From eed34af7de4709d66d05a8a9a2e7898600bbdc85 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 11:38:52 -0800
Subject: [PATCH 01/26] Clean up axis fixtures

---
 pandas/conftest.py                            | 19 ------------------
 pandas/tests/frame/methods/test_at_time.py    |  1 -
 pandas/tests/groupby/methods/test_size.py     |  1 +
 pandas/tests/indexes/test_setops.py           |  5 +++++
 pandas/tests/reshape/concat/test_dataframe.py |  1 -
 pandas/tests/window/test_expanding.py         |  6 +++---
 pandas/tests/window/test_rolling.py           | 20 +++++++++----------
 7 files changed, 19 insertions(+), 34 deletions(-)

diff --git a/pandas/conftest.py b/pandas/conftest.py
index 983272d79081e..152a5efb92add 100644
--- a/pandas/conftest.py
+++ b/pandas/conftest.py
@@ -281,17 +281,6 @@ def axis(request):
     return request.param
 
 
-axis_frame = axis
-
-
-@pytest.fixture(params=[1, "columns"], ids=lambda x: f"axis={repr(x)}")
-def axis_1(request):
-    """
-    Fixture for returning aliases of axis 1 of a DataFrame.
-    """
-    return request.param
-
-
 @pytest.fixture(params=[True, False, None])
 def observed(request):
     """
@@ -674,10 +663,6 @@ def index(request):
     return indices_dict[request.param].copy()
 
 
-# Needed to generate cartesian product of indices
-index_fixture2 = index
-
-
 @pytest.fixture(
     params=[
         key for key, value in indices_dict.items() if not isinstance(value, MultiIndex)
@@ -691,10 +676,6 @@ def index_flat(request):
     return indices_dict[key].copy()
 
 
-# Alias so we can test with cartesian product of index_flat
-index_flat2 = index_flat
-
-
 @pytest.fixture(
     params=[
         key
diff --git a/pandas/tests/frame/methods/test_at_time.py b/pandas/tests/frame/methods/test_at_time.py
index 4c1434bd66aff..1ebe9920933d1 100644
--- a/pandas/tests/frame/methods/test_at_time.py
+++ b/pandas/tests/frame/methods/test_at_time.py
@@ -95,7 +95,6 @@ def test_at_time_raises(self, frame_or_series):
         with pytest.raises(TypeError, match=msg):  # index is not a DatetimeIndex
             obj.at_time("00:00")
 
-    @pytest.mark.parametrize("axis", ["index", "columns", 0, 1])
     def test_at_time_axis(self, axis):
         # issue 8839
         rng = date_range("1/1/2000", "1/5/2000", freq="5min")
diff --git a/pandas/tests/groupby/methods/test_size.py b/pandas/tests/groupby/methods/test_size.py
index 93a4e743d0d71..c4d31eb9ada59 100644
--- a/pandas/tests/groupby/methods/test_size.py
+++ b/pandas/tests/groupby/methods/test_size.py
@@ -32,6 +32,7 @@ def test_size(df, by):
         pytest.param([None, None, None, None], marks=pytest.mark.xfail),
     ],
 )
+@pytest.mark.parametrize("axis_1", [1, "columns"])
 def test_size_axis_1(df, axis_1, by, sort, dropna):
     # GH#45715
     counts = {key: sum(value == key for value in by) for key in dict.fromkeys(by)}
diff --git a/pandas/tests/indexes/test_setops.py b/pandas/tests/indexes/test_setops.py
index 4a6982cf98670..8f4dd1c64236a 100644
--- a/pandas/tests/indexes/test_setops.py
+++ b/pandas/tests/indexes/test_setops.py
@@ -56,6 +56,11 @@ def any_dtype_for_small_pos_integer_indexes(request):
     return request.param
 
 
+@pytest.fixture
+def index_flat2(index_flat):
+    return index_flat
+
+
 def test_union_same_types(index):
     # Union with a non-unique, non-monotonic index raises error
     # Only needed for bool index factory
diff --git a/pandas/tests/reshape/concat/test_dataframe.py b/pandas/tests/reshape/concat/test_dataframe.py
index f288921c25753..8aefa9262dbc5 100644
--- a/pandas/tests/reshape/concat/test_dataframe.py
+++ b/pandas/tests/reshape/concat/test_dataframe.py
@@ -194,7 +194,6 @@ def test_concat_duplicates_in_index_with_keys(self):
 
     @pytest.mark.parametrize("ignore_index", [True, False])
     @pytest.mark.parametrize("order", ["C", "F"])
-    @pytest.mark.parametrize("axis", [0, 1])
     def test_concat_copies(self, axis, order, ignore_index, using_copy_on_write):
         # based on asv ConcatDataFrames
         df = DataFrame(np.zeros((10, 5), dtype=np.float32, order=order))
diff --git a/pandas/tests/window/test_expanding.py b/pandas/tests/window/test_expanding.py
index aebb9e86c763f..e56d62e98d258 100644
--- a/pandas/tests/window/test_expanding.py
+++ b/pandas/tests/window/test_expanding.py
@@ -79,10 +79,10 @@ def test_missing_minp_zero():
     tm.assert_series_equal(result, expected)
 
 
-def test_expanding_axis(axis_frame):
+def test_expanding_axis(axis):
     # see gh-23372.
     df = DataFrame(np.ones((10, 20)))
-    axis = df._get_axis_number(axis_frame)
+    axis = df._get_axis_number(axis)
 
     if axis == 0:
         msg = "The 'axis' keyword in DataFrame.expanding is deprecated"
@@ -95,7 +95,7 @@ def test_expanding_axis(axis_frame):
         expected = DataFrame([[np.nan] * 2 + [float(i) for i in range(3, 21)]] * 10)
 
     with tm.assert_produces_warning(FutureWarning, match=msg):
-        result = df.expanding(3, axis=axis_frame).sum()
+        result = df.expanding(3, axis=axis).sum()
     tm.assert_frame_equal(result, expected)
 
 
diff --git a/pandas/tests/window/test_rolling.py b/pandas/tests/window/test_rolling.py
index f353a7fa2f0fe..e1362109c8157 100644
--- a/pandas/tests/window/test_rolling.py
+++ b/pandas/tests/window/test_rolling.py
@@ -594,10 +594,10 @@ def test_multi_index_names():
     assert result.index.names == [None, "1", "2"]
 
 
-def test_rolling_axis_sum(axis_frame):
+def test_rolling_axis_sum(axis):
     # see gh-23372.
     df = DataFrame(np.ones((10, 20)))
-    axis = df._get_axis_number(axis_frame)
+    axis = df._get_axis_number(axis)
 
     if axis == 0:
         msg = "The 'axis' keyword in DataFrame.rolling"
@@ -608,15 +608,15 @@ def test_rolling_axis_sum(axis_frame):
         expected = DataFrame([[np.nan] * 2 + [3.0] * 18] * 10)
 
     with tm.assert_produces_warning(FutureWarning, match=msg):
-        result = df.rolling(3, axis=axis_frame).sum()
+        result = df.rolling(3, axis=axis).sum()
     tm.assert_frame_equal(result, expected)
 
 
-def test_rolling_axis_count(axis_frame):
+def test_rolling_axis_count(axis):
     # see gh-26055
     df = DataFrame({"x": range(3), "y": range(3)})
 
-    axis = df._get_axis_number(axis_frame)
+    axis = df._get_axis_number(axis)
 
     if axis in [0, "index"]:
         msg = "The 'axis' keyword in DataFrame.rolling"
@@ -626,7 +626,7 @@ def test_rolling_axis_count(axis_frame):
         expected = DataFrame({"x": [1.0, 1.0, 1.0], "y": [2.0, 2.0, 2.0]})
 
     with tm.assert_produces_warning(FutureWarning, match=msg):
-        result = df.rolling(2, axis=axis_frame, min_periods=0).count()
+        result = df.rolling(2, axis=axis, min_periods=0).count()
     tm.assert_frame_equal(result, expected)
 
 
@@ -639,21 +639,21 @@ def test_readonly_array():
     tm.assert_series_equal(result, expected)
 
 
-def test_rolling_datetime(axis_frame, tz_naive_fixture):
+def test_rolling_datetime(axis, tz_naive_fixture):
     # GH-28192
     tz = tz_naive_fixture
     df = DataFrame(
         {i: [1] * 2 for i in date_range("2019-8-01", "2019-08-03", freq="D", tz=tz)}
     )
 
-    if axis_frame in [0, "index"]:
+    if axis in [0, "index"]:
         msg = "The 'axis' keyword in DataFrame.rolling"
         with tm.assert_produces_warning(FutureWarning, match=msg):
-            result = df.T.rolling("2D", axis=axis_frame).sum().T
+            result = df.T.rolling("2D", axis=axis).sum().T
     else:
         msg = "Support for axis=1 in DataFrame.rolling"
         with tm.assert_produces_warning(FutureWarning, match=msg):
-            result = df.rolling("2D", axis=axis_frame).sum()
+            result = df.rolling("2D", axis=axis).sum()
     expected = DataFrame(
         {
             **{

From ebde8a516bd0eb14bb25655dcfebd91030b791c2 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 11:44:02 -0800
Subject: [PATCH 02/26] Use top level dropna/observed fixture

---
 pandas/conftest.py                 |  8 ++++++++
 pandas/tests/groupby/conftest.py   | 10 ----------
 pandas/tests/reshape/test_pivot.py |  5 -----
 3 files changed, 8 insertions(+), 15 deletions(-)

diff --git a/pandas/conftest.py b/pandas/conftest.py
index 152a5efb92add..ac95557378dce 100644
--- a/pandas/conftest.py
+++ b/pandas/conftest.py
@@ -302,6 +302,14 @@ def ordered(request):
     return request.param
 
 
+@pytest.fixture(params=[True, False])
+def dropna(request):
+    """
+    Boolean 'dropna' parameter.
+    """
+    return request.param
+
+
 @pytest.fixture(params=[True, False])
 def skipna(request):
     """
diff --git a/pandas/tests/groupby/conftest.py b/pandas/tests/groupby/conftest.py
index dce3f072ed903..e93b7472cc286 100644
--- a/pandas/tests/groupby/conftest.py
+++ b/pandas/tests/groupby/conftest.py
@@ -23,16 +23,6 @@ def as_index(request):
     return request.param
 
 
-@pytest.fixture(params=[True, False])
-def dropna(request):
-    return request.param
-
-
-@pytest.fixture(params=[True, False])
-def observed(request):
-    return request.param
-
-
 @pytest.fixture
 def df():
     return DataFrame(
diff --git a/pandas/tests/reshape/test_pivot.py b/pandas/tests/reshape/test_pivot.py
index 18a449b4d0c67..5ca0da3991b8e 100644
--- a/pandas/tests/reshape/test_pivot.py
+++ b/pandas/tests/reshape/test_pivot.py
@@ -30,11 +30,6 @@
 from pandas.core.reshape.pivot import pivot_table
 
 
-@pytest.fixture(params=[True, False])
-def dropna(request):
-    return request.param
-
-
 @pytest.fixture(params=[([0] * 4, [1] * 4), (range(3), range(1, 4))])
 def interval_values(request, closed):
     left, right = request.param

From ff6c7ef7cb6e2d1361943b22137cc55a87f80014 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 11:46:31 -0800
Subject: [PATCH 03/26] Use top level sort fixture

---
 pandas/conftest.py                      | 8 ++++++++
 pandas/tests/groupby/conftest.py        | 5 -----
 pandas/tests/indexes/conftest.py        | 3 +--
 pandas/tests/reshape/concat/conftest.py | 7 -------
 4 files changed, 9 insertions(+), 14 deletions(-)
 delete mode 100644 pandas/tests/reshape/concat/conftest.py

diff --git a/pandas/conftest.py b/pandas/conftest.py
index ac95557378dce..51bf494361862 100644
--- a/pandas/conftest.py
+++ b/pandas/conftest.py
@@ -310,6 +310,14 @@ def dropna(request):
     return request.param
 
 
+@pytest.fixture(params=[True, False])
+def sort(request):
+    """
+    Boolean 'sort' parameter.
+    """
+    return request.param
+
+
 @pytest.fixture(params=[True, False])
 def skipna(request):
     """
diff --git a/pandas/tests/groupby/conftest.py b/pandas/tests/groupby/conftest.py
index e93b7472cc286..187076a7bac0d 100644
--- a/pandas/tests/groupby/conftest.py
+++ b/pandas/tests/groupby/conftest.py
@@ -13,11 +13,6 @@
 )
 
 
-@pytest.fixture(params=[True, False])
-def sort(request):
-    return request.param
-
-
 @pytest.fixture(params=[True, False])
 def as_index(request):
     return request.param
diff --git a/pandas/tests/indexes/conftest.py b/pandas/tests/indexes/conftest.py
index bfb7acdcf4812..61f6be000cee8 100644
--- a/pandas/tests/indexes/conftest.py
+++ b/pandas/tests/indexes/conftest.py
@@ -15,8 +15,7 @@ def sort(request):
 
     Caution:
         Don't confuse this one with the "sort" fixture used
-        for DataFrame.append or concat. That one has
-        parameters [True, False].
+        for concat. That one has parameters [True, False].
 
         We can't combine them as sort=True is not permitted
         in the Index setops methods.
diff --git a/pandas/tests/reshape/concat/conftest.py b/pandas/tests/reshape/concat/conftest.py
deleted file mode 100644
index 62b8c59ba8855..0000000000000
--- a/pandas/tests/reshape/concat/conftest.py
+++ /dev/null
@@ -1,7 +0,0 @@
-import pytest
-
-
-@pytest.fixture(params=[True, False])
-def sort(request):
-    """Boolean sort keyword for concat and DataFrame.append."""
-    return request.param

From 3b4f3ecaa4e8b9390dbdd3e2c9747098de3da9d4 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 11:49:52 -0800
Subject: [PATCH 04/26] Use top level sort fixture

---
 pandas/tests/frame/methods/test_join.py           | 4 ++--
 pandas/tests/frame/test_stack_unstack.py          | 1 -
 pandas/tests/groupby/methods/test_size.py         | 1 -
 pandas/tests/groupby/methods/test_value_counts.py | 2 --
 pandas/tests/groupby/test_categorical.py          | 1 -
 pandas/tests/groupby/test_grouping.py             | 2 --
 pandas/tests/groupby/test_reductions.py           | 3 ---
 pandas/tests/reshape/merge/test_merge.py          | 1 -
 pandas/tests/reshape/merge/test_multi.py          | 2 --
 pandas/tests/test_algos.py                        | 4 ----
 pandas/tests/test_sorting.py                      | 1 -
 11 files changed, 2 insertions(+), 20 deletions(-)

diff --git a/pandas/tests/frame/methods/test_join.py b/pandas/tests/frame/methods/test_join.py
index 735f6c50ab739..02f0b9e20871d 100644
--- a/pandas/tests/frame/methods/test_join.py
+++ b/pandas/tests/frame/methods/test_join.py
@@ -391,8 +391,8 @@ def test_join_list_series(float_frame):
     tm.assert_frame_equal(result, float_frame)
 
 
-@pytest.mark.parametrize("sort_kw", [True, False])
-def test_suppress_future_warning_with_sort_kw(sort_kw):
+def test_suppress_future_warning_with_sort_kw(sort):
+    sort_kw = sort
     a = DataFrame({"col1": [1, 2]}, index=["c", "a"])
 
     b = DataFrame({"col2": [4, 5]}, index=["b", "a"])
diff --git a/pandas/tests/frame/test_stack_unstack.py b/pandas/tests/frame/test_stack_unstack.py
index 554a9d4ce2d5d..06cc440840e51 100644
--- a/pandas/tests/frame/test_stack_unstack.py
+++ b/pandas/tests/frame/test_stack_unstack.py
@@ -2207,7 +2207,6 @@ def __init__(self, *args, **kwargs) -> None:
         ),
     )
     @pytest.mark.parametrize("stack_lev", range(2))
-    @pytest.mark.parametrize("sort", [True, False])
     def test_stack_order_with_unsorted_levels(
         self, levels, stack_lev, sort, future_stack
     ):
diff --git a/pandas/tests/groupby/methods/test_size.py b/pandas/tests/groupby/methods/test_size.py
index c4d31eb9ada59..92a277d8014d4 100644
--- a/pandas/tests/groupby/methods/test_size.py
+++ b/pandas/tests/groupby/methods/test_size.py
@@ -52,7 +52,6 @@ def test_size_axis_1(df, axis_1, by, sort, dropna):
 
 
 @pytest.mark.parametrize("by", ["A", "B", ["A", "B"]])
-@pytest.mark.parametrize("sort", [True, False])
 def test_size_sort(sort, by):
     df = DataFrame(np.random.default_rng(2).choice(20, (1000, 3)), columns=list("ABC"))
     left = df.groupby(by=by, sort=sort).size()
diff --git a/pandas/tests/groupby/methods/test_value_counts.py b/pandas/tests/groupby/methods/test_value_counts.py
index 2fa79c815d282..538ed7f93f857 100644
--- a/pandas/tests/groupby/methods/test_value_counts.py
+++ b/pandas/tests/groupby/methods/test_value_counts.py
@@ -76,9 +76,7 @@ def seed_df(seed_nans, n, m):
 @pytest.mark.parametrize("bins", [None, [0, 5]], ids=repr)
 @pytest.mark.parametrize("isort", [True, False])
 @pytest.mark.parametrize("normalize, name", [(True, "proportion"), (False, "count")])
-@pytest.mark.parametrize("sort", [True, False])
 @pytest.mark.parametrize("ascending", [True, False])
-@pytest.mark.parametrize("dropna", [True, False])
 def test_series_groupby_value_counts(
     seed_nans,
     num_rows,
diff --git a/pandas/tests/groupby/test_categorical.py b/pandas/tests/groupby/test_categorical.py
index 7a91601bf688f..a2cc7fd782396 100644
--- a/pandas/tests/groupby/test_categorical.py
+++ b/pandas/tests/groupby/test_categorical.py
@@ -618,7 +618,6 @@ def test_dataframe_categorical_with_nan(observed):
 
