx].dtypes.values
-        expected = np.full(cols, SparseDtype(dtype, fill_value=0))
-        tm.assert_numpy_array_equal(result, expected)
-
-    def test_all_sparse(self):
-        df = pd.DataFrame({"A": pd.array([0, 0], dtype=pd.SparseDtype("int64"))})
-        result = df.loc[[0, 1]]
-        tm.assert_frame_equal(result, df)
diff --git a/pandas/tests/indexing/test_at.py b/pandas/tests/indexing/test_at.py
index 9c2d88f1589c2..2e06d8c73d7d1 100644
--- a/pandas/tests/indexing/test_at.py
+++ b/pandas/tests/indexing/test_at.py
@@ -1,14 +1,41 @@
 from datetime import datetime, timezone
 
-import pandas as pd
+import numpy as np
+import pytest
+
+from pandas import DataFrame
 import pandas._testing as tm
 
 
 def test_at_timezone():
     # https://github.com/pandas-dev/pandas/issues/33544
-    result = pd.DataFrame({"foo": [datetime(2000, 1, 1)]})
+    result = DataFrame({"foo": [datetime(2000, 1, 1)]})
     result.at[0, "foo"] = datetime(2000, 1, 2, tzinfo=timezone.utc)
-    expected = pd.DataFrame(
+    expected = DataFrame(
         {"foo": [datetime(2000, 1, 2, tzinfo=timezone.utc)]}, dtype=object
     )
     tm.assert_frame_equal(result, expected)
+
+
+class TestAtWithDuplicates:
+    def test_at_with_duplicate_axes_requires_scalar_lookup(self):
+        # GH#33041 check that falling back to loc doesn't allow non-scalar
+        #  args to slip in
+
+        arr = np.random.randn(6).reshape(3, 2)
+        df = DataFrame(arr, columns=["A", "A"])
+
+        msg = "Invalid call for scalar access"
+        with pytest.raises(ValueError, match=msg):
+            df.at[[1, 2]]
+        with pytest.raises(ValueError, match=msg):
+            df.at[1, ["A"]]
+        with pytest.raises(ValueError, match=msg):
+            df.at[:, "A"]
+
+        with pytest.raises(ValueError, match=msg):
+            df.at[[1, 2]] = 1
+        with pytest.raises(ValueError, match=msg):
+            df.at[1, ["A"]] = 1
+        with pytest.raises(ValueError, match=msg):
+            df.at[:, "A"] = 1
diff --git a/pandas/tests/indexing/test_categorical.py b/pandas/tests/indexing/test_categorical.py
index 854ca176fd2f4..6cdd73d37aec8 100644
--- a/pandas/tests/indexing/test_categorical.py
+++ b/pandas/tests/indexing/test_categorical.py
@@ -73,16 +73,6 @@ def test_loc_scalar(self):
         with pytest.raises(KeyError, match="^1$"):
             df.loc[1]
 
-    def test_getitem_scalar(self):
-
-        cats = Categorical([Timestamp("12-31-1999"), Timestamp("12-31-2000")])
-
-        s = Series([1, 2], index=cats)
-
-        expected = s.iloc[0]
-        result = s[cats[0]]
-        assert result == expected
-
     def test_slicing(self):
         cat = Series(Categorical([1, 2, 3, 4]))
         reversed = cat[::-1]
diff --git a/pandas/tests/indexing/test_datetime.py b/pandas/tests/indexing/test_datetime.py
index 4879f805b5a2d..fad3478499929 100644
--- a/pandas/tests/indexing/test_datetime.py
+++ b/pandas/tests/indexing/test_datetime.py
@@ -1,6 +1,3 @@
-from datetime import date, datetime, timedelta
-
-from dateutil import tz
 import numpy as np
 import pytest
 
@@ -206,26 +203,6 @@ def test_partial_setting_with_datetimelike_dtype(self):
         df.loc[mask, "C"] = df.loc[mask].index
         tm.assert_frame_equal(df, expected)
 
-    def test_loc_setitem_datetime(self):
-
-        # GH 9516
-        dt1 = Timestamp("20130101 09:00:00")
-        dt2 = Timestamp("20130101 10:00:00")
-
-        for conv in [
-            lambda x: x,
-            lambda x: x.to_datetime64(),
-            lambda x: x.to_pydatetime(),
-            lambda x: np.datetime64(x),
-        ]:
-
-            df = DataFrame()
-            df.loc[conv(dt1), "one"] = 100
-            df.loc[conv(dt2), "one"] = 200
-
-            expected = DataFrame({"one": [100.0, 200.0]}, index=[dt1, dt2])
-            tm.assert_frame_equal(df, expected)
-
     def test_series_partial_set_datetime(self):
         # GH 11497
 