 @pytest.mark.parametrize("ordered", [True, False])
 @pytest.mark.parametrize("observed", [True, False])
-@pytest.mark.parametrize("sort", [True, False])
 def test_dataframe_categorical_ordered_observed_sort(ordered, observed, sort):
     # GH 25871: Fix groupby sorting on ordered Categoricals
     # GH 25167: Groupby with observed=True doesn't sort
diff --git a/pandas/tests/groupby/test_grouping.py b/pandas/tests/groupby/test_grouping.py
index 363ff883385db..782bb7eb7984e 100644
--- a/pandas/tests/groupby/test_grouping.py
+++ b/pandas/tests/groupby/test_grouping.py
@@ -649,7 +649,6 @@ def test_groupby_multiindex_partial_indexing_equivalence(self):
         result_groups = df.groupby([("a", 1)])["b"].groups
         tm.assert_dict_equal(expected_groups, result_groups)
 
-    @pytest.mark.parametrize("sort", [True, False])
     def test_groupby_level(self, sort, multiindex_dataframe_random_data, df):
         # GH 17537
         frame = multiindex_dataframe_random_data
@@ -708,7 +707,6 @@ def test_groupby_level_index_names(self, axis):
             with tm.assert_produces_warning(FutureWarning, match=depr_msg):
                 df.groupby(level="foo", axis=axis)
 
-    @pytest.mark.parametrize("sort", [True, False])
     def test_groupby_level_with_nas(self, sort):
         # GH 17537
         index = MultiIndex(
diff --git a/pandas/tests/groupby/test_reductions.py b/pandas/tests/groupby/test_reductions.py
index 425079f943aba..18d59cd3cd593 100644
--- a/pandas/tests/groupby/test_reductions.py
+++ b/pandas/tests/groupby/test_reductions.py
@@ -639,8 +639,6 @@ def test_max_nan_bug():
 
 
 @pytest.mark.slow
-@pytest.mark.parametrize("sort", [False, True])
-@pytest.mark.parametrize("dropna", [False, True])
 @pytest.mark.parametrize("as_index", [True, False])
 @pytest.mark.parametrize("with_nan", [True, False])
 @pytest.mark.parametrize("keys", [["joe"], ["joe", "jim"]])
@@ -1026,7 +1024,6 @@ def test_apply_to_nullable_integer_returns_float(values, function):
 )
 @pytest.mark.parametrize("axis", [0, 1])
 @pytest.mark.parametrize("skipna", [True, False])
-@pytest.mark.parametrize("sort", [True, False])
 def test_regression_allowlist_methods(op, axis, skipna, sort):
     # GH6944
     # GH 17537
diff --git a/pandas/tests/reshape/merge/test_merge.py b/pandas/tests/reshape/merge/test_merge.py
index d7a343ae9f152..3c0965308f8b7 100644
--- a/pandas/tests/reshape/merge/test_merge.py
+++ b/pandas/tests/reshape/merge/test_merge.py
@@ -2860,7 +2860,6 @@ def test_merge_multiindex_single_level():
 
 
 @pytest.mark.parametrize("how", ["left", "right", "inner", "outer"])
-@pytest.mark.parametrize("sort", [True, False])
 @pytest.mark.parametrize("on_index", [True, False])
 @pytest.mark.parametrize("left_unique", [True, False])
 @pytest.mark.parametrize("left_monotonic", [True, False])
diff --git a/pandas/tests/reshape/merge/test_multi.py b/pandas/tests/reshape/merge/test_multi.py
index 269d3a2b7078e..bc02da0d5b97b 100644
--- a/pandas/tests/reshape/merge/test_multi.py
+++ b/pandas/tests/reshape/merge/test_multi.py
@@ -88,7 +88,6 @@ def test_merge_on_multikey(self, left, right, join_type):
 
         tm.assert_frame_equal(result, expected)
 
-    @pytest.mark.parametrize("sort", [False, True])
     def test_left_join_multi_index(self, sort):
         icols = ["1st", "2nd", "3rd"]
 
@@ -150,7 +149,6 @@ def run_asserts(left, right, sort):
 
         run_asserts(left, right, sort)
 
-    @pytest.mark.parametrize("sort", [False, True])
     def test_merge_right_vs_left(self, left, right, sort):
         # compare left vs right merge with multikey
         on_cols = ["key1", "key2"]
diff --git a/pandas/tests/test_algos.py b/pandas/tests/test_algos.py
index 718d1b3ee2e83..16d684b72e1e3 100644
--- a/pandas/tests/test_algos.py
+++ b/pandas/tests/test_algos.py
@@ -63,7 +63,6 @@ def test_factorize_complex(self):
         expected_uniques = np.array([(1 + 0j), (2 + 0j), (2 + 1j)], dtype=object)
         tm.assert_numpy_array_equal(uniques, expected_uniques)
 
-    @pytest.mark.parametrize("sort", [True, False])
     def test_factorize(self, index_or_series_obj, sort):
         obj = index_or_series_obj
         result_codes, result_uniques = obj.factorize(sort=sort)
@@ -354,7 +353,6 @@ def test_datetime64_factorize(self, writable):
         tm.assert_numpy_array_equal(codes, expected_codes)
         tm.assert_numpy_array_equal(uniques, expected_uniques)
 
-    @pytest.mark.parametrize("sort", [True, False])
     def test_factorize_rangeindex(self, sort):
         # increasing -> sort doesn't matter
         ri = pd.RangeIndex.from_range(range(10))
@@ -368,7 +366,6 @@ def test_factorize_rangeindex(self, sort):
         tm.assert_numpy_array_equal(result[0], expected[0])
         tm.assert_index_equal(result[1], expected[1], exact=True)
 
-    @pytest.mark.parametrize("sort", [True, False])
     def test_factorize_rangeindex_decreasing(self, sort):
         # decreasing -> sort matters
         ri = pd.RangeIndex.from_range(range(10))
@@ -431,7 +428,6 @@ def test_parametrized_factorize_na_value(self, data, na_value):
         tm.assert_numpy_array_equal(codes, expected_codes)
         tm.assert_numpy_array_equal(uniques, expected_uniques)
 
-    @pytest.mark.parametrize("sort", [True, False])
     @pytest.mark.parametrize(
         "data, uniques",
         [
diff --git a/pandas/tests/test_sorting.py b/pandas/tests/test_sorting.py
index 285f240028152..e692d8326c5ba 100644
--- a/pandas/tests/test_sorting.py
+++ b/pandas/tests/test_sorting.py
@@ -240,7 +240,6 @@ def test_int64_overflow_sort_false_order(self, left_right):
 
     @pytest.mark.slow
     @pytest.mark.parametrize("how", ["left", "right", "outer", "inner"])
-    @pytest.mark.parametrize("sort", [True, False])
     def test_int64_overflow_one_to_many_none_match(self, how, sort):
         # one-2-many/none match
         low, high, n = -1 << 10, 1 << 10, 1 << 11

From dc01991a6ac728ae69e4e93639acd5ca93b13fa9 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 11:55:06 -0800
Subject: [PATCH 05/26] Use top level skipna fixture

---
 pandas/tests/arrays/categorical/test_analytics.py | 2 --
 pandas/tests/arrays/datetimes/test_reductions.py  | 3 ---
 pandas/tests/arrays/floating/test_function.py     | 3 ---
 pandas/tests/arrays/integer/test_function.py      | 3 ---
 pandas/tests/arrays/period/test_reductions.py     | 3 ---
 pandas/tests/arrays/string_/test_string.py        | 3 ---
 pandas/tests/arrays/timedeltas/test_reductions.py | 2 --
 pandas/tests/dtypes/test_inference.py             | 6 ------
 pandas/tests/extension/base/accumulate.py         | 1 -
 pandas/tests/extension/base/dtype.py              | 1 -
 pandas/tests/extension/base/reduce.py             | 3 ---
 pandas/tests/extension/test_arrow.py              | 5 -----
 pandas/tests/extension/test_datetime.py           | 1 -
 pandas/tests/extension/test_numpy.py              | 1 -
 pandas/tests/extension/test_sparse.py             | 2 --
 pandas/tests/frame/test_reductions.py             | 3 ---
 pandas/tests/groupby/test_reductions.py           | 1 -
 pandas/tests/reductions/test_reductions.py        | 5 -----
 pandas/tests/series/test_reductions.py            | 1 -
 19 files changed, 49 deletions(-)

diff --git a/pandas/tests/arrays/categorical/test_analytics.py b/pandas/tests/arrays/categorical/test_analytics.py
index c2c53fbc4637e..1021b18f4ae71 100644
--- a/pandas/tests/arrays/categorical/test_analytics.py
+++ b/pandas/tests/arrays/categorical/test_analytics.py
@@ -97,7 +97,6 @@ def test_min_max_ordered_empty(self, categories, expected, aggregation):
         "values, categories",
         [(["a", "b", "c", np.nan], list("cba")), ([1, 2, 3, np.nan], [3, 2, 1])],
     )
-    @pytest.mark.parametrize("skipna", [True, False])
     @pytest.mark.parametrize("function", ["min", "max"])
     def test_min_max_with_nan(self, values, categories, function, skipna):
         # GH 25303
@@ -111,7 +110,6 @@ def test_min_max_with_nan(self, values, categories, function, skipna):
             assert result == expected
 
     @pytest.mark.parametrize("function", ["min", "max"])
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_min_max_only_nan(self, function, skipna):
         # https://github.com/pandas-dev/pandas/issues/33450
         cat = Categorical([np.nan], categories=[1, 2], ordered=True)
diff --git a/pandas/tests/arrays/datetimes/test_reductions.py b/pandas/tests/arrays/datetimes/test_reductions.py
index a941546b13a56..7d83fe6ffac7d 100644
--- a/pandas/tests/arrays/datetimes/test_reductions.py
+++ b/pandas/tests/arrays/datetimes/test_reductions.py
@@ -54,7 +54,6 @@ def test_min_max(self, arr1d, unit):
         assert result is NaT
 
     @pytest.mark.parametrize("tz", [None, "US/Central"])
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_min_max_empty(self, skipna, tz):
         dtype = DatetimeTZDtype(tz=tz) if tz is not None else np.dtype("M8[ns]")
         arr = DatetimeArray._from_sequence([], dtype=dtype)
@@ -65,7 +64,6 @@ def test_min_max_empty(self, skipna, tz):
         assert result is NaT
 
     @pytest.mark.parametrize("tz", [None, "US/Central"])
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_median_empty(self, skipna, tz):
         dtype = DatetimeTZDtype(tz=tz) if tz is not None else np.dtype("M8[ns]")
         arr = DatetimeArray._from_sequence([], dtype=dtype)
@@ -164,7 +162,6 @@ def test_mean_2d(self):
         expected = dti.mean()
         assert result == expected
 
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_mean_empty(self, arr1d, skipna):
         arr = arr1d[:0]
 
diff --git a/pandas/tests/arrays/floating/test_function.py b/pandas/tests/arrays/floating/test_function.py
index 40fd66fd049a6..9ea48bfb2413f 100644
--- a/pandas/tests/arrays/floating/test_function.py
+++ b/pandas/tests/arrays/floating/test_function.py
@@ -127,7 +127,6 @@ def test_value_counts_with_normalize():
     tm.assert_series_equal(result, expected)
 
 
-@pytest.mark.parametrize("skipna", [True, False])
 @pytest.mark.parametrize("min_count", [0, 4])
 def test_floating_array_sum(skipna, min_count, dtype):
     arr = pd.array([1, 2, 3, None], dtype=dtype)
@@ -171,7 +170,6 @@ def test_preserve_dtypes(op):
     tm.assert_frame_equal(result, expected)
 
 
-@pytest.mark.parametrize("skipna", [True, False])
 @pytest.mark.parametrize("method", ["min", "max"])
 def test_floating_array_min_max(skipna, method, dtype):
     arr = pd.array([0.0, 1.0, None], dtype=dtype)
@@ -183,7 +181,6 @@ def test_floating_array_min_max(skipna, method, dtype):
         assert result is pd.NA
 
 
-@pytest.mark.parametrize("skipna", [True, False])
 @pytest.mark.parametrize("min_count", [0, 9])
 def test_floating_array_prod(skipna, min_count, dtype):
     arr = pd.array([1.0, 2.0, None], dtype=dtype)
diff --git a/pandas/tests/arrays/integer/test_function.py b/pandas/tests/arrays/integer/test_function.py
index d48b636a98feb..33300fff925f6 100644
--- a/pandas/tests/arrays/integer/test_function.py
+++ b/pandas/tests/arrays/integer/test_function.py
@@ -141,7 +141,6 @@ def test_value_counts_with_normalize():
     tm.assert_series_equal(result, expected)
 
 
-@pytest.mark.parametrize("skipna", [True, False])
 @pytest.mark.parametrize("min_count", [0, 4])
 def test_integer_array_sum(skipna, min_count, any_int_ea_dtype):
     dtype = any_int_ea_dtype
@@ -153,7 +152,6 @@ def test_integer_array_sum(skipna, min_count, any_int_ea_dtype):
         assert result is pd.NA
 
 
-@pytest.mark.parametrize("skipna", [True, False])
 @pytest.mark.parametrize("method", ["min", "max"])
 def test_integer_array_min_max(skipna, method, any_int_ea_dtype):
     dtype = any_int_ea_dtype
@@ -166,7 +164,6 @@ def test_integer_array_min_max(skipna, method, any_int_ea_dtype):
         assert result is pd.NA
 
 
-@pytest.mark.parametrize("skipna", [True, False])
 @pytest.mark.parametrize("min_count", [0, 9])
 def test_integer_array_prod(skipna, min_count, any_int_ea_dtype):
     dtype = any_int_ea_dtype
diff --git a/pandas/tests/arrays/period/test_reductions.py b/pandas/tests/arrays/period/test_reductions.py
index 2889cc786dd71..5b859d86eb6d0 100644
--- a/pandas/tests/arrays/period/test_reductions.py
+++ b/pandas/tests/arrays/period/test_reductions.py
@@ -1,5 +1,3 @@
-import pytest
-
 import pandas as pd
 from pandas.core.arrays import period_array
 
@@ -32,7 +30,6 @@ def test_min_max(self):
         result = arr.max(skipna=False)
         assert result is pd.NaT
 
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_min_max_empty(self, skipna):
         arr = period_array([], freq="D")
         result = arr.min(skipna=skipna)
diff --git a/pandas/tests/arrays/string_/test_string.py b/pandas/tests/arrays/string_/test_string.py
index 41255b2516e7e..66bd0f3f40083 100644
--- a/pandas/tests/arrays/string_/test_string.py
+++ b/pandas/tests/arrays/string_/test_string.py
@@ -415,7 +415,6 @@ def test_astype_float(dtype, any_float_dtype):
     tm.assert_series_equal(result, expected)
 
 
-@pytest.mark.parametrize("skipna", [True, False])
 @pytest.mark.xfail(reason="Not implemented StringArray.sum")
 def test_reduce(skipna, dtype):
     arr = pd.Series(["a", "b", "c"], dtype=dtype)
@@ -423,7 +422,6 @@ def test_reduce(skipna, dtype):
     assert result == "abc"
 
 
-@pytest.mark.parametrize("skipna", [True, False])
 @pytest.mark.xfail(reason="Not implemented StringArray.sum")
 def test_reduce_missing(skipna, dtype):
     arr = pd.Series([None, "a", None, "b", "c", None], dtype=dtype)
@@ -435,7 +433,6 @@ def test_reduce_missing(skipna, dtype):
 
 
 @pytest.mark.parametrize("method", ["min", "max"])
-@pytest.mark.parametrize("skipna", [True, False])
 def test_min_max(method, skipna, dtype):
     arr = pd.Series(["a", "b", "c", None], dtype=dtype)
     result = getattr(arr, method)(skipna=skipna)
diff --git a/pandas/tests/arrays/timedeltas/test_reductions.py b/pandas/tests/arrays/timedeltas/test_reductions.py
index f1d2cc6a90519..d9d81e886efc4 100644
--- a/pandas/tests/arrays/timedeltas/test_reductions.py
+++ b/pandas/tests/arrays/timedeltas/test_reductions.py
@@ -10,7 +10,6 @@
 
 class TestReductions:
     @pytest.mark.parametrize("name", ["std", "min", "max", "median", "mean"])
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_reductions_empty(self, name, skipna):
         tdi = pd.TimedeltaIndex([])
         arr = tdi.array
@@ -21,7 +20,6 @@ def test_reductions_empty(self, name, skipna):
         result = getattr(arr, name)(skipna=skipna)
         assert result is pd.NaT
 
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_sum_empty(self, skipna):
         tdi = pd.TimedeltaIndex([])
         arr = tdi.array
diff --git a/pandas/tests/dtypes/test_inference.py b/pandas/tests/dtypes/test_inference.py
index ff2cfc1278331..82db41de27117 100644
--- a/pandas/tests/dtypes/test_inference.py
+++ b/pandas/tests/dtypes/test_inference.py
@@ -1050,7 +1050,6 @@ def test_inferred_dtype_fixture(self, any_skipna_inferred_dtype):
         # make sure the inferred dtype of the fixture is as requested
         assert inferred_dtype == lib.infer_dtype(values, skipna=True)
 