@@ -245,7 +222,8 @@ def test_series_partial_set_datetime(self):
         exp = Series(
             [0.2, 0.2, 0.1], index=pd.DatetimeIndex(keys, name="idx"), name="s"
         )
-        tm.assert_series_equal(ser.loc[keys], exp, check_index_type=True)
+        result = ser.loc[keys]
+        tm.assert_series_equal(result, exp, check_index_type=True)
 
         keys = [
             Timestamp("2011-01-03"),
@@ -273,7 +251,8 @@ def test_series_partial_set_period(self):
             pd.Period("2011-01-01", freq="D"),
         ]
         exp = Series([0.2, 0.2, 0.1], index=pd.PeriodIndex(keys, name="idx"), name="s")
-        tm.assert_series_equal(ser.loc[keys], exp, check_index_type=True)
+        result = ser.loc[keys]
+        tm.assert_series_equal(result, exp, check_index_type=True)
 
         keys = [
             pd.Period("2011-01-03", freq="D"),
@@ -297,33 +276,6 @@ def test_nanosecond_getitem_setitem_with_tz(self):
         expected = DataFrame(-1, index=index, columns=["a"])
         tm.assert_frame_equal(result, expected)
 
-    def test_loc_getitem_across_dst(self):
-        # GH 21846
-        idx = pd.date_range(
-            "2017-10-29 01:30:00", tz="Europe/Berlin", periods=5, freq="30 min"
-        )
-        series2 = Series([0, 1, 2, 3, 4], index=idx)
-
-        t_1 = Timestamp("2017-10-29 02:30:00+02:00", tz="Europe/Berlin", freq="30min")
-        t_2 = Timestamp("2017-10-29 02:00:00+01:00", tz="Europe/Berlin", freq="30min")
-        result = series2.loc[t_1:t_2]
-        expected = Series([2, 3], index=idx[2:4])
-        tm.assert_series_equal(result, expected)
-
-        result = series2[t_1]
-        expected = 2
-        assert result == expected
-
-    def test_loc_incremental_setitem_with_dst(self):
-        # GH 20724
-        base = datetime(2015, 11, 1, tzinfo=tz.gettz("US/Pacific"))
-        idxs = [base + timedelta(seconds=i * 900) for i in range(16)]
-        result = Series([0], index=[idxs[0]])
-        for ts in idxs:
-            result.loc[ts] = 1
-        expected = Series(1, index=idxs)
-        tm.assert_series_equal(result, expected)
-
     def test_loc_setitem_with_existing_dst(self):
         # GH 18308
         start = Timestamp("2017-10-29 00:00:00+0200", tz="Europe/Madrid")
@@ -339,39 +291,3 @@ def test_loc_setitem_with_existing_dst(self):
             dtype=object,
         )
         tm.assert_frame_equal(result, expected)
-
-    def test_loc_str_slicing(self):
-        ix = pd.period_range(start="2017-01-01", end="2018-01-01", freq="M")
-        ser = ix.to_series()
-        result = ser.loc[:"2017-12"]
-        expected = ser.iloc[:-1]
-
-        tm.assert_series_equal(result, expected)
-
-    def test_loc_label_slicing(self):
-        ix = pd.period_range(start="2017-01-01", end="2018-01-01", freq="M")
-        ser = ix.to_series()
-        result = ser.loc[: ix[-2]]
-        expected = ser.iloc[:-1]
-
-        tm.assert_series_equal(result, expected)
-
-    @pytest.mark.parametrize(
-        "slice_, positions",
-        [
-            [slice(date(2018, 1, 1), None), [0, 1, 2]],
-            [slice(date(2019, 1, 2), None), [2]],
-            [slice(date(2020, 1, 1), None), []],
-            [slice(None, date(2020, 1, 1)), [0, 1, 2]],
-            [slice(None, date(2019, 1, 1)), [0]],
-        ],
-    )
-    def test_getitem_slice_date(self, slice_, positions):
-        # https://github.com/pandas-dev/pandas/issues/31501
-        s = Series(
-            [0, 1, 2],
-            pd.DatetimeIndex(["2019-01-01", "2019-01-01T06:00:00", "2019-01-02"]),
-        )
-        result = s[slice_]
-        expected = s.take(positions)
-        tm.assert_series_equal(result, expected)
diff --git a/pandas/tests/indexing/test_loc.py b/pandas/tests/indexing/test_loc.py
index c1a5db992d3df..fff4c0f78f38a 100644
--- a/pandas/tests/indexing/test_loc.py
+++ b/pandas/tests/indexing/test_loc.py
@@ -1,15 +1,28 @@
 """ test label based indexing with loc """
-from datetime import time
+from datetime import datetime, time, timedelta
 from io import StringIO
 import re
 
+from dateutil.tz import gettz
 import numpy as np
 import pytest
 
 from pandas.compat.numpy import is_numpy_dev
+import pandas.util._test_decorators as td
 
 import pandas as pd
-from pandas import DataFrame, MultiIndex, Series, Timestamp, date_range
+from pandas import (
+    DataFrame,
+    Index,
+    MultiIndex,
+    Series,
+    SparseDtype,
+    Timedelta,
+    Timestamp,
+    date_range,
+    timedelta_range,
+    to_datetime,
+)
 import pandas._testing as tm
 from pandas.api.types import is_scalar
 from pandas.tests.indexing.common import Base
@@ -1014,6 +1027,73 @@ def test_loc_getitem_time_object(self, frame_or_series):
         expected.index = expected.index._with_freq(None)
         tm.assert_equal(result, expected)
 
+    @pytest.mark.parametrize("spmatrix_t", ["coo_matrix", "csc_matrix", "csr_matrix"])
+    @pytest.mark.parametrize("dtype", [np.int64, np.float64, complex])
+    @td.skip_if_no_scipy
+    def test_loc_getitem_range_from_spmatrix(self, spmatrix_t, dtype):
+        import scipy.sparse
+
+        spmatrix_t = getattr(scipy.sparse, spmatrix_t)
+
+        # The bug is triggered by a sparse matrix with purely sparse columns.  So the
+        # recipe below generates a rectangular matrix of dimension (5, 7) where all the
+        # diagonal cells are ones, meaning the last two columns are purely sparse.
+        rows, cols = 5, 7
+        spmatrix = spmatrix_t(np.eye(rows, cols, dtype=dtype), dtype=dtype)
+        df = DataFrame.sparse.from_spmatrix(spmatrix)
+
+        # regression test for GH#34526
+        itr_idx = range(2, rows)
+        result = df.loc[itr_idx].values
+        expected = spmatrix.toarray()[itr_idx]
+        tm.assert_numpy_array_equal(result, expected)
+
+        # regression test for GH#34540
+        result = df.loc[itr_idx].dtypes.values
+        expected = np.full(cols, SparseDtype(dtype, fill_value=0))
+        tm.assert_numpy_array_equal(result, expected)
+
+    def test_loc_getitem_listlike_all_retains_sparse(self):
+        df = DataFrame({"A": pd.array([0, 0], dtype=SparseDtype("int64"))})
+        result = df.loc[[0, 1]]
+        tm.assert_frame_equal(result, df)
+
+    @pytest.mark.parametrize("key_type", [iter, np.array, Series, Index])
+    def test_loc_getitem_iterable(self, float_frame, key_type):
+        idx = key_type(["A", "B", "C"])
+        result = float_frame.loc[:, idx]
+        expected = float_frame.loc[:, ["A", "B", "C"]]
+        tm.assert_frame_equal(result, expected)
+
+    def test_loc_getitem_timedelta_0seconds(self):
+        # GH#10583
+        df = DataFrame(np.random.normal(size=(10, 4)))
+        df.index = timedelta_range(start="0s", periods=10, freq="s")
+        expected = df.loc[Timedelta("0s") :, :]
+        result = df.loc["0s":, :]
+        tm.assert_frame_equal(expected, result)
+
+    @pytest.mark.parametrize(
+        "val,expected", [(2 ** 63 - 1, Series([1])), (2 ** 63, Series([2]))]
+    )
+    def test_loc_getitem_uint64_scalar(self, val, expected):
+        # see GH#19399
+        df = DataFrame([1, 2], index=[2 ** 63 - 1, 2 ** 63])
+        result = df.loc[val]
+
+        expected.name = val
+        tm.assert_series_equal(result, expected)
+
+    def test_loc_setitem_int_label_with_float64index(self):
+        # note labels are floats
+        ser = Series(["a", "b", "c"], index=[0, 0.5, 1])
+        tmp = ser.copy()
+
+        ser.loc[1] = "zoo"
+        tmp.iloc[2] = "zoo"
+
+        tm.assert_series_equal(ser, tmp)
+
 
 class TestLocWithMultiIndex:
     @pytest.mark.parametrize(
@@ -1103,6 +1183,11 @@ def test_loc_setitem_multiindex_slice(self):
 
         tm.assert_series_equal(result, expected)
 
+    def test_loc_getitem_slice_datetime_objs_with_datetimeindex(self):
+        times = date_range("2000-01-01", freq="10min", periods=100000)
+        ser = Series(range(100000), times)
+        ser.loc[datetime(1900, 1, 1) : datetime(2100, 1, 1)]
+
 
 class TestLocSetitemWithExpansion:
     @pytest.mark.slow
@@ -1113,6 +1198,59 @@ def test_loc_setitem_with_expansion_large_dataframe(self):
         expected = DataFrame({"x": range(10 ** 6 + 1)}, dtype="int64")
         tm.assert_frame_equal(result, expected)
 
+    def test_loc_setitem_empty_series(self):
+        # GH#5226
+
+        # partially set with an empty object series
+        ser = Series(dtype=object)
+        ser.loc[1] = 1
+        tm.assert_series_equal(ser, Series([1], index=[1]))
+        ser.loc[3] = 3
+        tm.assert_series_equal(ser, Series([1, 3], index=[1, 3]))
+
+        ser = Series(dtype=object)
+        ser.loc[1] = 1.0
+        tm.assert_series_equal(ser, Series([1.0], index=[1]))
+        ser.loc[3] = 3.0
+        tm.assert_series_equal(ser, Series([1.0, 3.0], index=[1, 3]))
+
+        ser = Series(dtype=object)
+        ser.loc["foo"] = 1
+        tm.assert_series_equal(ser, Series([1], index=["foo"]))
+        ser.loc["bar"] = 3
+        tm.assert_series_equal(ser, Series([1, 3], index=["foo", "bar"]))
+        ser.loc[3] = 4
+        tm.assert_series_equal(ser, Series([1, 3, 4], index=["foo", "bar", 3]))
+
+    def test_loc_setitem_incremental_with_dst(self):
+        # GH#20724
+        base = datetime(2015, 11, 1, tzinfo=gettz("US/Pacific"))
+        idxs = [base + timedelta(seconds=i * 900) for i in range(16)]
+        result = Series([0], index=[idxs[0]])
+        for ts in idxs:
+            result.loc[ts] = 1
+        expected = Series(1, index=idxs)
+        tm.assert_series_equal(result, expected)
+
+    def test_loc_setitem_datetime_keys_cast(self):
+        # GH#9516
+        dt1 = Timestamp("20130101 09:00:00")
+        dt2 = Timestamp("20130101 10:00:00")
+
+        for conv in [
+            lambda x: x,
+            lambda x: x.to_datetime64(),
+            lambda x: x.to_pydatetime(),
+            lambda x: np.datetime64(x),
+        ]:
+
+            df = DataFrame()
+            df.loc[conv(dt1), "one"] = 100
+            df.loc[conv(dt2), "one"] = 200
+
+            expected = DataFrame({"one": [100.0, 200.0]}, index=[dt1, dt2])
+            tm.assert_frame_equal(df, expected)
+
 