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_length_zero(self, skipna):
         result = lib.infer_dtype(np.array([], dtype="i4"), skipna=skipna)
         assert result == "integer"
@@ -1162,7 +1161,6 @@ def test_decimals(self):
         assert result == "decimal"
 
     # complex is compatible with nan, so skipna has no effect
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_complex(self, skipna):
         # gets cast to complex on array construction
         arr = np.array([1.0, 2.0, 1 + 1j])
@@ -1342,7 +1340,6 @@ def test_infer_dtype_period(self):
         assert lib.infer_dtype(arr, skipna=True) == "mixed"
 
     @pytest.mark.parametrize("klass", [pd.array, Series, Index])
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_infer_dtype_period_array(self, klass, skipna):
         # https://github.com/pandas-dev/pandas/issues/23553
         values = klass(
@@ -1532,7 +1529,6 @@ def test_date(self):
             [pd.NaT, date(2020, 1, 1)],
         ],
     )
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_infer_dtype_date_order_invariant(self, values, skipna):
         # https://github.com/pandas-dev/pandas/issues/33741
         result = lib.infer_dtype(values, skipna=skipna)
@@ -1704,7 +1700,6 @@ def test_interval_mismatched_subtype(self):
         assert lib.infer_dtype(arr, skipna=False) == "interval"
 
     @pytest.mark.parametrize("klass", [pd.array, Series])
-    @pytest.mark.parametrize("skipna", [True, False])
     @pytest.mark.parametrize("data", [["a", "b", "c"], ["a", "b", pd.NA]])
     def test_string_dtype(self, data, skipna, klass, nullable_string_dtype):
         # StringArray
@@ -1713,7 +1708,6 @@ def test_string_dtype(self, data, skipna, klass, nullable_string_dtype):
         assert inferred == "string"
 
     @pytest.mark.parametrize("klass", [pd.array, Series])
-    @pytest.mark.parametrize("skipna", [True, False])
     @pytest.mark.parametrize("data", [[True, False, True], [True, False, pd.NA]])
     def test_boolean_dtype(self, data, skipna, klass):
         # BooleanArray
diff --git a/pandas/tests/extension/base/accumulate.py b/pandas/tests/extension/base/accumulate.py
index 9a41a3a582c4a..9189ef7ec9aa5 100644
--- a/pandas/tests/extension/base/accumulate.py
+++ b/pandas/tests/extension/base/accumulate.py
@@ -26,7 +26,6 @@ def check_accumulate(self, ser: pd.Series, op_name: str, skipna: bool):
         expected = getattr(alt, op_name)(skipna=skipna)
         tm.assert_series_equal(result, expected, check_dtype=False)
 
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_accumulate_series(self, data, all_numeric_accumulations, skipna):
         op_name = all_numeric_accumulations
         ser = pd.Series(data)
diff --git a/pandas/tests/extension/base/dtype.py b/pandas/tests/extension/base/dtype.py
index c7b768f6e3c88..3fb116430861a 100644
--- a/pandas/tests/extension/base/dtype.py
+++ b/pandas/tests/extension/base/dtype.py
@@ -114,7 +114,6 @@ def test_get_common_dtype(self, dtype):
         # only case we can test in general)
         assert dtype._get_common_dtype([dtype]) == dtype
 
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_infer_dtype(self, data, data_missing, skipna):
         # only testing that this works without raising an error
         res = infer_dtype(data, skipna=skipna)
diff --git a/pandas/tests/extension/base/reduce.py b/pandas/tests/extension/base/reduce.py
index 6ea1b3a6fbe9d..2a443901fa41a 100644
--- a/pandas/tests/extension/base/reduce.py
+++ b/pandas/tests/extension/base/reduce.py
@@ -77,7 +77,6 @@ def check_reduce_frame(self, ser: pd.Series, op_name: str, skipna: bool):
 
         tm.assert_extension_array_equal(result1, expected)
 
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_reduce_series_boolean(self, data, all_boolean_reductions, skipna):
         op_name = all_boolean_reductions
         ser = pd.Series(data)
@@ -96,7 +95,6 @@ def test_reduce_series_boolean(self, data, all_boolean_reductions, skipna):
             self.check_reduce(ser, op_name, skipna)
 
     @pytest.mark.filterwarnings("ignore::RuntimeWarning")
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_reduce_series_numeric(self, data, all_numeric_reductions, skipna):
         op_name = all_numeric_reductions
         ser = pd.Series(data)
@@ -115,7 +113,6 @@ def test_reduce_series_numeric(self, data, all_numeric_reductions, skipna):
             # min/max with empty produce numpy warnings
             self.check_reduce(ser, op_name, skipna)
 
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_reduce_frame(self, data, all_numeric_reductions, skipna):
         op_name = all_numeric_reductions
         ser = pd.Series(data)
diff --git a/pandas/tests/extension/test_arrow.py b/pandas/tests/extension/test_arrow.py
index 674a5da216011..d4a4bc8bb8bd3 100644
--- a/pandas/tests/extension/test_arrow.py
+++ b/pandas/tests/extension/test_arrow.py
@@ -418,7 +418,6 @@ def _supports_accumulation(self, ser: pd.Series, op_name: str) -> bool:
                 return False
         return True
 
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_accumulate_series(self, data, all_numeric_accumulations, skipna, request):
         pa_type = data.dtype.pyarrow_dtype
         op_name = all_numeric_accumulations
@@ -520,7 +519,6 @@ def check_reduce(self, ser: pd.Series, op_name: str, skipna: bool):
             expected = getattr(alt, op_name)(skipna=skipna)
         tm.assert_almost_equal(result, expected)
 
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_reduce_series_numeric(self, data, all_numeric_reductions, skipna, request):
         dtype = data.dtype
         pa_dtype = dtype.pyarrow_dtype
@@ -546,7 +544,6 @@ def test_reduce_series_numeric(self, data, all_numeric_reductions, skipna, reque
             request.applymarker(xfail_mark)
         super().test_reduce_series_numeric(data, all_numeric_reductions, skipna)
 
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_reduce_series_boolean(
         self, data, all_boolean_reductions, skipna, na_value, request
     ):
@@ -583,7 +580,6 @@ def _get_expected_reduction_dtype(self, arr, op_name: str, skipna: bool):
             }[arr.dtype.kind]
         return cmp_dtype
 
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_reduce_frame(self, data, all_numeric_reductions, skipna, request):
         op_name = all_numeric_reductions
         if op_name == "skew":
@@ -2703,7 +2699,6 @@ def test_dt_tz_convert(unit):
     tm.assert_series_equal(result, expected)
 
 
-@pytest.mark.parametrize("skipna", [True, False])
 def test_boolean_reduce_series_all_null(all_boolean_reductions, skipna):
     # GH51624
     ser = pd.Series([None], dtype="float64[pyarrow]")
diff --git a/pandas/tests/extension/test_datetime.py b/pandas/tests/extension/test_datetime.py
index efb88dc7bd4e1..a60ece09dc73e 100644
--- a/pandas/tests/extension/test_datetime.py
+++ b/pandas/tests/extension/test_datetime.py
@@ -94,7 +94,6 @@ def _supports_accumulation(self, ser, op_name: str) -> bool:
     def _supports_reduction(self, obj, op_name: str) -> bool:
         return op_name in ["min", "max", "median", "mean", "std", "any", "all"]
 
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_reduce_series_boolean(self, data, all_boolean_reductions, skipna):
         meth = all_boolean_reductions
         msg = f"'{meth}' with datetime64 dtypes is deprecated and will raise in"
diff --git a/pandas/tests/extension/test_numpy.py b/pandas/tests/extension/test_numpy.py
index aaf49f53ba02b..8bf16272dd8c5 100644
--- a/pandas/tests/extension/test_numpy.py
+++ b/pandas/tests/extension/test_numpy.py
@@ -313,7 +313,6 @@ def check_reduce(self, ser: pd.Series, op_name: str, skipna: bool):
         tm.assert_almost_equal(result, expected)
 
     @pytest.mark.skip("TODO: tests not written yet")
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_reduce_frame(self, data, all_numeric_reductions, skipna):
         pass
 
diff --git a/pandas/tests/extension/test_sparse.py b/pandas/tests/extension/test_sparse.py
index 4039a5d01f372..4c6550ff191a5 100644
--- a/pandas/tests/extension/test_sparse.py
+++ b/pandas/tests/extension/test_sparse.py
@@ -102,7 +102,6 @@ class TestSparseArray(base.ExtensionTests):
     def _supports_reduction(self, obj, op_name: str) -> bool:
         return True
 
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_reduce_series_numeric(self, data, all_numeric_reductions, skipna, request):
         if all_numeric_reductions in [
             "prod",
@@ -127,7 +126,6 @@ def test_reduce_series_numeric(self, data, all_numeric_reductions, skipna, reque
 
         super().test_reduce_series_numeric(data, all_numeric_reductions, skipna)
 
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_reduce_frame(self, data, all_numeric_reductions, skipna, request):
         if all_numeric_reductions in [
             "prod",
diff --git a/pandas/tests/frame/test_reductions.py b/pandas/tests/frame/test_reductions.py
index 66145c32c18d7..1ef863c02c35e 100644
--- a/pandas/tests/frame/test_reductions.py
+++ b/pandas/tests/frame/test_reductions.py
@@ -1068,7 +1068,6 @@ def test_sum_bools(self):
     # ----------------------------------------------------------------------
     # Index of max / min
 
-    @pytest.mark.parametrize("skipna", [True, False])
     @pytest.mark.parametrize("axis", [0, 1])
     def test_idxmin(self, float_frame, int_frame, skipna, axis):
         frame = float_frame
@@ -1117,7 +1116,6 @@ def test_idxmin_axis_2(self, float_frame):
         with pytest.raises(ValueError, match=msg):
             frame.idxmin(axis=2)
 
-    @pytest.mark.parametrize("skipna", [True, False])
     @pytest.mark.parametrize("axis", [0, 1])
     def test_idxmax(self, float_frame, int_frame, skipna, axis):
         frame = float_frame
@@ -1361,7 +1359,6 @@ def test_any_all_extra(self):
 
     @pytest.mark.parametrize("axis", [0, 1])
     @pytest.mark.parametrize("bool_agg_func", ["any", "all"])
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_any_all_object_dtype(
         self, axis, bool_agg_func, skipna, using_infer_string
     ):
diff --git a/pandas/tests/groupby/test_reductions.py b/pandas/tests/groupby/test_reductions.py
index 18d59cd3cd593..c8678156d0c75 100644
--- a/pandas/tests/groupby/test_reductions.py
+++ b/pandas/tests/groupby/test_reductions.py
@@ -1023,7 +1023,6 @@ def test_apply_to_nullable_integer_returns_float(values, function):
     ],
 )
 @pytest.mark.parametrize("axis", [0, 1])
-@pytest.mark.parametrize("skipna", [True, False])
 def test_regression_allowlist_methods(op, axis, skipna, sort):
     # GH6944
     # GH 17537
diff --git a/pandas/tests/reductions/test_reductions.py b/pandas/tests/reductions/test_reductions.py
index 30ec0d0affaa3..27a802d14c23e 100644
--- a/pandas/tests/reductions/test_reductions.py
+++ b/pandas/tests/reductions/test_reductions.py
@@ -802,7 +802,6 @@ def test_var_masked_array(self, ddof, exp):
         assert result == exp
 
     @pytest.mark.parametrize("dtype", ("m8[ns]", "m8[ns]", "M8[ns]", "M8[ns, UTC]"))
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_empty_timeseries_reductions_return_nat(self, dtype, skipna):
         # covers GH#11245
         assert Series([], dtype=dtype).min(skipna=skipna) is NaT
@@ -987,7 +986,6 @@ def test_all_any_bool_only(self):
         assert not s.all(bool_only=True)
 
     @pytest.mark.parametrize("bool_agg_func", ["any", "all"])
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_any_all_object_dtype(self, bool_agg_func, skipna):
         # GH#12863
         ser = Series(["a", "b", "c", "d", "e"], dtype=object)
@@ -1011,7 +1009,6 @@ def test_any_all_object_dtype_missing(self, data, bool_agg_func):
 
     @pytest.mark.parametrize("dtype", ["boolean", "Int64", "UInt64", "Float64"])
     @pytest.mark.parametrize("bool_agg_func", ["any", "all"])
-    @pytest.mark.parametrize("skipna", [True, False])
     @pytest.mark.parametrize(
         # expected_data indexed as [[skipna=False/any, skipna=False/all],
         #                           [skipna=True/any, skipna=True/all]]
@@ -1380,7 +1377,6 @@ def test_min_max_ordered(self, values, categories, function):
         assert result == expected
 
     @pytest.mark.parametrize("function", ["min", "max"])
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_min_max_ordered_with_nan_only(self, function, skipna):
         # https://github.com/pandas-dev/pandas/issues/33450
         cat = Series(Categorical([np.nan], categories=[1, 2], ordered=True))
@@ -1388,7 +1384,6 @@ def test_min_max_ordered_with_nan_only(self, function, skipna):
         assert result is np.nan
 
     @pytest.mark.parametrize("function", ["min", "max"])
-    @pytest.mark.parametrize("skipna", [True, False])
     def test_min_max_skipna(self, function, skipna):
         cat = Series(
             Categorical(["a", "b", np.nan, "a"], categories=["b", "a"], ordered=True)
diff --git a/pandas/tests/series/test_reductions.py b/pandas/tests/series/test_reductions.py
index 76353ab25fca6..0f8627d46067e 100644
--- a/pandas/tests/series/test_reductions.py
+++ b/pandas/tests/series/test_reductions.py
@@ -70,7 +70,6 @@ def test_reductions_td64_with_nat():
     assert ser.max() == exp
 
 
-@pytest.mark.parametrize("skipna", [True, False])
 def test_td64_sum_empty(skipna):
     # GH#37151
     ser = Series([], dtype="timedelta64[ns]")

From 4a3cb1372294c15897f3165bf4d997897cab5637 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 11:55:57 -0800
Subject: [PATCH 06/26] Use top level keep fixture

---
 pandas/tests/extension/base/methods.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/pandas/tests/extension/base/methods.py b/pandas/tests/extension/base/methods.py
index c803a8113b4a4..88ef67605de98 100644
--- a/pandas/tests/extension/base/methods.py
+++ b/pandas/tests/extension/base/methods.py
@@ -248,7 +248,6 @@ def test_sort_values_frame(self, data_for_sorting, ascending):
         )
         tm.assert_frame_equal(result, expected)
 
-    @pytest.mark.parametrize("keep", ["first", "last", False])
     def test_duplicated(self, data, keep):
         arr = data.take([0, 1, 0, 1])
         result = arr.duplicated(keep=keep)

From c9e3a57c1f8adc33a827e1f8f5e22110acc558e8 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 11:57:35 -0800
Subject: [PATCH 07/26] Use top level closed fixture

---
 pandas/tests/indexes/interval/test_pickle.py | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/pandas/tests/indexes/interval/test_pickle.py b/pandas/tests/indexes/interval/test_pickle.py
index 308a90e72eab5..c52106e5f0786 100644
--- a/pandas/tests/indexes/interval/test_pickle.py
+++ b/pandas/tests/indexes/interval/test_pickle.py
@@ -1,11 +1,8 @@
-import pytest
-
 from pandas import IntervalIndex
 import pandas._testing as tm
 
 
 class TestPickle:
-    @pytest.mark.parametrize("closed", ["left", "right", "both"])
     def test_pickle_round_trip_closed(self, closed):
         # https://github.com/pandas-dev/pandas/issues/35658
         idx = IntervalIndex.from_tuples([(1, 2), (2, 3)], closed=closed)

From 84ef346196aba82a008b696d2e48c16b2a318c2e Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 12:03:26 -0800
Subject: [PATCH 08/26] Use top level writable fixture

---
 pandas/tests/libs/test_join.py          | 10 ++++------
 pandas/tests/tools/test_to_datetime.py  |  6 ++----
 pandas/tests/tools/test_to_timedelta.py |  6 ++----
 3 files changed, 8 insertions(+), 14 deletions(-)

diff --git a/pandas/tests/libs/test_join.py b/pandas/tests/libs/test_join.py
index ba2e6e7130929..bf8b4fabc54cb 100644
--- a/pandas/tests/libs/test_join.py
+++ b/pandas/tests/libs/test_join.py
@@ -138,14 +138,12 @@ def test_cython_inner_join(self):
         tm.assert_numpy_array_equal(rs, exp_rs)
 
 
-@pytest.mark.parametrize("readonly", [True, False])
-def test_left_join_indexer_unique(readonly):
+def test_left_join_indexer_unique(writable):
     a = np.array([1, 2, 3, 4, 5], dtype=np.int64)
     b = np.array([2, 2, 3, 4, 4], dtype=np.int64)
-    if readonly:
-        # GH#37312, GH#37264
-        a.setflags(write=False)
-        b.setflags(write=False)
+    # GH#37312, GH#37264
+    a.setflags(write=writable)
+    b.setflags(write=writable)
 
     result = libjoin.left_join_indexer_unique(b, a)
     expected = np.array([1, 1, 2, 3, 3], dtype=np.intp)
diff --git a/pandas/tests/tools/test_to_datetime.py b/pandas/tests/tools/test_to_datetime.py
index a23d2d3dc22af..0ce1f7b0ff20e 100644
--- a/pandas/tests/tools/test_to_datetime.py
+++ b/pandas/tests/tools/test_to_datetime.py
@@ -71,12 +71,10 @@ def cache(request):
 
 
 class TestTimeConversionFormats:
-    @pytest.mark.parametrize("readonly", [True, False])
-    def test_to_datetime_readonly(self, readonly):
+    def test_to_datetime_readonly(self, writable):
         # GH#34857
         arr = np.array([], dtype=object)
-        if readonly:
-            arr.setflags(write=False)
+        arr.setflags(write=writable)
         result = to_datetime(arr)
         expected = to_datetime([])
         tm.assert_index_equal(result, expected)
diff --git a/pandas/tests/tools/test_to_timedelta.py b/pandas/tests/tools/test_to_timedelta.py
index b67694f1c58c7..036462674c270 100644
--- a/pandas/tests/tools/test_to_timedelta.py
+++ b/pandas/tests/tools/test_to_timedelta.py
@@ -32,12 +32,10 @@ def test_to_timedelta_dt64_raises(self):
         with pytest.raises(TypeError, match=msg):
             ser.to_frame().apply(to_timedelta)
 