 class TestLocCallable:
     def test_frame_loc_getitem_callable(self):
@@ -1280,6 +1418,85 @@ def test_frame_loc_setitem_callable(self):
         tm.assert_frame_equal(res, exp)
 
 
+class TestPartialStringSlicing:
+    def test_loc_getitem_partial_string_slicing_datetimeindex(self):
+        # GH#35509
+        df = DataFrame(
+            {"col1": ["a", "b", "c"], "col2": [1, 2, 3]},
+            index=to_datetime(["2020-08-01", "2020-07-02", "2020-08-05"]),
+        )
+        expected = DataFrame(
+            {"col1": ["a", "c"], "col2": [1, 3]},
+            index=to_datetime(["2020-08-01", "2020-08-05"]),
+        )
+        result = df.loc["2020-08"]
+        tm.assert_frame_equal(result, expected)
+
+    def test_loc_getitem_partial_string_slicing_with_periodindex(self):
+        pi = pd.period_range(start="2017-01-01", end="2018-01-01", freq="M")
+        ser = pi.to_series()
+        result = ser.loc[:"2017-12"]
+        expected = ser.iloc[:-1]
+
+        tm.assert_series_equal(result, expected)
+
+    def test_loc_getitem_partial_string_slicing_with_timedeltaindex(self):
+        ix = timedelta_range(start="1 day", end="2 days", freq="1H")
+        ser = ix.to_series()
+        result = ser.loc[:"1 days"]
+        expected = ser.iloc[:-1]
+
+        tm.assert_series_equal(result, expected)
+
+
+class TestLabelSlicing:
+    def test_loc_getitem_label_slice_across_dst(self):
+        # GH#21846
+        idx = date_range(
+            "2017-10-29 01:30:00", tz="Europe/Berlin", periods=5, freq="30 min"
+        )
+        series2 = Series([0, 1, 2, 3, 4], index=idx)
+
+        t_1 = Timestamp("2017-10-29 02:30:00+02:00", tz="Europe/Berlin", freq="30min")
+        t_2 = Timestamp("2017-10-29 02:00:00+01:00", tz="Europe/Berlin", freq="30min")
+        result = series2.loc[t_1:t_2]
+        expected = Series([2, 3], index=idx[2:4])
+        tm.assert_series_equal(result, expected)
+
+        result = series2[t_1]
+        expected = 2
+        assert result == expected
+
+    def test_loc_getitem_label_slice_period(self):
+        ix = pd.period_range(start="2017-01-01", end="2018-01-01", freq="M")
+        ser = ix.to_series()
+        result = ser.loc[: ix[-2]]
+        expected = ser.iloc[:-1]
+
+        tm.assert_series_equal(result, expected)
+
+    def test_loc_getitem_label_slice_timedelta64(self):
+        ix = timedelta_range(start="1 day", end="2 days", freq="1H")
+        ser = ix.to_series()
+        result = ser.loc[: ix[-2]]
+        expected = ser.iloc[:-1]
+
+        tm.assert_series_equal(result, expected)
+
+    def test_loc_getitem_slice_floats_inexact(self):
+        index = [52195.504153, 52196.303147, 52198.369883]
+        df = DataFrame(np.random.rand(3, 2), index=index)
+
+        s1 = df.loc[52195.1:52196.5]
+        assert len(s1) == 2
+
+        s1 = df.loc[52195.1:52196.6]
+        assert len(s1) == 2
+
+        s1 = df.loc[52195.1:52198.9]
+        assert len(s1) == 3
+
+
 def test_series_loc_getitem_label_list_missing_values():
     # gh-11428
     key = np.array(
diff --git a/pandas/tests/indexing/test_partial.py b/pandas/tests/indexing/test_partial.py
index 80b7947eb5239..01db937153b3a 100644
--- a/pandas/tests/indexing/test_partial.py
+++ b/pandas/tests/indexing/test_partial.py
@@ -351,31 +351,6 @@ def test_partial_set_invalid(self):
         tm.assert_index_equal(df.index, Index(orig.index.tolist() + ["a"]))
         assert df.index.dtype == "object"
 