-    @pytest.mark.parametrize("readonly", [True, False])
-    def test_to_timedelta_readonly(self, readonly):
+    def test_to_timedelta_readonly(self, writable):
         # GH#34857
         arr = np.array([], dtype=object)
-        if readonly:
-            arr.setflags(write=False)
+        arr.setflags(write=writable)
         result = to_timedelta(arr)
         expected = to_timedelta([])
         tm.assert_index_equal(result, expected)

From 39ab4b4951b85041812f1e9cc6c2b8b486c41903 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 12:05:17 -0800
Subject: [PATCH 09/26] Use top level other_closed

---
 pandas/tests/arrays/interval/test_interval.py | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/pandas/tests/arrays/interval/test_interval.py b/pandas/tests/arrays/interval/test_interval.py
index be4b2c3e7e74c..58ba340441d86 100644
--- a/pandas/tests/arrays/interval/test_interval.py
+++ b/pandas/tests/arrays/interval/test_interval.py
@@ -58,12 +58,11 @@ def test_is_empty(self, constructor, left, right, closed):
 
 
 class TestMethods:
-    @pytest.mark.parametrize("new_closed", ["left", "right", "both", "neither"])
-    def test_set_closed(self, closed, new_closed):
+    def test_set_closed(self, closed, other_closed):
         # GH 21670
         array = IntervalArray.from_breaks(range(10), closed=closed)
-        result = array.set_closed(new_closed)
-        expected = IntervalArray.from_breaks(range(10), closed=new_closed)
+        result = array.set_closed(other_closed)
+        expected = IntervalArray.from_breaks(range(10), closed=other_closed)
         tm.assert_extension_array_equal(result, expected)
 
     @pytest.mark.parametrize(

From 0c4829b8c22c251edb5699cf4697ec8ef0840913 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 12:10:12 -0800
Subject: [PATCH 10/26] Use top level join_type fixture

---
 pandas/tests/frame/methods/test_align.py          | 12 ++++++++++--
 pandas/tests/indexes/datetimes/test_date_range.py |  5 ++---
 pandas/tests/indexes/interval/test_indexing.py    |  1 -
 pandas/tests/indexes/interval/test_interval.py    |  7 +++----
 pandas/tests/reshape/merge/test_merge.py          | 15 ++++++++++-----
 pandas/tests/test_sorting.py                      |  9 ++++-----
 6 files changed, 29 insertions(+), 20 deletions(-)

diff --git a/pandas/tests/frame/methods/test_align.py b/pandas/tests/frame/methods/test_align.py
index 5a9c47866dae8..1f5d960de40c1 100644
--- a/pandas/tests/frame/methods/test_align.py
+++ b/pandas/tests/frame/methods/test_align.py
@@ -395,7 +395,6 @@ def test_missing_axis_specification_exception(self):
     @pytest.mark.parametrize("method", ["pad", "bfill"])
     @pytest.mark.parametrize("axis", [0, 1, None])
     @pytest.mark.parametrize("fill_axis", [0, 1])
-    @pytest.mark.parametrize("how", ["inner", "outer", "left", "right"])
     @pytest.mark.parametrize(
         "left_slice",
         [
@@ -412,8 +411,17 @@ def test_missing_axis_specification_exception(self):
     )
     @pytest.mark.parametrize("limit", [1, None])
     def test_align_fill_method(
-        self, how, method, axis, fill_axis, float_frame, left_slice, right_slice, limit
+        self,
+        join_type,
+        method,
+        axis,
+        fill_axis,
+        float_frame,
+        left_slice,
+        right_slice,
+        limit,
     ):
+        how = join_type
         frame = float_frame
         left = frame.iloc[left_slice[0], left_slice[1]]
         right = frame.iloc[right_slice[0], right_slice[1]]
diff --git a/pandas/tests/indexes/datetimes/test_date_range.py b/pandas/tests/indexes/datetimes/test_date_range.py
index 44dd64e162413..019d434680661 100644
--- a/pandas/tests/indexes/datetimes/test_date_range.py
+++ b/pandas/tests/indexes/datetimes/test_date_range.py
@@ -1093,12 +1093,11 @@ def test_daterange_bug_456(self):
         result = rng1.union(rng2)
         assert isinstance(result, DatetimeIndex)
 
-    @pytest.mark.parametrize("inclusive", ["left", "right", "neither", "both"])
-    def test_bdays_and_open_boundaries(self, inclusive):
+    def test_bdays_and_open_boundaries(self, inclusive_endpoints_fixture):
         # GH 6673
         start = "2018-07-21"  # Saturday
         end = "2018-07-29"  # Sunday
-        result = date_range(start, end, freq="B", inclusive=inclusive)
+        result = date_range(start, end, freq="B", inclusive=inclusive_endpoints_fixture)
 
         bday_start = "2018-07-23"  # Monday
         bday_end = "2018-07-27"  # Friday
diff --git a/pandas/tests/indexes/interval/test_indexing.py b/pandas/tests/indexes/interval/test_indexing.py
index fd03047b2c127..787461b944bd0 100644
--- a/pandas/tests/indexes/interval/test_indexing.py
+++ b/pandas/tests/indexes/interval/test_indexing.py
@@ -141,7 +141,6 @@ def test_get_loc_length_one_scalar(self, scalar, closed):
             with pytest.raises(KeyError, match=str(scalar)):
                 index.get_loc(scalar)
 
-    @pytest.mark.parametrize("other_closed", ["left", "right", "both", "neither"])
     @pytest.mark.parametrize("left, right", [(0, 5), (-1, 4), (-1, 6), (6, 7)])
     def test_get_loc_length_one_interval(self, left, right, closed, other_closed):
         # GH 20921
diff --git a/pandas/tests/indexes/interval/test_interval.py b/pandas/tests/indexes/interval/test_interval.py
index 63f9b2176dddd..89b991318be0d 100644
--- a/pandas/tests/indexes/interval/test_interval.py
+++ b/pandas/tests/indexes/interval/test_interval.py
@@ -865,12 +865,11 @@ def test_nbytes(self):
         expected = 64  # 4 * 8 * 2
         assert result == expected
 
-    @pytest.mark.parametrize("new_closed", ["left", "right", "both", "neither"])
-    def test_set_closed(self, name, closed, new_closed):
+    def test_set_closed(self, name, closed, other_closed):
         # GH 21670
         index = interval_range(0, 5, closed=closed, name=name)
-        result = index.set_closed(new_closed)
-        expected = interval_range(0, 5, closed=new_closed, name=name)
+        result = index.set_closed(other_closed)
+        expected = interval_range(0, 5, closed=other_closed, name=name)
         tm.assert_index_equal(result, expected)
 
     @pytest.mark.parametrize("bad_closed", ["foo", 10, "LEFT", True, False])
diff --git a/pandas/tests/reshape/merge/test_merge.py b/pandas/tests/reshape/merge/test_merge.py
index 3c0965308f8b7..d745367dac3a5 100644
--- a/pandas/tests/reshape/merge/test_merge.py
+++ b/pandas/tests/reshape/merge/test_merge.py
@@ -455,13 +455,12 @@ def test_left_merge_empty_dataframe(self):
         result = merge(right, left, on="key", how="right")
         tm.assert_frame_equal(result, left)
 
-    @pytest.mark.parametrize("how", ["inner", "left", "right", "outer"])
-    def test_merge_empty_dataframe(self, index, how):
+    def test_merge_empty_dataframe(self, index, join_type):
         # GH52777
         left = DataFrame([], index=index[:0])
         right = left.copy()
 
-        result = left.join(right, how=how)
+        result = left.join(right, how=join_type)
         tm.assert_frame_equal(result, left)
 
     @pytest.mark.parametrize(
@@ -2859,15 +2858,21 @@ def test_merge_multiindex_single_level():
     tm.assert_frame_equal(result, expected)
 
 
-@pytest.mark.parametrize("how", ["left", "right", "inner", "outer"])
 @pytest.mark.parametrize("on_index", [True, False])
 @pytest.mark.parametrize("left_unique", [True, False])
 @pytest.mark.parametrize("left_monotonic", [True, False])
 @pytest.mark.parametrize("right_unique", [True, False])
 @pytest.mark.parametrize("right_monotonic", [True, False])
 def test_merge_combinations(
-    how, sort, on_index, left_unique, left_monotonic, right_unique, right_monotonic
+    join_type,
+    sort,
+    on_index,
+    left_unique,
+    left_monotonic,
+    right_unique,
+    right_monotonic,
 ):
+    how = join_type
     # GH 54611
     left = [2, 3]
     if left_unique:
diff --git a/pandas/tests/test_sorting.py b/pandas/tests/test_sorting.py
index e692d8326c5ba..329fbac925539 100644
--- a/pandas/tests/test_sorting.py
+++ b/pandas/tests/test_sorting.py
@@ -218,14 +218,13 @@ def test_int64_overflow_check_sum_col(self, left_right):
         assert result.name is None
 
     @pytest.mark.slow
-    @pytest.mark.parametrize("how", ["left", "right", "outer", "inner"])
-    def test_int64_overflow_how_merge(self, left_right, how):
+    def test_int64_overflow_how_merge(self, left_right, join_type):
         left, right = left_right
 
         out = merge(left, right, how="outer")
         out.sort_values(out.columns.tolist(), inplace=True)
         out.index = np.arange(len(out))
-        tm.assert_frame_equal(out, merge(left, right, how=how, sort=True))
+        tm.assert_frame_equal(out, merge(left, right, how=join_type, sort=True))
 
     @pytest.mark.slow
     def test_int64_overflow_sort_false_order(self, left_right):
@@ -239,9 +238,9 @@ def test_int64_overflow_sort_false_order(self, left_right):
         tm.assert_frame_equal(right, out[right.columns.tolist()])
 
     @pytest.mark.slow
-    @pytest.mark.parametrize("how", ["left", "right", "outer", "inner"])
-    def test_int64_overflow_one_to_many_none_match(self, how, sort):
+    def test_int64_overflow_one_to_many_none_match(self, join_type, sort):
         # one-2-many/none match
+        how = join_type
         low, high, n = -1 << 10, 1 << 10, 1 << 11
         left = DataFrame(
             np.random.default_rng(2).integers(low, high, (n, 7)).astype("int64"),

From 45c02afaf8dafcaf04b62015e194c8ea3682fab9 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 12:11:17 -0800
Subject: [PATCH 11/26] use another join_type

---
 pandas/tests/reshape/merge/test_merge.py | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/pandas/tests/reshape/merge/test_merge.py b/pandas/tests/reshape/merge/test_merge.py
index d745367dac3a5..3382ed27a90a7 100644
--- a/pandas/tests/reshape/merge/test_merge.py
+++ b/pandas/tests/reshape/merge/test_merge.py
@@ -2818,9 +2818,8 @@ def test_merge_arrow_and_numpy_dtypes(dtype):
     tm.assert_frame_equal(result, expected)
 
 
-@pytest.mark.parametrize("how", ["inner", "left", "outer", "right"])
 @pytest.mark.parametrize("tz", [None, "America/Chicago"])
-def test_merge_datetime_different_resolution(tz, how):
+def test_merge_datetime_different_resolution(tz, join_type):
     # https://github.com/pandas-dev/pandas/issues/53200
     vals = [
         pd.Timestamp(2023, 5, 12, tz=tz),
@@ -2834,14 +2833,14 @@ def test_merge_datetime_different_resolution(tz, how):
 
     expected = DataFrame({"t": vals, "a": [1.0, 2.0, np.nan], "b": [np.nan, 1.0, 2.0]})
     expected["t"] = expected["t"].dt.as_unit("ns")
-    if how == "inner":
+    if join_type == "inner":
         expected = expected.iloc[[1]].reset_index(drop=True)
-    elif how == "left":
+    elif join_type == "left":
         expected = expected.iloc[[0, 1]]
-    elif how == "right":
+    elif join_type == "right":
         expected = expected.iloc[[1, 2]].reset_index(drop=True)
 
-    result = df1.merge(df2, on="t", how=how)
+    result = df1.merge(df2, on="t", how=join_type)
     tm.assert_frame_equal(result, expected)
 
 

From 4dd414b175f769e93a43288ac3da27624cc1bc19 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 12:15:33 -0800
Subject: [PATCH 12/26] Use another join_type

---
 pandas/tests/strings/test_cat.py | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/pandas/tests/strings/test_cat.py b/pandas/tests/strings/test_cat.py
index 284932491a65e..f54feabe49007 100644
--- a/pandas/tests/strings/test_cat.py
+++ b/pandas/tests/strings/test_cat.py
@@ -259,14 +259,13 @@ def test_str_cat_mixed_inputs(index_or_series):
         s.str.cat(iter([t.values, list(s)]))
 
 
-@pytest.mark.parametrize("join", ["left", "outer", "inner", "right"])
-def test_str_cat_align_indexed(index_or_series, join):
+def test_str_cat_align_indexed(index_or_series, join_type):
     # https://github.com/pandas-dev/pandas/issues/18657
     box = index_or_series
 
     s = Series(["a", "b", "c", "d"], index=["a", "b", "c", "d"])
     t = Series(["D", "A", "E", "B"], index=["d", "a", "e", "b"])
-    sa, ta = s.align(t, join=join)
+    sa, ta = s.align(t, join=join_type)
     # result after manual alignment of inputs
     expected = sa.str.cat(ta, na_rep="-")
 
@@ -275,25 +274,24 @@ def test_str_cat_align_indexed(index_or_series, join):
         sa = Index(sa)
         expected = Index(expected)
 
-    result = s.str.cat(t, join=join, na_rep="-")
+    result = s.str.cat(t, join=join_type, na_rep="-")
     tm.assert_equal(result, expected)
 
 
-@pytest.mark.parametrize("join", ["left", "outer", "inner", "right"])
-def test_str_cat_align_mixed_inputs(join):
+def test_str_cat_align_mixed_inputs(join_type):
     s = Series(["a", "b", "c", "d"])
     t = Series(["d", "a", "e", "b"], index=[3, 0, 4, 1])
     d = concat([t, t], axis=1)
 
     expected_outer = Series(["aaa", "bbb", "c--", "ddd", "-ee"])
-    expected = expected_outer.loc[s.index.join(t.index, how=join)]
+    expected = expected_outer.loc[s.index.join(t.index, how=join_type)]
 
     # list of Series
-    result = s.str.cat([t, t], join=join, na_rep="-")
+    result = s.str.cat([t, t], join=join_type, na_rep="-")
     tm.assert_series_equal(result, expected)
 
     # DataFrame
-    result = s.str.cat(d, join=join, na_rep="-")
+    result = s.str.cat(d, join=join_type, na_rep="-")
     tm.assert_series_equal(result, expected)
 
     # mixed list of indexed/unindexed
@@ -302,19 +300,19 @@ def test_str_cat_align_mixed_inputs(join):
     # joint index of rhs [t, u]; u will be forced have index of s
     rhs_idx = (
         t.index.intersection(s.index)
-        if join == "inner"
+        if join_type == "inner"
         else t.index.union(s.index)
-        if join == "outer"
+        if join_type == "outer"
         else t.index.append(s.index.difference(t.index))
     )
 
-    expected = expected_outer.loc[s.index.join(rhs_idx, how=join)]
-    result = s.str.cat([t, u], join=join, na_rep="-")
+    expected = expected_outer.loc[s.index.join(rhs_idx, how=join_type)]
+    result = s.str.cat([t, u], join=join_type, na_rep="-")
     tm.assert_series_equal(result, expected)
 
     with pytest.raises(TypeError, match="others must be Series,.*"):
         # nested lists are forbidden
-        s.str.cat([t, list(u)], join=join)
+        s.str.cat([t, list(u)], join=join_type)
 
     # errors for incorrect lengths
     rgx = r"If `others` contains arrays or lists \(or other list-likes.*"
@@ -322,11 +320,11 @@ def test_str_cat_align_mixed_inputs(join):
 
     # unindexed object of wrong length
     with pytest.raises(ValueError, match=rgx):
-        s.str.cat(z, join=join)
+        s.str.cat(z, join=join_type)
 
     # unindexed object of wrong length in list
     with pytest.raises(ValueError, match=rgx):
-        s.str.cat([t, z], join=join)
+        s.str.cat([t, z], join=join_type)
 
 
 def test_str_cat_all_na(index_or_series, index_or_series2):

From f37f7b236dbb357c6267cee8e0d7d50dc80d6f7f Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 12:17:50 -0800
Subject: [PATCH 13/26] use top level nselect_method