-    def test_partial_set_empty_series(self):
-
-        # GH5226
-
-        # partially set with an empty object series
-        s = Series(dtype=object)
-        s.loc[1] = 1
-        tm.assert_series_equal(s, Series([1], index=[1]))
-        s.loc[3] = 3
-        tm.assert_series_equal(s, Series([1, 3], index=[1, 3]))
-
-        s = Series(dtype=object)
-        s.loc[1] = 1.0
-        tm.assert_series_equal(s, Series([1.0], index=[1]))
-        s.loc[3] = 3.0
-        tm.assert_series_equal(s, Series([1.0, 3.0], index=[1, 3]))
-
-        s = Series(dtype=object)
-        s.loc["foo"] = 1
-        tm.assert_series_equal(s, Series([1], index=["foo"]))
-        s.loc["bar"] = 3
-        tm.assert_series_equal(s, Series([1, 3], index=["foo", "bar"]))
-        s.loc[3] = 4
-        tm.assert_series_equal(s, Series([1, 3, 4], index=["foo", "bar", 3]))
-
     def test_partial_set_empty_frame(self):
 
         # partially set with an empty object
@@ -504,10 +479,12 @@ def test_partial_set_empty_frame_set_series(self):
         # GH 5756
         # setting with empty Series
         df = DataFrame(Series(dtype=object))
-        tm.assert_frame_equal(df, DataFrame({0: Series(dtype=object)}))
+        expected = DataFrame({0: Series(dtype=object)})
+        tm.assert_frame_equal(df, expected)
 
         df = DataFrame(Series(name="foo", dtype=object))
-        tm.assert_frame_equal(df, DataFrame({"foo": Series(dtype=object)}))
+        expected = DataFrame({"foo": Series(dtype=object)})
+        tm.assert_frame_equal(df, expected)
 
     def test_partial_set_empty_frame_empty_copy_assignment(self):
         # GH 5932
@@ -565,19 +542,17 @@ def test_partial_set_empty_frame_empty_consistencies(self):
         ],
     )
     def test_loc_with_list_of_strings_representing_datetimes(
-        self, idx, labels, expected_idx
+        self, idx, labels, expected_idx, frame_or_series
     ):
         # GH 11278
-        s = Series(range(20), index=idx)
-        df = DataFrame(range(20), index=idx)
+        obj = frame_or_series(range(20), index=idx)
 
         expected_value = [3, 7, 11]
-        expected_s = Series(expected_value, expected_idx)
-        expected_df = DataFrame(expected_value, expected_idx)
+        expected = frame_or_series(expected_value, expected_idx)
 
-        tm.assert_series_equal(expected_s, s.loc[labels])
-        tm.assert_series_equal(expected_s, s[labels])
-        tm.assert_frame_equal(expected_df, df.loc[labels])
+        tm.assert_equal(expected, obj.loc[labels])
+        if frame_or_series is Series:
+            tm.assert_series_equal(expected, obj[labels])
 
     @pytest.mark.parametrize(
         "idx,labels",
@@ -651,16 +626,6 @@ def test_loc_with_list_of_strings_representing_datetimes_not_matched_type(
         with pytest.raises(KeyError, match=msg):
             df.loc[labels]
 
-    def test_indexing_timeseries_regression(self):
-        # Issue 34860
-        arr = date_range("1/1/2008", "1/1/2009")
-        result = arr.to_series()["2008"]
-
-        rng = date_range(start="2008-01-01", end="2008-12-31")
-        expected = Series(rng, index=rng)
-
-        tm.assert_series_equal(result, expected)
-
     def test_index_name_empty(self):
         # GH 31368
         df = DataFrame({}, index=pd.RangeIndex(0, name="df_index"))
@@ -689,16 +654,3 @@ def test_slice_irregular_datetime_index_with_nan(self):
         expected = DataFrame(range(len(index[:3])), index=index[:3])
         result = df["2012-01-01":"2012-01-04"]
         tm.assert_frame_equal(result, expected)
-
-    def test_slice_datetime_index(self):
-        # GH35509
-        df = DataFrame(
-            {"col1": ["a", "b", "c"], "col2": [1, 2, 3]},
-            index=pd.to_datetime(["2020-08-01", "2020-07-02", "2020-08-05"]),
-        )
-        expected = DataFrame(
-            {"col1": ["a", "c"], "col2": [1, 3]},
-            index=pd.to_datetime(["2020-08-01", "2020-08-05"]),
-        )
-        result = df.loc["2020-08"]
-        tm.assert_frame_equal(result, expected)
diff --git a/pandas/tests/indexing/test_scalar.py b/pandas/tests/indexing/test_scalar.py
index 4337f01ea33e0..72296bb222a5a 100644
--- a/pandas/tests/indexing/test_scalar.py
+++ b/pandas/tests/indexing/test_scalar.py
@@ -146,28 +146,6 @@ def test_frame_at_with_duplicate_axes(self):
         expected = Series([2.0, 2.0], index=["A", "A"], name=1)
         tm.assert_series_equal(df.iloc[1], expected)
 