---
 pandas/tests/groupby/methods/test_nlargest_nsmallest.py | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/pandas/tests/groupby/methods/test_nlargest_nsmallest.py b/pandas/tests/groupby/methods/test_nlargest_nsmallest.py
index bf983f04a3f3f..1225c325c4c23 100644
--- a/pandas/tests/groupby/methods/test_nlargest_nsmallest.py
+++ b/pandas/tests/groupby/methods/test_nlargest_nsmallest.py
@@ -99,17 +99,16 @@ def test_nsmallest():
     [([0, 1, 2, 3], [0, 0, 1, 1]), ([0], [0])],
 )
 @pytest.mark.parametrize("dtype", [None, *tm.ALL_INT_NUMPY_DTYPES])
-@pytest.mark.parametrize("method", ["nlargest", "nsmallest"])
-def test_nlargest_and_smallest_noop(data, groups, dtype, method):
+def test_nlargest_and_smallest_noop(data, groups, dtype, nselect_method):
     # GH 15272, GH 16345, GH 29129
     # Test nlargest/smallest when it results in a noop,
     # i.e. input is sorted and group size <= n
     if dtype is not None:
         data = np.array(data, dtype=dtype)
-    if method == "nlargest":
+    if nselect_method == "nlargest":
         data = list(reversed(data))
     ser = Series(data, name="a")
-    result = getattr(ser.groupby(groups), method)(n=2)
+    result = getattr(ser.groupby(groups), nselect_method)(n=2)
     expidx = np.array(groups, dtype=int) if isinstance(groups, list) else groups
     expected = Series(data, index=MultiIndex.from_arrays([expidx, ser.index]), name="a")
     tm.assert_series_equal(result, expected)

From c78ede633937fdfdf420e1564289f6c62c9abdc9 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 13:11:00 -0800
Subject: [PATCH 14/26] Reuse all_boolean_reductions

---
 pandas/conftest.py                         |  4 --
 pandas/tests/dtypes/test_inference.py      |  4 +-
 pandas/tests/frame/test_reductions.py      | 47 +++++++++++-----------
 pandas/tests/groupby/test_reductions.py    | 40 +++++++++---------
 pandas/tests/indexes/test_base.py          |  9 ++---
 pandas/tests/reductions/test_reductions.py | 19 ++++-----
 pandas/tests/strings/test_cat.py           |  5 +++
 7 files changed, 60 insertions(+), 68 deletions(-)

diff --git a/pandas/conftest.py b/pandas/conftest.py
index 51bf494361862..85443843b041e 100644
--- a/pandas/conftest.py
+++ b/pandas/conftest.py
@@ -483,10 +483,6 @@ def index_or_series(request):
     return request.param
 
 
-# Generate cartesian product of index_or_series fixture:
-index_or_series2 = index_or_series
-
-
 @pytest.fixture(params=[Index, Series, pd.array], ids=["index", "series", "array"])
 def index_or_series_or_array(request):
     """
diff --git a/pandas/tests/dtypes/test_inference.py b/pandas/tests/dtypes/test_inference.py
index 82db41de27117..8c3407deb9292 100644
--- a/pandas/tests/dtypes/test_inference.py
+++ b/pandas/tests/dtypes/test_inference.py
@@ -1339,8 +1339,8 @@ def test_infer_dtype_period(self):
         arr = np.array([Period("2011-01", freq="D"), Period("2011-02", freq="M")])
         assert lib.infer_dtype(arr, skipna=True) == "mixed"
 
-    @pytest.mark.parametrize("klass", [pd.array, Series, Index])
-    def test_infer_dtype_period_array(self, klass, skipna):
+    def test_infer_dtype_period_array(self, index_or_series_or_array, skipna):
+        klass = index_or_series_or_array
         # https://github.com/pandas-dev/pandas/issues/23553
         values = klass(
             [
diff --git a/pandas/tests/frame/test_reductions.py b/pandas/tests/frame/test_reductions.py
index 1ef863c02c35e..04ba3bc70daa5 100644
--- a/pandas/tests/frame/test_reductions.py
+++ b/pandas/tests/frame/test_reductions.py
@@ -1264,29 +1264,30 @@ def test_idxmax_dt64_multicolumn_axis1(self):
     # ----------------------------------------------------------------------
     # Logical reductions
 
-    @pytest.mark.parametrize("opname", ["any", "all"])
     @pytest.mark.parametrize("axis", [0, 1])
     @pytest.mark.parametrize("bool_only", [False, True])
-    def test_any_all_mixed_float(self, opname, axis, bool_only, float_string_frame):
+    def test_any_all_mixed_float(
+        self, all_boolean_reductions, axis, bool_only, float_string_frame
+    ):
         # make sure op works on mixed-type frame
         mixed = float_string_frame
         mixed["_bool_"] = np.random.default_rng(2).standard_normal(len(mixed)) > 0.5
 
-        getattr(mixed, opname)(axis=axis, bool_only=bool_only)
+        getattr(mixed, all_boolean_reductions)(axis=axis, bool_only=bool_only)
 
-    @pytest.mark.parametrize("opname", ["any", "all"])
     @pytest.mark.parametrize("axis", [0, 1])
-    def test_any_all_bool_with_na(self, opname, axis, bool_frame_with_na):
-        getattr(bool_frame_with_na, opname)(axis=axis, bool_only=False)
+    def test_any_all_bool_with_na(
+        self, all_boolean_reductions, axis, bool_frame_with_na
+    ):
+        getattr(bool_frame_with_na, all_boolean_reductions)(axis=axis, bool_only=False)
 
     @pytest.mark.filterwarnings("ignore:Downcasting object dtype arrays:FutureWarning")
-    @pytest.mark.parametrize("opname", ["any", "all"])
-    def test_any_all_bool_frame(self, opname, bool_frame_with_na):
+    def test_any_all_bool_frame(self, all_boolean_reductions, bool_frame_with_na):
         # GH#12863: numpy gives back non-boolean data for object type
         # so fill NaNs to compare with pandas behavior
         frame = bool_frame_with_na.fillna(True)
-        alternative = getattr(np, opname)
-        f = getattr(frame, opname)
+        alternative = getattr(np, all_boolean_reductions)
+        f = getattr(frame, all_boolean_reductions)
 
         def skipna_wrapper(x):
             nona = x.dropna().values
@@ -1315,9 +1316,9 @@ def wrapper(x):
 
         # all NA case
         all_na = frame * np.nan
-        r0 = getattr(all_na, opname)(axis=0)
-        r1 = getattr(all_na, opname)(axis=1)
-        if opname == "any":
+        r0 = getattr(all_na, all_boolean_reductions)(axis=0)
+        r1 = getattr(all_na, all_boolean_reductions)(axis=1)
+        if all_boolean_reductions == "any":
             assert not r0.any()
             assert not r1.any()
         else:
@@ -1358,9 +1359,8 @@ def test_any_all_extra(self):
         assert result is True
 
     @pytest.mark.parametrize("axis", [0, 1])
-    @pytest.mark.parametrize("bool_agg_func", ["any", "all"])
     def test_any_all_object_dtype(
-        self, axis, bool_agg_func, skipna, using_infer_string
+        self, axis, all_boolean_reductions, skipna, using_infer_string
     ):
         # GH#35450
         df = DataFrame(
@@ -1373,10 +1373,10 @@ def test_any_all_object_dtype(
         )
         if using_infer_string:
             # na in object is True while in string pyarrow numpy it's false
-            val = not axis == 0 and not skipna and bool_agg_func == "all"
+            val = not axis == 0 and not skipna and all_boolean_reductions == "all"
         else:
             val = True
-        result = getattr(df, bool_agg_func)(axis=axis, skipna=skipna)
+        result = getattr(df, all_boolean_reductions)(axis=axis, skipna=skipna)
         expected = Series([True, True, val, True])
         tm.assert_series_equal(result, expected)
 
@@ -1745,27 +1745,26 @@ def test_reduction_timedelta_smallest_unit(self):
 
 
 class TestNuisanceColumns:
-    @pytest.mark.parametrize("method", ["any", "all"])
-    def test_any_all_categorical_dtype_nuisance_column(self, method):
+    def test_any_all_categorical_dtype_nuisance_column(self, all_boolean_reductions):
         # GH#36076 DataFrame should match Series behavior
         ser = Series([0, 1], dtype="category", name="A")
         df = ser.to_frame()
 
         # Double-check the Series behavior is to raise
         with pytest.raises(TypeError, match="does not support reduction"):
-            getattr(ser, method)()
+            getattr(ser, all_boolean_reductions)()
 
         with pytest.raises(TypeError, match="does not support reduction"):
-            getattr(np, method)(ser)
+            getattr(np, all_boolean_reductions)(ser)
 
         with pytest.raises(TypeError, match="does not support reduction"):
-            getattr(df, method)(bool_only=False)
+            getattr(df, all_boolean_reductions)(bool_only=False)
 
         with pytest.raises(TypeError, match="does not support reduction"):
-            getattr(df, method)(bool_only=None)
+            getattr(df, all_boolean_reductions)(bool_only=None)
 
         with pytest.raises(TypeError, match="does not support reduction"):
-            getattr(np, method)(df, axis=0)
+            getattr(np, all_boolean_reductions)(df, axis=0)
 
     def test_median_categorical_dtype_nuisance_column(self):
         # GH#21020 DataFrame.median should match Series.median
diff --git a/pandas/tests/groupby/test_reductions.py b/pandas/tests/groupby/test_reductions.py
index c8678156d0c75..ba73bf3b9908a 100644
--- a/pandas/tests/groupby/test_reductions.py
+++ b/pandas/tests/groupby/test_reductions.py
@@ -20,7 +20,6 @@
 from pandas.util import _test_decorators as td
 
 
-@pytest.mark.parametrize("agg_func", ["any", "all"])
 @pytest.mark.parametrize(
     "vals",
     [
@@ -39,20 +38,20 @@
         [np.nan, np.nan, np.nan],
     ],
 )
-def test_groupby_bool_aggs(skipna, agg_func, vals):
+def test_groupby_bool_aggs(skipna, all_boolean_reductions, vals):
     df = DataFrame({"key": ["a"] * 3 + ["b"] * 3, "val": vals * 2})
 
     # Figure out expectation using Python builtin
-    exp = getattr(builtins, agg_func)(vals)
+    exp = getattr(builtins, all_boolean_reductions)(vals)
 
     # edge case for missing data with skipna and 'any'
-    if skipna and all(isna(vals)) and agg_func == "any":
+    if skipna and all(isna(vals)) and all_boolean_reductions == "any":
         exp = False
 
     expected = DataFrame(
         [exp] * 2, columns=["val"], index=pd.Index(["a", "b"], name="key")
     )
-    result = getattr(df.groupby("key"), agg_func)(skipna=skipna)
+    result = getattr(df.groupby("key"), all_boolean_reductions)(skipna=skipna)
     tm.assert_frame_equal(result, expected)
 
 
@@ -69,18 +68,16 @@ def test_any():
     tm.assert_frame_equal(result, expected)
 
 
-@pytest.mark.parametrize("bool_agg_func", ["any", "all"])
-def test_bool_aggs_dup_column_labels(bool_agg_func):
+def test_bool_aggs_dup_column_labels(all_boolean_reductions):
     # GH#21668
     df = DataFrame([[True, True]], columns=["a", "a"])
     grp_by = df.groupby([0])
-    result = getattr(grp_by, bool_agg_func)()
+    result = getattr(grp_by, all_boolean_reductions)()
 
     expected = df.set_axis(np.array([0]))
     tm.assert_frame_equal(result, expected)
 
 
-@pytest.mark.parametrize("bool_agg_func", ["any", "all"])
 @pytest.mark.parametrize(
     "data",
     [
@@ -92,16 +89,16 @@ def test_bool_aggs_dup_column_labels(bool_agg_func):
         [True, pd.NA, False],
     ],
 )
-def test_masked_kleene_logic(bool_agg_func, skipna, data):
+def test_masked_kleene_logic(all_boolean_reductions, skipna, data):
     # GH#37506
     ser = Series(data, dtype="boolean")
 
     # The result should match aggregating on the whole series. Correctness
     # there is verified in test_reductions.py::test_any_all_boolean_kleene_logic
-    expected_data = getattr(ser, bool_agg_func)(skipna=skipna)
+    expected_data = getattr(ser, all_boolean_reductions)(skipna=skipna)
     expected = Series(expected_data, index=np.array([0]), dtype="boolean")
 
-    result = ser.groupby([0, 0, 0]).agg(bool_agg_func, skipna=skipna)
+    result = ser.groupby([0, 0, 0]).agg(all_boolean_reductions, skipna=skipna)
     tm.assert_series_equal(result, expected)
 
 
@@ -146,17 +143,18 @@ def test_masked_mixed_types(dtype1, dtype2, exp_col1, exp_col2):
     tm.assert_frame_equal(result, expected)
 
 
-@pytest.mark.parametrize("bool_agg_func", ["any", "all"])
 @pytest.mark.parametrize("dtype", ["Int64", "Float64", "boolean"])
-def test_masked_bool_aggs_skipna(bool_agg_func, dtype, skipna, frame_or_series):
+def test_masked_bool_aggs_skipna(
+    all_boolean_reductions, dtype, skipna, frame_or_series
+):
     # GH#40585
     obj = frame_or_series([pd.NA, 1], dtype=dtype)
     expected_res = True
-    if not skipna and bool_agg_func == "all":
+    if not skipna and all_boolean_reductions == "all":
         expected_res = pd.NA
     expected = frame_or_series([expected_res], index=np.array([1]), dtype="boolean")
 
-    result = obj.groupby([1, 1]).agg(bool_agg_func, skipna=skipna)
+    result = obj.groupby([1, 1]).agg(all_boolean_reductions, skipna=skipna)
     tm.assert_equal(result, expected)
 
 
@@ -177,20 +175,18 @@ def test_object_type_missing_vals(bool_agg_func, data, expected_res, frame_or_se
     tm.assert_equal(result, expected)
 
 
-@pytest.mark.parametrize("bool_agg_func", ["any", "all"])
-def test_object_NA_raises_with_skipna_false(bool_agg_func):
+def test_object_NA_raises_with_skipna_false(all_boolean_reductions):
     # GH#37501
     ser = Series([pd.NA], dtype=object)
     with pytest.raises(TypeError, match="boolean value of NA is ambiguous"):
-        ser.groupby([1]).agg(bool_agg_func, skipna=False)
+        ser.groupby([1]).agg(all_boolean_reductions, skipna=False)
 
 
-@pytest.mark.parametrize("bool_agg_func", ["any", "all"])
-def test_empty(frame_or_series, bool_agg_func):
+def test_empty(frame_or_series, all_boolean_reductions):
     # GH 45231
     kwargs = {"columns": ["a"]} if frame_or_series is DataFrame else {"name": "a"}
     obj = frame_or_series(**kwargs, dtype=object)
-    result = getattr(obj.groupby(obj.index), bool_agg_func)()
+    result = getattr(obj.groupby(obj.index), all_boolean_reductions)()
     expected = frame_or_series(**kwargs, dtype=bool)
     tm.assert_equal(result, expected)
 
diff --git a/pandas/tests/indexes/test_base.py b/pandas/tests/indexes/test_base.py
index 185e34efdc177..8cafb089ae69c 100644
--- a/pandas/tests/indexes/test_base.py
+++ b/pandas/tests/indexes/test_base.py
@@ -720,12 +720,11 @@ def test_format_missing(self, vals, nulls_fixture):
         assert formatted == expected
         assert index[3] is nulls_fixture
 
-    @pytest.mark.parametrize("op", ["any", "all"])
-    def test_logical_compat(self, op, simple_index):
+    def test_logical_compat(self, all_boolean_reductions, simple_index):
         index = simple_index
-        left = getattr(index, op)()
-        assert left == getattr(index.values, op)()
-        right = getattr(index.to_series(), op)()
+        left = getattr(index, all_boolean_reductions)()
+        assert left == getattr(index.values, all_boolean_reductions)()
+        right = getattr(index.to_series(), all_boolean_reductions)()
         # left might not match right exactly in e.g. string cases where the
         # because we use np.any/all instead of .any/all
         assert bool(left) == bool(right)
diff --git a/pandas/tests/reductions/test_reductions.py b/pandas/tests/reductions/test_reductions.py
index 27a802d14c23e..fcb5b65e59402 100644
--- a/pandas/tests/reductions/test_reductions.py
+++ b/pandas/tests/reductions/test_reductions.py
@@ -985,30 +985,27 @@ def test_all_any_bool_only(self):
         assert s.any(bool_only=True)
         assert not s.all(bool_only=True)
 
-    @pytest.mark.parametrize("bool_agg_func", ["any", "all"])
-    def test_any_all_object_dtype(self, bool_agg_func, skipna):
+    def test_any_all_object_dtype(self, all_boolean_reductions, skipna):
         # GH#12863
         ser = Series(["a", "b", "c", "d", "e"], dtype=object)
-        result = getattr(ser, bool_agg_func)(skipna=skipna)
+        result = getattr(ser, all_boolean_reductions)(skipna=skipna)
         expected = True
 
         assert result == expected
 
-    @pytest.mark.parametrize("bool_agg_func", ["any", "all"])
     @pytest.mark.parametrize(
         "data", [[False, None], [None, False], [False, np.nan], [np.nan, False]]
     )
-    def test_any_all_object_dtype_missing(self, data, bool_agg_func):
+    def test_any_all_object_dtype_missing(self, data, all_boolean_reductions):
         # GH#27709
         ser = Series(data)
-        result = getattr(ser, bool_agg_func)(skipna=False)
+        result = getattr(ser, all_boolean_reductions)(skipna=False)
 
         # None is treated is False, but np.nan is treated as True
-        expected = bool_agg_func == "any" and None not in data
+        expected = all_boolean_reductions == "any" and None not in data
         assert result == expected
 
     @pytest.mark.parametrize("dtype", ["boolean", "Int64", "UInt64", "Float64"])
-    @pytest.mark.parametrize("bool_agg_func", ["any", "all"])
     @pytest.mark.parametrize(
         # expected_data indexed as [[skipna=False/any, skipna=False/all],
         #                           [skipna=True/any, skipna=True/all]]
@@ -1023,13 +1020,13 @@ def test_any_all_object_dtype_missing(self, data, bool_agg_func):
         ],
     )
     def test_any_all_nullable_kleene_logic(
-        self, bool_agg_func, skipna, data, dtype, expected_data
+        self, all_boolean_reductions, skipna, data, dtype, expected_data
     ):
         # GH-37506, GH-41967
         ser = Series(data, dtype=dtype)
-        expected = expected_data[skipna][bool_agg_func == "all"]
+        expected = expected_data[skipna][all_boolean_reductions == "all"]
 