-    def test_frame_at_with_duplicate_axes_requires_scalar_lookup(self):
-        # GH#33041 check that falling back to loc doesn't allow non-scalar
-        #  args to slip in
-
-        arr = np.random.randn(6).reshape(3, 2)
-        df = DataFrame(arr, columns=["A", "A"])
-
-        msg = "Invalid call for scalar access"
-        with pytest.raises(ValueError, match=msg):
-            df.at[[1, 2]]
-        with pytest.raises(ValueError, match=msg):
-            df.at[1, ["A"]]
-        with pytest.raises(ValueError, match=msg):
-            df.at[:, "A"]
-
-        with pytest.raises(ValueError, match=msg):
-            df.at[[1, 2]] = 1
-        with pytest.raises(ValueError, match=msg):
-            df.at[1, ["A"]] = 1
-        with pytest.raises(ValueError, match=msg):
-            df.at[:, "A"] = 1
-
     def test_series_at_raises_type_error(self):
         # at should not fallback
         # GH 7814
diff --git a/pandas/tests/indexing/test_timedelta.py b/pandas/tests/indexing/test_timedelta.py
index 7da368e4bb321..9461bb74b2a87 100644
--- a/pandas/tests/indexing/test_timedelta.py
+++ b/pandas/tests/indexing/test_timedelta.py
@@ -104,19 +104,3 @@ def test_roundtrip_thru_setitem(self):
 
         assert expected == result
         tm.assert_frame_equal(df, df_copy)
-
-    def test_loc_str_slicing(self):
-        ix = pd.timedelta_range(start="1 day", end="2 days", freq="1H")
-        ser = ix.to_series()
-        result = ser.loc[:"1 days"]
-        expected = ser.iloc[:-1]
-
-        tm.assert_series_equal(result, expected)
-
-    def test_loc_slicing(self):
-        ix = pd.timedelta_range(start="1 day", end="2 days", freq="1H")
-        ser = ix.to_series()
-        result = ser.loc[: ix[-2]]
-        expected = ser.iloc[:-1]
-
-        tm.assert_series_equal(result, expected)
diff --git a/pandas/tests/series/indexing/test_datetime.py b/pandas/tests/series/indexing/test_datetime.py
index c25b8936c1b29..b2fc2e2d0619d 100644
--- a/pandas/tests/series/indexing/test_datetime.py
+++ b/pandas/tests/series/indexing/test_datetime.py
@@ -4,14 +4,23 @@
 from datetime import datetime, timedelta
 import re
 
+from dateutil.tz import gettz, tzutc
 import numpy as np
 import pytest
+import pytz
 
-from pandas._libs import iNaT
-import pandas._libs.index as _index
+from pandas._libs import iNaT, index as libindex
 
 import pandas as pd
-from pandas import DataFrame, DatetimeIndex, NaT, Series, Timestamp, date_range
+from pandas import (
+    DataFrame,
+    DatetimeIndex,
+    NaT,
+    Series,
+    Timestamp,
+    date_range,
+    period_range,
+)
 import pandas._testing as tm
 
 
@@ -65,13 +74,6 @@ def test_dti_reset_index_round_trip():
     assert df.reset_index()["Date"][0] == stamp
 
 
-@pytest.mark.slow
-def test_slice_locs_indexerror():
-    times = [datetime(2000, 1, 1) + timedelta(minutes=i * 10) for i in range(100000)]
-    s = Series(range(100000), times)
-    s.loc[datetime(1900, 1, 1) : datetime(2100, 1, 1)]
-
-
 def test_slicing_datetimes():
     # GH 7523
 
@@ -114,8 +116,6 @@ def test_slicing_datetimes():
 
 
 def test_getitem_setitem_datetime_tz_pytz():
-    from pytz import timezone as tz
-
     N = 50
     # testing with timezone, GH #2785
     rng = date_range("1/1/1990", periods=N, freq="H", tz="US/Eastern")
@@ -134,23 +134,20 @@ def test_getitem_setitem_datetime_tz_pytz():
 
     # repeat with datetimes
     result = ts.copy()
-    result[datetime(1990, 1, 1, 9, tzinfo=tz("UTC"))] = 0
-    result[datetime(1990, 1, 1, 9, tzinfo=tz("UTC"))] = ts[4]
+    result[datetime(1990, 1, 1, 9, tzinfo=pytz.timezone("UTC"))] = 0
+    result[datetime(1990, 1, 1, 9, tzinfo=pytz.timezone("UTC"))] = ts[4]
     tm.assert_series_equal(result, ts)
 
     result = ts.copy()
 
     # comparison dates with datetime MUST be localized!
-    date = tz("US/Central").localize(datetime(1990, 1, 1, 3))
+    date = pytz.timezone("US/Central").localize(datetime(1990, 1, 1, 3))
     result[date] = 0
     result[date] = ts[4]
     tm.assert_series_equal(result, ts)
 
 
 def test_getitem_setitem_datetime_tz_dateutil():
-    from dateutil.tz import tzutc
-
-    from pandas._libs.tslibs.timezones import dateutil_gettz as gettz
 
     tz = (
         lambda x: tzutc() if x == "UTC" else gettz(x)
@@ -295,7 +292,6 @@ def test_getitem_setitem_datetimeindex():
 
 
 def test_getitem_setitem_periodindex():
-    from pandas import period_range
 
     N = 50
     rng = period_range("1/1/1990", periods=N, freq="H")
@@ -466,72 +462,50 @@ def test_duplicate_dates_indexing(dups):
     assert ts[datetime(2000, 1, 6)] == 0
 