-        result = getattr(ser, bool_agg_func)(skipna=skipna)
+        result = getattr(ser, all_boolean_reductions)(skipna=skipna)
         assert (result is pd.NA and expected is pd.NA) or result == expected
 
     def test_any_axis1_bool_only(self):
diff --git a/pandas/tests/strings/test_cat.py b/pandas/tests/strings/test_cat.py
index f54feabe49007..26da2d2718f20 100644
--- a/pandas/tests/strings/test_cat.py
+++ b/pandas/tests/strings/test_cat.py
@@ -16,6 +16,11 @@
 )
 
 
+@pytest.fixture
+def index_or_series2(index_or_series):
+    return index_or_series
+
+
 @pytest.mark.parametrize("other", [None, Series, Index])
 def test_str_cat_name(index_or_series, other):
     # GH 21053

From 33a2697685d079eb34c0b05e19d3b8769f882a80 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 13:15:57 -0800
Subject: [PATCH 15/26] reuse all_numeric_accumulations

---
 pandas/tests/frame/test_cumulative.py            | 16 +++++++++-------
 pandas/tests/groupby/transform/test_transform.py |  5 ++---
 2 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/pandas/tests/frame/test_cumulative.py b/pandas/tests/frame/test_cumulative.py
index 5bd9c42612315..d7aad680d389e 100644
--- a/pandas/tests/frame/test_cumulative.py
+++ b/pandas/tests/frame/test_cumulative.py
@@ -7,7 +7,6 @@
 """
 
 import numpy as np
-import pytest
 
 from pandas import (
     DataFrame,
@@ -46,20 +45,23 @@ def test_cumprod_smoke(self, datetime_frame):
         df.cumprod(0)
         df.cumprod(1)
 
-    @pytest.mark.parametrize("method", ["cumsum", "cumprod", "cummin", "cummax"])
-    def test_cumulative_ops_match_series_apply(self, datetime_frame, method):
+    def test_cumulative_ops_match_series_apply(
+        self, datetime_frame, all_numeric_accumulations
+    ):
         datetime_frame.iloc[5:10, 0] = np.nan
         datetime_frame.iloc[10:15, 1] = np.nan
         datetime_frame.iloc[15:, 2] = np.nan
 
         # axis = 0
-        result = getattr(datetime_frame, method)()
-        expected = datetime_frame.apply(getattr(Series, method))
+        result = getattr(datetime_frame, all_numeric_accumulations)()
+        expected = datetime_frame.apply(getattr(Series, all_numeric_accumulations))
         tm.assert_frame_equal(result, expected)
 
         # axis = 1
-        result = getattr(datetime_frame, method)(axis=1)
-        expected = datetime_frame.apply(getattr(Series, method), axis=1)
+        result = getattr(datetime_frame, all_numeric_accumulations)(axis=1)
+        expected = datetime_frame.apply(
+            getattr(Series, all_numeric_accumulations), axis=1
+        )
         tm.assert_frame_equal(result, expected)
 
         # fix issue TODO: GH ref?
diff --git a/pandas/tests/groupby/transform/test_transform.py b/pandas/tests/groupby/transform/test_transform.py
index a2ecd6c65db60..f7a4233b3ddc9 100644
--- a/pandas/tests/groupby/transform/test_transform.py
+++ b/pandas/tests/groupby/transform/test_transform.py
@@ -1239,15 +1239,14 @@ def test_groupby_transform_dtype():
     tm.assert_series_equal(result, expected1)
 
 
-@pytest.mark.parametrize("func", ["cumsum", "cumprod", "cummin", "cummax"])
-def test_transform_absent_categories(func):
+def test_transform_absent_categories(all_numeric_accumulations):
     # GH 16771
     # cython transforms with more groups than rows
     x_vals = [1]
     x_cats = range(2)
     y = [1]
     df = DataFrame({"x": Categorical(x_vals, x_cats), "y": y})
-    result = getattr(df.y.groupby(df.x, observed=False), func)()
+    result = getattr(df.y.groupby(df.x, observed=False), all_numeric_accumulations)()
     expected = df.y
     tm.assert_series_equal(result, expected)
 

From 1dd3383de9431d0c25f2b6ba06a2db6250a9db67 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 13:24:03 -0800
Subject: [PATCH 16/26] Use shared na_action fixture

---
 pandas/conftest.py                          | 8 ++++++++
 pandas/tests/arrays/categorical/test_map.py | 5 -----
 pandas/tests/extension/base/methods.py      | 1 -
 pandas/tests/extension/test_arrow.py        | 1 -
 pandas/tests/extension/test_categorical.py  | 1 -
 pandas/tests/extension/test_datetime.py     | 1 -
 pandas/tests/extension/test_masked.py       | 1 -
 pandas/tests/extension/test_period.py       | 1 -
 pandas/tests/extension/test_sparse.py       | 1 -
 pandas/tests/frame/methods/test_map.py      | 1 -
 pandas/tests/series/methods/test_map.py     | 4 ----
 11 files changed, 8 insertions(+), 17 deletions(-)

diff --git a/pandas/conftest.py b/pandas/conftest.py
index 85443843b041e..b19c3b9ded82f 100644
--- a/pandas/conftest.py
+++ b/pandas/conftest.py
@@ -419,6 +419,14 @@ def nselect_method(request):
     return request.param
 
 
+@pytest.fixture(params=[None, "ignore"])
+def na_action(request):
+    """
+    Fixture for 'na_action' argument in map.
+    """
+    return request.param
+
+
 # ----------------------------------------------------------------
 # Missing values & co.
 # ----------------------------------------------------------------
diff --git a/pandas/tests/arrays/categorical/test_map.py b/pandas/tests/arrays/categorical/test_map.py
index 3d41b7cc7094d..763ca9180e53a 100644
--- a/pandas/tests/arrays/categorical/test_map.py
+++ b/pandas/tests/arrays/categorical/test_map.py
@@ -10,11 +10,6 @@
 import pandas._testing as tm
 
 
-@pytest.fixture(params=[None, "ignore"])
-def na_action(request):
-    return request.param
-
-
 @pytest.mark.parametrize(
     "data, categories",
     [
diff --git a/pandas/tests/extension/base/methods.py b/pandas/tests/extension/base/methods.py
index 88ef67605de98..a37493d44ff87 100644
--- a/pandas/tests/extension/base/methods.py
+++ b/pandas/tests/extension/base/methods.py
@@ -97,7 +97,6 @@ def test_apply_simple_series(self, data):
         result = pd.Series(data).apply(id)
         assert isinstance(result, pd.Series)
 
-    @pytest.mark.parametrize("na_action", [None, "ignore"])
     def test_map(self, data_missing, na_action):
         result = data_missing.map(lambda x: x, na_action=na_action)
         expected = data_missing.to_numpy()
diff --git a/pandas/tests/extension/test_arrow.py b/pandas/tests/extension/test_arrow.py
index d4a4bc8bb8bd3..2634d40639661 100644
--- a/pandas/tests/extension/test_arrow.py
+++ b/pandas/tests/extension/test_arrow.py
@@ -271,7 +271,6 @@ def test_compare_scalar(self, data, comparison_op):
         ser = pd.Series(data)
         self._compare_other(ser, data, comparison_op, data[0])
 
-    @pytest.mark.parametrize("na_action", [None, "ignore"])
     def test_map(self, data_missing, na_action):
         if data_missing.dtype.kind in "mM":
             result = data_missing.map(lambda x: x, na_action=na_action)
diff --git a/pandas/tests/extension/test_categorical.py b/pandas/tests/extension/test_categorical.py
index 6f33b18b19c51..74a5110de2c8e 100644
--- a/pandas/tests/extension/test_categorical.py
+++ b/pandas/tests/extension/test_categorical.py
@@ -143,7 +143,6 @@ def test_combine_add(self, data_repeated):
         expected = pd.Series([a + val for a in list(orig_data1)])
         tm.assert_series_equal(result, expected)
 
-    @pytest.mark.parametrize("na_action", [None, "ignore"])
     def test_map(self, data, na_action):
         result = data.map(lambda x: x, na_action=na_action)
         tm.assert_extension_array_equal(result, data)
diff --git a/pandas/tests/extension/test_datetime.py b/pandas/tests/extension/test_datetime.py
index a60ece09dc73e..15373527c871e 100644
--- a/pandas/tests/extension/test_datetime.py
+++ b/pandas/tests/extension/test_datetime.py
@@ -107,7 +107,6 @@ def test_series_constructor(self, data):
         data = data._with_freq(None)
         super().test_series_constructor(data)
 
-    @pytest.mark.parametrize("na_action", [None, "ignore"])
     def test_map(self, data, na_action):
         result = data.map(lambda x: x, na_action=na_action)
         tm.assert_extension_array_equal(result, data)
diff --git a/pandas/tests/extension/test_masked.py b/pandas/tests/extension/test_masked.py
index 3efc561d6a125..0e19c4078b471 100644
--- a/pandas/tests/extension/test_masked.py
+++ b/pandas/tests/extension/test_masked.py
@@ -169,7 +169,6 @@ def data_for_grouping(dtype):
 
 
 class TestMaskedArrays(base.ExtensionTests):
-    @pytest.mark.parametrize("na_action", [None, "ignore"])
     def test_map(self, data_missing, na_action):
         result = data_missing.map(lambda x: x, na_action=na_action)
         if data_missing.dtype == Float32Dtype():
diff --git a/pandas/tests/extension/test_period.py b/pandas/tests/extension/test_period.py
index 2d1d213322bac..4fe9c160d66af 100644
--- a/pandas/tests/extension/test_period.py
+++ b/pandas/tests/extension/test_period.py
@@ -109,7 +109,6 @@ def test_diff(self, data, periods):
         else:
             super().test_diff(data, periods)
 
-    @pytest.mark.parametrize("na_action", [None, "ignore"])
     def test_map(self, data, na_action):
         result = data.map(lambda x: x, na_action=na_action)
         tm.assert_extension_array_equal(result, data)
diff --git a/pandas/tests/extension/test_sparse.py b/pandas/tests/extension/test_sparse.py
index 4c6550ff191a5..d0f55dde998b1 100644
--- a/pandas/tests/extension/test_sparse.py
+++ b/pandas/tests/extension/test_sparse.py
@@ -366,7 +366,6 @@ def test_map(self, func, na_action, expected):
         result = data.map(func, na_action=na_action)
         tm.assert_extension_array_equal(result, expected)
 
-    @pytest.mark.parametrize("na_action", [None, "ignore"])
     def test_map_raises(self, data, na_action):
         # GH52096
         msg = "fill value in the sparse values not supported"
diff --git a/pandas/tests/frame/methods/test_map.py b/pandas/tests/frame/methods/test_map.py
index 03681c3df844e..a60dcf9a02938 100644
--- a/pandas/tests/frame/methods/test_map.py
+++ b/pandas/tests/frame/methods/test_map.py
@@ -33,7 +33,6 @@ def test_map_float_object_conversion(val):
     assert result == object
 
 
-@pytest.mark.parametrize("na_action", [None, "ignore"])
 def test_map_keeps_dtype(na_action):
     # GH52219
     arr = Series(["a", np.nan, "b"])
diff --git a/pandas/tests/series/methods/test_map.py b/pandas/tests/series/methods/test_map.py
index 251d4063008b9..f4f72854e50d3 100644
--- a/pandas/tests/series/methods/test_map.py
+++ b/pandas/tests/series/methods/test_map.py
@@ -326,7 +326,6 @@ def test_map_dict_na_key():
     tm.assert_series_equal(result, expected)
 
 
-@pytest.mark.parametrize("na_action", [None, "ignore"])
 def test_map_defaultdict_na_key(na_action):
     # GH 48813
     s = Series([1, 2, np.nan])
@@ -336,7 +335,6 @@ def test_map_defaultdict_na_key(na_action):
     tm.assert_series_equal(result, expected)
 
 
-@pytest.mark.parametrize("na_action", [None, "ignore"])
 def test_map_defaultdict_missing_key(na_action):
     # GH 48813
     s = Series([1, 2, np.nan])
@@ -346,7 +344,6 @@ def test_map_defaultdict_missing_key(na_action):
     tm.assert_series_equal(result, expected)
 
 
-@pytest.mark.parametrize("na_action", [None, "ignore"])
 def test_map_defaultdict_unmutated(na_action):
     # GH 48813
     s = Series([1, 2, np.nan])
@@ -483,7 +480,6 @@ def test_map_box_period():
     tm.assert_series_equal(res, exp)
 
 
-@pytest.mark.parametrize("na_action", [None, "ignore"])
 def test_map_categorical(na_action, using_infer_string):
     values = pd.Categorical(list("ABBABCD"), categories=list("DCBA"), ordered=True)
     s = Series(values, name="XX", index=list("abcdefg"))

From 6c92811d12fc654c37628236f0ef518663db128c Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 14:17:16 -0800
Subject: [PATCH 17/26] Use top level ascending fixture

---
 pandas/conftest.py                                |  8 ++++++++
 pandas/tests/arrays/datetimes/test_reductions.py  |  4 ----
 pandas/tests/arrays/test_datetimes.py             |  5 -----
 pandas/tests/extension/base/methods.py            |  3 ---
 pandas/tests/extension/json/test_json.py          | 12 ------------
 pandas/tests/extension/test_datetime.py           |  6 +++---
 pandas/tests/frame/methods/test_asfreq.py         |  4 ----
 pandas/tests/frame/methods/test_sort_index.py     |  1 -
 pandas/tests/frame/methods/test_sort_values.py    |  6 ------
 pandas/tests/groupby/methods/test_rank.py         |  2 --
 pandas/tests/groupby/methods/test_value_counts.py |  1 -
 pandas/tests/indexes/datetimes/test_formats.py    |  5 -----
 pandas/tests/resample/test_datetime_index.py      |  5 -----
 pandas/tests/reshape/merge/test_merge_asof.py     |  8 --------
 pandas/tests/series/methods/test_rank.py          |  1 -
 pandas/tests/series/methods/test_sort_values.py   |  1 -
 pandas/tests/test_nanops.py                       |  4 ----
 pandas/tests/window/test_expanding.py             |  1 -
 pandas/tests/window/test_rolling.py               |  1 -
 19 files changed, 11 insertions(+), 67 deletions(-)

diff --git a/pandas/conftest.py b/pandas/conftest.py
index b19c3b9ded82f..a32476f161863 100644
--- a/pandas/conftest.py
+++ b/pandas/conftest.py
@@ -427,6 +427,14 @@ def na_action(request):
     return request.param
 
 
+@pytest.fixture(params=[True, False])
+def ascending(request):
+    """
+    Fixture for 'na_action' argument in sort_values/sort_index/rank.
+    """
+    return request.param
+
+
 # ----------------------------------------------------------------
 # Missing values & co.
 # ----------------------------------------------------------------
diff --git a/pandas/tests/arrays/datetimes/test_reductions.py b/pandas/tests/arrays/datetimes/test_reductions.py
index 7d83fe6ffac7d..a58b0f57bf0da 100644
--- a/pandas/tests/arrays/datetimes/test_reductions.py
+++ b/pandas/tests/arrays/datetimes/test_reductions.py
@@ -10,10 +10,6 @@
 
 
 class TestReductions:
-    @pytest.fixture(params=["s", "ms", "us", "ns"])
-    def unit(self, request):
-        return request.param
-
     @pytest.fixture
     def arr1d(self, tz_naive_fixture):
         """Fixture returning DatetimeArray with parametrized timezones"""
diff --git a/pandas/tests/arrays/test_datetimes.py b/pandas/tests/arrays/test_datetimes.py
index db86f62a10484..675d500ca4401 100644
--- a/pandas/tests/arrays/test_datetimes.py
+++ b/pandas/tests/arrays/test_datetimes.py
@@ -28,11 +28,6 @@
 
 
 class TestNonNano:
-    @pytest.fixture(params=["s", "ms", "us"])
-    def unit(self, request):
-        """Fixture returning parametrized time units"""
-        return request.param
-
     @pytest.fixture
     def dtype(self, unit, tz_naive_fixture):
         tz = tz_naive_fixture
diff --git a/pandas/tests/extension/base/methods.py b/pandas/tests/extension/base/methods.py
index a37493d44ff87..6de5c97cbfb5e 100644
--- a/pandas/tests/extension/base/methods.py
+++ b/pandas/tests/extension/base/methods.py
@@ -212,7 +212,6 @@ def test_nargsort(self, data_missing_for_sorting, na_position, expected):
         result = nargsort(data_missing_for_sorting, na_position=na_position)
         tm.assert_numpy_array_equal(result, expected)
 
-    @pytest.mark.parametrize("ascending", [True, False])
     def test_sort_values(self, data_for_sorting, ascending, sort_by_key):
         ser = pd.Series(data_for_sorting)
         result = ser.sort_values(ascending=ascending, key=sort_by_key)
@@ -226,7 +225,6 @@ def test_sort_values(self, data_for_sorting, ascending, sort_by_key):
 
         tm.assert_series_equal(result, expected)
 
-    @pytest.mark.parametrize("ascending", [True, False])
     def test_sort_values_missing(
         self, data_missing_for_sorting, ascending, sort_by_key
     ):
@@ -238,7 +236,6 @@ def test_sort_values_missing(
             expected = ser.iloc[[0, 2, 1]]
         tm.assert_series_equal(result, expected)
 
-    @pytest.mark.parametrize("ascending", [True, False])
     def test_sort_values_frame(self, data_for_sorting, ascending):
         df = pd.DataFrame({"A": [1, 2, 1], "B": data_for_sorting})
         result = df.sort_values(["A", "B"])
diff --git a/pandas/tests/extension/json/test_json.py b/pandas/tests/extension/json/test_json.py
index 7686bc5abb44c..5319291f2ea01 100644
--- a/pandas/tests/extension/json/test_json.py
+++ b/pandas/tests/extension/json/test_json.py
@@ -162,18 +162,6 @@ def test_sort_values_frame(self):
         # TODO (EA.factorize): see if _values_for_factorize allows this.
         super().test_sort_values_frame()
 
-    @pytest.mark.parametrize("ascending", [True, False])
-    def test_sort_values(self, data_for_sorting, ascending, sort_by_key):
-        super().test_sort_values(data_for_sorting, ascending, sort_by_key)
-
-    @pytest.mark.parametrize("ascending", [True, False])
-    def test_sort_values_missing(
-        self, data_missing_for_sorting, ascending, sort_by_key
-    ):
-        super().test_sort_values_missing(
-            data_missing_for_sorting, ascending, sort_by_key
-        )
-
     @pytest.mark.xfail(reason="combine for JSONArray not supported")
     def test_combine_le(self, data_repeated):
         super().test_combine_le(data_repeated)
diff --git a/pandas/tests/extension/test_datetime.py b/pandas/tests/extension/test_datetime.py
index 15373527c871e..c5f6b0e16328c 100644
--- a/pandas/tests/extension/test_datetime.py
+++ b/pandas/tests/extension/test_datetime.py
@@ -24,9 +24,9 @@
 from pandas.tests.extension import base
 
 
-@pytest.fixture(params=["US/Central"])
-def dtype(request):
-    return DatetimeTZDtype(unit="ns", tz=request.param)
+@pytest.fixture
+def dtype():
+    return DatetimeTZDtype(unit="ns", tz="US/Central")
 
 
 @pytest.fixture
diff --git a/pandas/tests/frame/methods/test_asfreq.py b/pandas/tests/frame/methods/test_asfreq.py
index ef72ca1ac86b9..87d1745774487 100644
--- a/pandas/tests/frame/methods/test_asfreq.py
+++ b/pandas/tests/frame/methods/test_asfreq.py
@@ -19,10 +19,6 @@
 
 
 class TestAsFreq:
-    @pytest.fixture(params=["s", "ms", "us", "ns"])
-    def unit(self, request):
-        return request.param
-
     def test_asfreq2(self, frame_or_series):
         ts = frame_or_series(
             [0.0, 1.0, 2.0],
diff --git a/pandas/tests/frame/methods/test_sort_index.py b/pandas/tests/frame/methods/test_sort_index.py
index 49e292057e4dc..821b2e0d7a6da 100644
--- a/pandas/tests/frame/methods/test_sort_index.py
+++ b/pandas/tests/frame/methods/test_sort_index.py
@@ -927,7 +927,6 @@ def test_sort_index_na_position(self):
         result = df.sort_index(level=[0, 1], na_position="last")
         tm.assert_frame_equal(result, expected)
 
-    @pytest.mark.parametrize("ascending", [True, False])
     def test_sort_index_multiindex_sort_remaining(self, ascending):
         # GH #24247
         df = DataFrame(
diff --git a/pandas/tests/frame/methods/test_sort_values.py b/pandas/tests/frame/methods/test_sort_values.py
index f2f02058a534e..33adfcbc6f5ee 100644
--- a/pandas/tests/frame/methods/test_sort_values.py
+++ b/pandas/tests/frame/methods/test_sort_values.py
@@ -849,11 +849,6 @@ def sort_names(request):
     return request.param
 
 
-@pytest.fixture(params=[True, False])
-def ascending(request):
-    return request.param
-
-
 class TestSortValuesLevelAsStr:
     def test_sort_index_level_and_column_label(
         self, df_none, df_idx, sort_names, ascending, request
@@ -927,7 +922,6 @@ def test_sort_values_validate_ascending_for_value_error(self):
         with pytest.raises(ValueError, match=msg):
             df.sort_values(by="D", ascending="False")
 
-    @pytest.mark.parametrize("ascending", [False, 0, 1, True])
     def test_sort_values_validate_ascending_functional(self, ascending):
         df = DataFrame({"D": [23, 7, 21]})
         indexer = df["D"].argsort().values
diff --git a/pandas/tests/groupby/methods/test_rank.py b/pandas/tests/groupby/methods/test_rank.py
index a3b7da3fa836c..035fbbbdd3685 100644
--- a/pandas/tests/groupby/methods/test_rank.py
+++ b/pandas/tests/groupby/methods/test_rank.py
@@ -481,7 +481,6 @@ def test_rank_avg_even_vals(dtype, upper):
 
 
 @pytest.mark.parametrize("ties_method", ["average", "min", "max", "first", "dense"])
-@pytest.mark.parametrize("ascending", [True, False])
 @pytest.mark.parametrize("na_option", ["keep", "top", "bottom"])
 @pytest.mark.parametrize("pct", [True, False])
 @pytest.mark.parametrize(
@@ -510,7 +509,6 @@ def test_rank_object_dtype(ties_method, ascending, na_option, pct, vals):
 
 @pytest.mark.parametrize("na_option", [True, "bad", 1])
 @pytest.mark.parametrize("ties_method", ["average", "min", "max", "first", "dense"])
-@pytest.mark.parametrize("ascending", [True, False])
 @pytest.mark.parametrize("pct", [True, False])
 @pytest.mark.parametrize(
     "vals",
diff --git a/pandas/tests/groupby/methods/test_value_counts.py b/pandas/tests/groupby/methods/test_value_counts.py
index 538ed7f93f857..33da9cd965809 100644
--- a/pandas/tests/groupby/methods/test_value_counts.py
+++ b/pandas/tests/groupby/methods/test_value_counts.py
@@ -76,7 +76,6 @@ def seed_df(seed_nans, n, m):
 @pytest.mark.parametrize("bins", [None, [0, 5]], ids=repr)
 @pytest.mark.parametrize("isort", [True, False])
 @pytest.mark.parametrize("normalize, name", [(True, "proportion"), (False, "count")])
-@pytest.mark.parametrize("ascending", [True, False])
 def test_series_groupby_value_counts(
     seed_nans,
     num_rows,
diff --git a/pandas/tests/indexes/datetimes/test_formats.py b/pandas/tests/indexes/datetimes/test_formats.py
index b52eed8c509c6..f8b01f7985535 100644
--- a/pandas/tests/indexes/datetimes/test_formats.py
+++ b/pandas/tests/indexes/datetimes/test_formats.py
@@ -14,11 +14,6 @@
 import pandas._testing as tm
 
 
-@pytest.fixture(params=["s", "ms", "us", "ns"])
-def unit(request):
-    return request.param
-
-
 def test_get_values_for_csv():
     index = pd.date_range(freq="1D", periods=3, start="2017-01-01")
 
diff --git a/pandas/tests/resample/test_datetime_index.py b/pandas/tests/resample/test_datetime_index.py
index 80583f5d3c5f2..18629d1c5f2a5 100644
--- a/pandas/tests/resample/test_datetime_index.py
+++ b/pandas/tests/resample/test_datetime_index.py
@@ -51,11 +51,6 @@ def _static_values(index):
     return np.random.default_rng(2).random(len(index))
 
 
-@pytest.fixture(params=["s", "ms", "us", "ns"])
-def unit(request):
-    return request.param
-
-
 @pytest.fixture
 def simple_date_range_series():
     """
diff --git a/pandas/tests/reshape/merge/test_merge_asof.py b/pandas/tests/reshape/merge/test_merge_asof.py
index b656191cc739d..33502f576dd2f 100644
--- a/pandas/tests/reshape/merge/test_merge_asof.py
+++ b/pandas/tests/reshape/merge/test_merge_asof.py
@@ -18,14 +18,6 @@
 from pandas.core.reshape.merge import MergeError
 
 
-@pytest.fixture(params=["s", "ms", "us", "ns"])
-def unit(request):
-    """
-    Resolution for datetimelike dtypes.
-    """
-    return request.param
-
-
 class TestAsOfMerge:
     def prep_data(self, df, dedupe=False):
         if dedupe:
diff --git a/pandas/tests/series/methods/test_rank.py b/pandas/tests/series/methods/test_rank.py
index 24cf97c05c0a8..8a97c34318e71 100644
--- a/pandas/tests/series/methods/test_rank.py
+++ b/pandas/tests/series/methods/test_rank.py
@@ -248,7 +248,6 @@ def test_rank_tie_methods(self, ser, results, dtype):
         result = ser.rank(method=method)
         tm.assert_series_equal(result, Series(exp))
 
-    @pytest.mark.parametrize("ascending", [True, False])
     @pytest.mark.parametrize("method", ["average", "min", "max", "first", "dense"])
     @pytest.mark.parametrize("na_option", ["top", "bottom", "keep"])
     @pytest.mark.parametrize(
diff --git a/pandas/tests/series/methods/test_sort_values.py b/pandas/tests/series/methods/test_sort_values.py
index 4808272879071..00142c4d82327 100644
--- a/pandas/tests/series/methods/test_sort_values.py
+++ b/pandas/tests/series/methods/test_sort_values.py
@@ -204,7 +204,6 @@ def test_sort_values_validate_ascending_for_value_error(self):
         with pytest.raises(ValueError, match=msg):
             ser.sort_values(ascending="False")
 
-    @pytest.mark.parametrize("ascending", [False, 0, 1, True])
     def test_sort_values_validate_ascending_functional(self, ascending):
         # GH41634
         ser = Series([23, 7, 21])
diff --git a/pandas/tests/test_nanops.py b/pandas/tests/test_nanops.py
index 632d9783c7f81..6eac4822585dc 100644
--- a/pandas/tests/test_nanops.py
+++ b/pandas/tests/test_nanops.py
@@ -1103,10 +1103,6 @@ def prng(self):
 
 
 class TestDatetime64NaNOps:
-    @pytest.fixture(params=["s", "ms", "us", "ns"])
-    def unit(self, request):
-        return request.param
-
     # Enabling mean changes the behavior of DataFrame.mean
     # See https://github.com/pandas-dev/pandas/issues/24752
     def test_nanmean(self, unit):
diff --git a/pandas/tests/window/test_expanding.py b/pandas/tests/window/test_expanding.py
index e56d62e98d258..10d0afb5a2412 100644
--- a/pandas/tests/window/test_expanding.py
+++ b/pandas/tests/window/test_expanding.py
@@ -241,7 +241,6 @@ def test_expanding_skew_kurt_numerical_stability(method):
 @pytest.mark.parametrize("window", [1, 3, 10, 20])
 @pytest.mark.parametrize("method", ["min", "max", "average"])
 @pytest.mark.parametrize("pct", [True, False])
-@pytest.mark.parametrize("ascending", [True, False])
 @pytest.mark.parametrize("test_data", ["default", "duplicates", "nans"])
 def test_rank(window, method, pct, ascending, test_data):
     length = 20
diff --git a/pandas/tests/window/test_rolling.py b/pandas/tests/window/test_rolling.py
index e1362109c8157..a9a4a2a2bd991 100644
--- a/pandas/tests/window/test_rolling.py
+++ b/pandas/tests/window/test_rolling.py
@@ -1629,7 +1629,6 @@ def test_rolling_numeric_dtypes():
 @pytest.mark.parametrize("window", [1, 3, 10, 20])
 @pytest.mark.parametrize("method", ["min", "max", "average"])
 @pytest.mark.parametrize("pct", [True, False])
-@pytest.mark.parametrize("ascending", [True, False])
 @pytest.mark.parametrize("test_data", ["default", "duplicates", "nans"])
 def test_rank(window, method, pct, ascending, test_data):
     length = 20

From 3124ac508d40645ba786610a3f2121cb4c9918a1 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 14:26:21 -0800
Subject: [PATCH 18/26] Use shared rank_method fixture

---
 pandas/conftest.py                        |  8 +++++
 pandas/tests/frame/methods/test_rank.py   | 41 ++++++++++-------------
 pandas/tests/groupby/methods/test_rank.py | 12 +++----
 pandas/tests/series/methods/test_rank.py  | 20 ++++++-----
 4 files changed, 42 insertions(+), 39 deletions(-)

diff --git a/pandas/conftest.py b/pandas/conftest.py
index a32476f161863..dbfc0e9cab9bc 100644
--- a/pandas/conftest.py
+++ b/pandas/conftest.py
@@ -435,6 +435,14 @@ def ascending(request):
     return request.param
 
 
+@pytest.fixture(params=["average", "min", "max", "first", "dense"])
+def rank_method(request):
+    """
+    Fixture for 'rank' argument in rank.
+    """
+    return request.param
+
+
 # ----------------------------------------------------------------
 # Missing values & co.
 # ----------------------------------------------------------------
diff --git a/pandas/tests/frame/methods/test_rank.py b/pandas/tests/frame/methods/test_rank.py
index 8d7a0b373f5f8..1d0931f5982b7 100644
--- a/pandas/tests/frame/methods/test_rank.py
+++ b/pandas/tests/frame/methods/test_rank.py
@@ -31,13 +31,6 @@ class TestRank:
         "dense": np.array([1, 3, 4, 2, np.nan, 2, 1, 5, np.nan, 3]),
     }
 
-    @pytest.fixture(params=["average", "min", "max", "first", "dense"])
-    def method(self, request):
-        """
-        Fixture for trying all rank methods
-        """
-        return request.param
-
     def test_rank(self, float_frame):
         sp_stats = pytest.importorskip("scipy.stats")
 
@@ -225,8 +218,7 @@ def test_rank_axis(self):
         tm.assert_frame_equal(df.rank(axis=1), df.rank(axis="columns"))
 
     @pytest.mark.parametrize("ax", [0, 1])
-    @pytest.mark.parametrize("m", ["average", "min", "max", "first", "dense"])
-    def test_rank_methods_frame(self, ax, m):
+    def test_rank_methods_frame(self, ax, rank_method):
         sp_stats = pytest.importorskip("scipy.stats")
 
         xs = np.random.default_rng(2).integers(0, 21, (100, 26))
@@ -236,16 +228,19 @@ def test_rank_methods_frame(self, ax, m):
         for vals in [xs, xs + 1e6, xs * 1e-6]:
             df = DataFrame(vals, columns=cols)
 
-            result = df.rank(axis=ax, method=m)
+            result = df.rank(axis=ax, method=rank_method)
             sprank = np.apply_along_axis(
-                sp_stats.rankdata, ax, vals, m if m != "first" else "ordinal"
+                sp_stats.rankdata,
+                ax,
+                vals,
+                rank_method if rank_method != "first" else "ordinal",
             )
             sprank = sprank.astype(np.float64)
             expected = DataFrame(sprank, columns=cols).astype("float64")
             tm.assert_frame_equal(result, expected)
 
     @pytest.mark.parametrize("dtype", ["O", "f8", "i8"])
-    def test_rank_descending(self, method, dtype):
+    def test_rank_descending(self, rank_method, dtype):
         if "i" in dtype:
             df = self.df.dropna().astype(dtype)
         else:
@@ -255,18 +250,18 @@ def test_rank_descending(self, method, dtype):
         expected = (df.max() - df).rank()
         tm.assert_frame_equal(res, expected)
 
-        expected = (df.max() - df).rank(method=method)
+        expected = (df.max() - df).rank(method=rank_method)
 
         if dtype != "O":
-            res2 = df.rank(method=method, ascending=False, numeric_only=True)
+            res2 = df.rank(method=rank_method, ascending=False, numeric_only=True)
             tm.assert_frame_equal(res2, expected)
 
-        res3 = df.rank(method=method, ascending=False, numeric_only=False)
+        res3 = df.rank(method=rank_method, ascending=False, numeric_only=False)
         tm.assert_frame_equal(res3, expected)
 
     @pytest.mark.parametrize("axis", [0, 1])
     @pytest.mark.parametrize("dtype", [None, object])
-    def test_rank_2d_tie_methods(self, method, axis, dtype):
+    def test_rank_2d_tie_methods(self, rank_method, axis, dtype):
         df = self.df
 
         def _check2d(df, expected, method="average", axis=0):
@@ -276,14 +271,14 @@ def _check2d(df, expected, method="average", axis=0):
                 df = df.T
                 exp_df = exp_df.T
 
-            result = df.rank(method=method, axis=axis)
+            result = df.rank(method=rank_method, axis=axis)
             tm.assert_frame_equal(result, exp_df)
 
         frame = df if dtype is None else df.astype(dtype)
-        _check2d(frame, self.results[method], method=method, axis=axis)
+        _check2d(frame, self.results[rank_method], method=rank_method, axis=axis)
 
     @pytest.mark.parametrize(
-        "method,exp",
+        "rank_method,exp",
         [
             ("dense", [[1.0, 1.0, 1.0], [1.0, 0.5, 2.0 / 3], [1.0, 0.5, 1.0 / 3]]),
             (
@@ -312,11 +307,11 @@ def _check2d(df, expected, method="average", axis=0):
             ),
         ],
     )
-    def test_rank_pct_true(self, method, exp):
+    def test_rank_pct_true(self, rank_method, exp):
         # see gh-15630.
 