 
-def test_range_slice():
-    idx = DatetimeIndex(["1/1/2000", "1/2/2000", "1/2/2000", "1/3/2000", "1/4/2000"])
-
-    ts = Series(np.random.randn(len(idx)), index=idx)
-
-    result = ts["1/2/2000":]
-    expected = ts[1:]
-    tm.assert_series_equal(result, expected)
-
-    result = ts["1/2/2000":"1/3/2000"]
-    expected = ts[1:4]
-    tm.assert_series_equal(result, expected)
-
-
 def test_groupby_average_dup_values(dups):
     result = dups.groupby(level=0).mean()
     expected = dups.groupby(dups.index).mean()
     tm.assert_series_equal(result, expected)
 
 
-def test_indexing_over_size_cutoff():
-    import datetime
-
+def test_indexing_over_size_cutoff(monkeypatch):
     # #1821
 
-    old_cutoff = _index._SIZE_CUTOFF
-    try:
-        _index._SIZE_CUTOFF = 1000
-
-        # create large list of non periodic datetime
-        dates = []
-        sec = datetime.timedelta(seconds=1)
-        half_sec = datetime.timedelta(microseconds=500000)
-        d = datetime.datetime(2011, 12, 5, 20, 30)
-        n = 1100
-        for i in range(n):
-            dates.append(d)
-            dates.append(d + sec)
-            dates.append(d + sec + half_sec)
-            dates.append(d + sec + sec + half_sec)
-            d += 3 * sec
-
-        # duplicate some values in the list
-        duplicate_positions = np.random.randint(0, len(dates) - 1, 20)
-        for p in duplicate_positions:
-            dates[p + 1] = dates[p]
-
-        df = DataFrame(
-            np.random.randn(len(dates), 4), index=dates, columns=list("ABCD")
-        )
-
-        pos = n * 3
-        timestamp = df.index[pos]
-        assert timestamp in df.index
-
-        # it works!
-        df.loc[timestamp]
-        assert len(df.loc[[timestamp]]) > 0
-    finally:
-        _index._SIZE_CUTOFF = old_cutoff
+    monkeypatch.setattr(libindex, "_SIZE_CUTOFF", 1000)
+
+    # create large list of non periodic datetime
+    dates = []
+    sec = timedelta(seconds=1)
+    half_sec = timedelta(microseconds=500000)
+    d = datetime(2011, 12, 5, 20, 30)
+    n = 1100
+    for i in range(n):
+        dates.append(d)
+        dates.append(d + sec)
+        dates.append(d + sec + half_sec)
+        dates.append(d + sec + sec + half_sec)
+        d += 3 * sec
+
+    # duplicate some values in the list
+    duplicate_positions = np.random.randint(0, len(dates) - 1, 20)
+    for p in duplicate_positions:
+        dates[p + 1] = dates[p]
+
+    df = DataFrame(np.random.randn(len(dates), 4), index=dates, columns=list("ABCD"))
+
+    pos = n * 3
+    timestamp = df.index[pos]
+    assert timestamp in df.index
+
+    # it works!
+    df.loc[timestamp]
+    assert len(df.loc[[timestamp]]) > 0
 
 
 def test_indexing_over_size_cutoff_period_index(monkeypatch):
     # GH 27136
 
-    monkeypatch.setattr(_index, "_SIZE_CUTOFF", 1000)
+    monkeypatch.setattr(libindex, "_SIZE_CUTOFF", 1000)
 
     n = 1100
     idx = pd.period_range("1/1/2000", freq="T", periods=n)
@@ -654,19 +628,3 @@ def test_indexing():
     msg = r"Timestamp\('2012-01-02 18:01:02-0600', tz='US/Central', freq='S'\)"
     with pytest.raises(KeyError, match=msg):
         df[df.index[2]]
-
-
-"""
-test NaT support
-"""
-
-
-def test_setitem_tuple_with_datetimetz():
-    # GH 20441
-    arr = date_range("2017", periods=4, tz="US/Eastern")
-    index = [(0, 1), (0, 2), (0, 3), (0, 4)]
-    result = Series(arr, index=index)
-    expected = result.copy()
-    result[(0, 1)] = np.nan
-    expected.iloc[0] = np.nan
-    tm.assert_series_equal(result, expected)
diff --git a/pandas/tests/series/indexing/test_getitem.py b/pandas/tests/series/indexing/test_getitem.py
index 2933983a5b18b..71bcce12796f5 100644
--- a/pandas/tests/series/indexing/test_getitem.py
+++ b/pandas/tests/series/indexing/test_getitem.py
@@ -1,7 +1,7 @@
 """
 Series.__getitem__ test classes are organized by the type of key passed.
 """
-from datetime import datetime, time
+from datetime import date, datetime, time
 
 import numpy as np
 import pytest
@@ -9,7 +9,16 @@
 from pandas._libs.tslibs import conversion, timezones
 
 import pandas as pd
-from pandas import DataFrame, Index, Series, Timestamp, date_range, period_range
+from pandas import (
+    Categorical,
+    DataFrame,
+    DatetimeIndex,
+    Index,
+    Series,
+    Timestamp,
+    date_range,
+    period_range,
+)
 import pandas._testing as tm
 from pandas.core.indexing import IndexingError
 
@@ -93,8 +102,46 @@ def test_getitem_time_object(self):
         result.index = result.index._with_freq(None)
         tm.assert_series_equal(result, expected)
 
+    # ------------------------------------------------------------------
+    # Series with CategoricalIndex
+
+    def test_getitem_scalar_categorical_index(self):
+        cats = Categorical([Timestamp("12-31-1999"), Timestamp("12-31-2000")])
+
+        ser = Series([1, 2], index=cats)
+
+        expected = ser.iloc[0]
+        result = ser[cats[0]]
+        assert result == expected
+
 
 class TestSeriesGetitemSlices:
+    def test_getitem_partial_str_slice_with_datetimeindex(self):
+        # GH#34860
+        arr = date_range("1/1/2008", "1/1/2009")
+        ser = arr.to_series()
+        result = ser["2008"]
+
+        rng = date_range(start="2008-01-01", end="2008-12-31")
+        expected = Series(rng, index=rng)
+
+        tm.assert_series_equal(result, expected)
+
+    def test_getitem_slice_strings_with_datetimeindex(self):
+        idx = DatetimeIndex(
+            ["1/1/2000", "1/2/2000", "1/2/2000", "1/3/2000", "1/4/2000"]
+        )
+
+        ts = Series(np.random.randn(len(idx)), index=idx)
+
+        result = ts["1/2/2000":]
+        expected = ts[1:]
+        tm.assert_series_equal(result, expected)
+
+        result = ts["1/2/2000":"1/3/2000"]
+        expected = ts[1:4]
+        tm.assert_series_equal(result, expected)
+
     def test_getitem_slice_2d(self, datetime_series):
         # GH#30588 multi-dimensional indexing deprecated
 
@@ -119,6 +166,26 @@ def test_getitem_median_slice_bug(self):
         expected = s[indexer[0]]
         tm.assert_series_equal(result, expected)
 
+    @pytest.mark.parametrize(
+        "slc, positions",
+        [
+            [slice(date(2018, 1, 1), None), [0, 1, 2]],
+            [slice(date(2019, 1, 2), None), [2]],
+            [slice(date(2020, 1, 1), None), []],
+            [slice(None, date(2020, 1, 1)), [0, 1, 2]],
+            [slice(None, date(2019, 1, 1)), [0]],
+        ],
+    )
+    def test_getitem_slice_date(self, slc, positions):
+        # https://github.com/pandas-dev/pandas/issues/31501
+        ser = Series(
+            [0, 1, 2],
+            DatetimeIndex(["2019-01-01", "2019-01-01T06:00:00", "2019-01-02"]),
+        )
+        result = ser[slc]
+        expected = ser.take(positions)
+        tm.assert_series_equal(result, expected)
+
 
 class TestSeriesGetitemListLike:
     @pytest.mark.parametrize("box", [list, np.array, pd.Index, pd.Series])
diff --git a/pandas/tests/series/indexing/test_numeric.py b/pandas/tests/series/indexing/test_numeric.py
index f35f1375732cb..86af29eac1bae 100644
--- a/pandas/tests/series/indexing/test_numeric.py
+++ b/pandas/tests/series/indexing/test_numeric.py
@@ -71,17 +71,6 @@ def test_getitem_setitem_slice_integers():
     assert not (s[4:] == 0).any()
 
 
-def test_setitem_float_labels():
-    # note labels are floats
-    s = Series(["a", "b", "c"], index=[0, 0.5, 1])
-    tmp = s.copy()
-
-    s.loc[1] = "zoo"
-    tmp.iloc[2] = "zoo"
-
-    tm.assert_series_equal(s, tmp)
-
-
 def test_slice_float_get_set(datetime_series):
     msg = (
         "cannot do slice indexing on DatetimeIndex with these indexers "
diff --git a/pandas/tests/series/indexing/test_setitem.py b/pandas/tests/series/indexing/test_setitem.py
index b4c5ac0195d26..7e25e5200d610 100644
--- a/pandas/tests/series/indexing/test_setitem.py
+++ b/pandas/tests/series/indexing/test_setitem.py
@@ -61,6 +61,16 @@ def test_setitem_with_different_tz_casts_to_object(self):
         )
         tm.assert_series_equal(ser, expected)
 
+    def test_setitem_tuple_with_datetimetz_values(self):
+        # GH#20441
+        arr = date_range("2017", periods=4, tz="US/Eastern")
+        index = [(0, 1), (0, 2), (0, 3), (0, 4)]
+        result = Series(arr, index=index)
+        expected = result.copy()
+        result[(0, 1)] = np.nan
+        expected.iloc[0] = np.nan
+        tm.assert_series_equal(result, expected)
+
 
 class TestSetitemPeriodDtype:
     @pytest.mark.parametrize("na_val", [None, np.nan])