         df = DataFrame([[2012, 66, 3], [2012, 65, 2], [2012, 65, 1]])
-        result = df.rank(method=method, pct=True)
+        result = df.rank(method=rank_method, pct=True)
 
         expected = DataFrame(exp)
         tm.assert_frame_equal(result, expected)
@@ -454,10 +449,10 @@ def test_rank_both_inf(self):
         ],
     )
     def test_rank_inf_nans_na_option(
-        self, frame_or_series, method, na_option, ascending, expected
+        self, frame_or_series, rank_method, na_option, ascending, expected
     ):
         obj = frame_or_series([np.inf, np.nan, -np.inf])
-        result = obj.rank(method=method, na_option=na_option, ascending=ascending)
+        result = obj.rank(method=rank_method, na_option=na_option, ascending=ascending)
         expected = frame_or_series(expected)
         tm.assert_equal(result, expected)
 
diff --git a/pandas/tests/groupby/methods/test_rank.py b/pandas/tests/groupby/methods/test_rank.py
index 035fbbbdd3685..18869033d05c6 100644
--- a/pandas/tests/groupby/methods/test_rank.py
+++ b/pandas/tests/groupby/methods/test_rank.py
@@ -480,18 +480,17 @@ def test_rank_avg_even_vals(dtype, upper):
     tm.assert_frame_equal(result, exp_df)
 
 
-@pytest.mark.parametrize("ties_method", ["average", "min", "max", "first", "dense"])
 @pytest.mark.parametrize("na_option", ["keep", "top", "bottom"])
 @pytest.mark.parametrize("pct", [True, False])
 @pytest.mark.parametrize(
     "vals", [["bar", "bar", "foo", "bar", "baz"], ["bar", np.nan, "foo", np.nan, "baz"]]
 )
-def test_rank_object_dtype(ties_method, ascending, na_option, pct, vals):
+def test_rank_object_dtype(rank_method, ascending, na_option, pct, vals):
     df = DataFrame({"key": ["foo"] * 5, "val": vals})
     mask = df["val"].isna()
 
     gb = df.groupby("key")
-    res = gb.rank(method=ties_method, ascending=ascending, na_option=na_option, pct=pct)
+    res = gb.rank(method=rank_method, ascending=ascending, na_option=na_option, pct=pct)
 
     # construct our expected by using numeric values with the same ordering
     if mask.any():
@@ -501,14 +500,13 @@ def test_rank_object_dtype(ties_method, ascending, na_option, pct, vals):
 
     gb2 = df2.groupby("key")
     alt = gb2.rank(
-        method=ties_method, ascending=ascending, na_option=na_option, pct=pct
+        method=rank_method, ascending=ascending, na_option=na_option, pct=pct
     )
 
     tm.assert_frame_equal(res, alt)
 
 
 @pytest.mark.parametrize("na_option", [True, "bad", 1])
-@pytest.mark.parametrize("ties_method", ["average", "min", "max", "first", "dense"])
 @pytest.mark.parametrize("pct", [True, False])
 @pytest.mark.parametrize(
     "vals",
@@ -518,13 +516,13 @@ def test_rank_object_dtype(ties_method, ascending, na_option, pct, vals):
         [1, np.nan, 2, np.nan, 3],
     ],
 )
-def test_rank_naoption_raises(ties_method, ascending, na_option, pct, vals):
+def test_rank_naoption_raises(rank_method, ascending, na_option, pct, vals):
     df = DataFrame({"key": ["foo"] * 5, "val": vals})
     msg = "na_option must be one of 'keep', 'top', or 'bottom'"
 
     with pytest.raises(ValueError, match=msg):
         df.groupby("key").rank(
-            method=ties_method, ascending=ascending, na_option=na_option, pct=pct
+            method=rank_method, ascending=ascending, na_option=na_option, pct=pct
         )
 
 
diff --git a/pandas/tests/series/methods/test_rank.py b/pandas/tests/series/methods/test_rank.py
index 8a97c34318e71..4d48f290e6a44 100644
--- a/pandas/tests/series/methods/test_rank.py
+++ b/pandas/tests/series/methods/test_rank.py
@@ -248,7 +248,6 @@ def test_rank_tie_methods(self, ser, results, dtype):
         result = ser.rank(method=method)
         tm.assert_series_equal(result, Series(exp))
 
-    @pytest.mark.parametrize("method", ["average", "min", "max", "first", "dense"])
     @pytest.mark.parametrize("na_option", ["top", "bottom", "keep"])
     @pytest.mark.parametrize(
         "dtype, na_value, pos_inf, neg_inf",
@@ -266,11 +265,11 @@ def test_rank_tie_methods(self, ser, results, dtype):
         ],
     )
     def test_rank_tie_methods_on_infs_nans(
-        self, method, na_option, ascending, dtype, na_value, pos_inf, neg_inf
+        self, rank_method, na_option, ascending, dtype, na_value, pos_inf, neg_inf
     ):
         pytest.importorskip("scipy")
         if dtype == "float64[pyarrow]":
-            if method == "average":
+            if rank_method == "average":
                 exp_dtype = "float64[pyarrow]"
             else:
                 exp_dtype = "uint64[pyarrow]"
@@ -287,7 +286,7 @@ def test_rank_tie_methods_on_infs_nans(
             "first": ([1, 2, 3], [4, 5, 6], [7, 8, 9]),
             "dense": ([1, 1, 1], [2, 2, 2], [3, 3, 3]),
         }
-        ranks = exp_ranks[method]
+        ranks = exp_ranks[rank_method]
         if na_option == "top":
             order = [ranks[1], ranks[0], ranks[2]]
         elif na_option == "bottom":
@@ -296,7 +295,9 @@ def test_rank_tie_methods_on_infs_nans(
             order = [ranks[0], [np.nan] * chunk, ranks[1]]
         expected = order if ascending else order[::-1]
         expected = list(chain.from_iterable(expected))
-        result = iseries.rank(method=method, na_option=na_option, ascending=ascending)
+        result = iseries.rank(
+            method=rank_method, na_option=na_option, ascending=ascending
+        )
         tm.assert_series_equal(result, Series(expected, dtype=exp_dtype))
 
     def test_rank_desc_mix_nans_infs(self):
@@ -307,7 +308,6 @@ def test_rank_desc_mix_nans_infs(self):
         exp = Series([3, np.nan, 1, 4, 2], dtype="float64")
         tm.assert_series_equal(result, exp)
 
-    @pytest.mark.parametrize("method", ["average", "min", "max", "first", "dense"])
     @pytest.mark.parametrize(
         "op, value",
         [
@@ -316,7 +316,7 @@ def test_rank_desc_mix_nans_infs(self):
             [operator.mul, 1e-6],
         ],
     )
-    def test_rank_methods_series(self, method, op, value):
+    def test_rank_methods_series(self, rank_method, op, value):
         sp_stats = pytest.importorskip("scipy.stats")
 
         xs = np.random.default_rng(2).standard_normal(9)
@@ -326,8 +326,10 @@ def test_rank_methods_series(self, method, op, value):
         index = [chr(ord("a") + i) for i in range(len(xs))]
         vals = op(xs, value)
         ts = Series(vals, index=index)
-        result = ts.rank(method=method)
-        sprank = sp_stats.rankdata(vals, method if method != "first" else "ordinal")
+        result = ts.rank(method=rank_method)
+        sprank = sp_stats.rankdata(
+            vals, rank_method if rank_method != "first" else "ordinal"
+        )
         expected = Series(sprank, index=index).astype("float64")
         tm.assert_series_equal(result, expected)
 

From db80a7de9bda4c16ee9d8e48a76de0f24085c498 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 14:30:26 -0800
Subject: [PATCH 19/26] Use shared as_index fixture

---
 pandas/conftest.py                                | 8 ++++++++
 pandas/tests/extension/base/groupby.py            | 1 -
 pandas/tests/extension/test_categorical.py        | 1 -
 pandas/tests/extension/test_sparse.py             | 1 -
 pandas/tests/groupby/aggregate/test_numba.py      | 1 -
 pandas/tests/groupby/conftest.py                  | 5 -----
 pandas/tests/groupby/methods/test_describe.py     | 1 -
 pandas/tests/groupby/methods/test_nth.py          | 1 -
 pandas/tests/groupby/methods/test_size.py         | 1 -
 pandas/tests/groupby/methods/test_value_counts.py | 7 -------
 pandas/tests/groupby/test_groupby.py              | 1 -
 pandas/tests/groupby/test_reductions.py           | 1 -
 pandas/tests/groupby/transform/test_numba.py      | 1 -
 13 files changed, 8 insertions(+), 22 deletions(-)

diff --git a/pandas/conftest.py b/pandas/conftest.py
index dbfc0e9cab9bc..c9339739774f1 100644
--- a/pandas/conftest.py
+++ b/pandas/conftest.py
@@ -443,6 +443,14 @@ def rank_method(request):
     return request.param
 
 
+@pytest.fixture(params=[True, False])
+def as_index(request):
+    """
+    Fixture for 'as_index' argument in groupby.
+    """
+    return request.param
+
+
 # ----------------------------------------------------------------
 # Missing values & co.
 # ----------------------------------------------------------------
diff --git a/pandas/tests/extension/base/groupby.py b/pandas/tests/extension/base/groupby.py
index 75628ea177fc2..9f38246d1a317 100644
--- a/pandas/tests/extension/base/groupby.py
+++ b/pandas/tests/extension/base/groupby.py
@@ -34,7 +34,6 @@ def test_grouping_grouper(self, data_for_grouping):
         tm.assert_numpy_array_equal(gr1.grouping_vector, df.A.values)
         tm.assert_extension_array_equal(gr2.grouping_vector, data_for_grouping)
 
-    @pytest.mark.parametrize("as_index", [True, False])
     def test_groupby_extension_agg(self, as_index, data_for_grouping):
         df = pd.DataFrame({"A": [1, 1, 2, 2, 3, 3, 1, 4], "B": data_for_grouping})
 
diff --git a/pandas/tests/extension/test_categorical.py b/pandas/tests/extension/test_categorical.py
index 74a5110de2c8e..7598aca10bad4 100644
--- a/pandas/tests/extension/test_categorical.py
+++ b/pandas/tests/extension/test_categorical.py
@@ -183,7 +183,6 @@ def test_array_repr(self, data, size):
         super().test_array_repr(data, size)
 
     @pytest.mark.xfail(reason="TBD")
-    @pytest.mark.parametrize("as_index", [True, False])
     def test_groupby_extension_agg(self, as_index, data_for_grouping):
         super().test_groupby_extension_agg(as_index, data_for_grouping)
 
diff --git a/pandas/tests/extension/test_sparse.py b/pandas/tests/extension/test_sparse.py
index d0f55dde998b1..03f179fdd261e 100644
--- a/pandas/tests/extension/test_sparse.py
+++ b/pandas/tests/extension/test_sparse.py
@@ -486,7 +486,6 @@ def test_array_repr(self, data, size):
         super().test_array_repr(data, size)
 
     @pytest.mark.xfail(reason="result does not match expected")
-    @pytest.mark.parametrize("as_index", [True, False])
     def test_groupby_extension_agg(self, as_index, data_for_grouping):
         super().test_groupby_extension_agg(as_index, data_for_grouping)
 
diff --git a/pandas/tests/groupby/aggregate/test_numba.py b/pandas/tests/groupby/aggregate/test_numba.py
index ee694129f7118..89404a9bd09a3 100644
--- a/pandas/tests/groupby/aggregate/test_numba.py
+++ b/pandas/tests/groupby/aggregate/test_numba.py
@@ -53,7 +53,6 @@ def incorrect_function(values, index):
 # Filter warnings when parallel=True and the function can't be parallelized by Numba
 @pytest.mark.parametrize("jit", [True, False])
 @pytest.mark.parametrize("pandas_obj", ["Series", "DataFrame"])
-@pytest.mark.parametrize("as_index", [True, False])
 def test_numba_vs_cython(jit, pandas_obj, nogil, parallel, nopython, as_index):
     pytest.importorskip("numba")
 
diff --git a/pandas/tests/groupby/conftest.py b/pandas/tests/groupby/conftest.py
index 187076a7bac0d..1f1401b8dcce3 100644
--- a/pandas/tests/groupby/conftest.py
+++ b/pandas/tests/groupby/conftest.py
@@ -13,11 +13,6 @@
 )
 
 
-@pytest.fixture(params=[True, False])
-def as_index(request):
-    return request.param
-
-
 @pytest.fixture
 def df():
     return DataFrame(
diff --git a/pandas/tests/groupby/methods/test_describe.py b/pandas/tests/groupby/methods/test_describe.py
index a2440e09dfc02..f27e99809176c 100644
--- a/pandas/tests/groupby/methods/test_describe.py
+++ b/pandas/tests/groupby/methods/test_describe.py
@@ -149,7 +149,6 @@ def test_frame_describe_unstacked_format():
     "indexing past lexsort depth may impact performance:"
     "pandas.errors.PerformanceWarning"
 )
-@pytest.mark.parametrize("as_index", [True, False])
 @pytest.mark.parametrize("keys", [["a1"], ["a1", "a2"]])
 def test_describe_with_duplicate_output_column_names(as_index, keys):
     # GH 35314
diff --git a/pandas/tests/groupby/methods/test_nth.py b/pandas/tests/groupby/methods/test_nth.py
index a8ed9e9d52021..52d63cb720485 100644
--- a/pandas/tests/groupby/methods/test_nth.py
+++ b/pandas/tests/groupby/methods/test_nth.py
@@ -529,7 +529,6 @@ def test_nth_multi_index_as_expected():
     ],
 )
 @pytest.mark.parametrize("columns", [None, [], ["A"], ["B"], ["A", "B"]])
-@pytest.mark.parametrize("as_index", [True, False])
 def test_groupby_head_tail(op, n, expected_rows, columns, as_index):
     df = DataFrame([[1, 2], [1, 4], [5, 6]], columns=["A", "B"])
     g = df.groupby("A", as_index=as_index)
diff --git a/pandas/tests/groupby/methods/test_size.py b/pandas/tests/groupby/methods/test_size.py
index 92a277d8014d4..fd55ceedd1083 100644
--- a/pandas/tests/groupby/methods/test_size.py
+++ b/pandas/tests/groupby/methods/test_size.py
@@ -83,7 +83,6 @@ def test_size_period_index():
     tm.assert_series_equal(result, ser)
 
 
-@pytest.mark.parametrize("as_index", [True, False])
 def test_size_on_categorical(as_index):
     df = DataFrame([[1, 1], [2, 2]], columns=["A", "B"])
     df["A"] = df["A"].astype("category")
diff --git a/pandas/tests/groupby/methods/test_value_counts.py b/pandas/tests/groupby/methods/test_value_counts.py
index 33da9cd965809..5c9f7febe32b3 100644
--- a/pandas/tests/groupby/methods/test_value_counts.py
+++ b/pandas/tests/groupby/methods/test_value_counts.py
@@ -292,7 +292,6 @@ def _frame_value_counts(df, keys, normalize, sort, ascending):
         (True, False),
     ],
 )
-@pytest.mark.parametrize("as_index", [True, False])
 @pytest.mark.parametrize("frame", [True, False])
 def test_against_frame_and_seriesgroupby(
     education_df, groupby, normalize, name, sort, ascending, as_index, frame, request
@@ -580,7 +579,6 @@ def test_data_frame_value_counts_dropna(
     tm.assert_series_equal(result_frame_groupby, expected)
 
 
-@pytest.mark.parametrize("as_index", [False, True])
 @pytest.mark.parametrize("observed", [False, True])
 @pytest.mark.parametrize(
     "normalize, name, expected_data",
@@ -690,7 +688,6 @@ def assert_categorical_single_grouper(
         tm.assert_frame_equal(result, expected)
 
 
-@pytest.mark.parametrize("as_index", [True, False])
 @pytest.mark.parametrize(
     "normalize, name, expected_data",
     [
@@ -748,7 +745,6 @@ def test_categorical_single_grouper_observed_true(
     )
 
 
-@pytest.mark.parametrize("as_index", [True, False])
 @pytest.mark.parametrize(
     "normalize, name, expected_data",
     [
@@ -835,7 +831,6 @@ def test_categorical_single_grouper_observed_false(
     )
 
 
-@pytest.mark.parametrize("as_index", [True, False])
 @pytest.mark.parametrize(
     "observed, expected_index",
     [
@@ -921,7 +916,6 @@ def test_categorical_multiple_groupers(
         tm.assert_frame_equal(result, expected)
 
 
-@pytest.mark.parametrize("as_index", [False, True])
 @pytest.mark.parametrize("observed", [False, True])
 @pytest.mark.parametrize(
     "normalize, name, expected_data",
@@ -1030,7 +1024,6 @@ def test_mixed_groupings(normalize, expected_label, expected_values):
         ("level", list("abcd") + ["level_1"], ["a", None, "d", "b", "c", "level_1"]),
     ],
 )
-@pytest.mark.parametrize("as_index", [False, True])
 def test_column_label_duplicates(test, columns, expected_names, as_index):
     # GH 44992
     # Test for duplicate input column labels and generated duplicate labels
diff --git a/pandas/tests/groupby/test_groupby.py b/pandas/tests/groupby/test_groupby.py
index fce7caa90cce4..2ac1f4faa998e 100644
--- a/pandas/tests/groupby/test_groupby.py
+++ b/pandas/tests/groupby/test_groupby.py
@@ -295,7 +295,6 @@ def f(x, q=None, axis=0):
         tm.assert_frame_equal(apply_result, expected, check_names=False)
 
 
-@pytest.mark.parametrize("as_index", [True, False])
 def test_pass_args_kwargs_duplicate_columns(tsframe, as_index):
     # go through _aggregate_frame with self.axis == 0 and duplicate columns
     tsframe.columns = ["A", "B", "A", "C"]
diff --git a/pandas/tests/groupby/test_reductions.py b/pandas/tests/groupby/test_reductions.py
index ba73bf3b9908a..bb5ea233c27be 100644
--- a/pandas/tests/groupby/test_reductions.py
+++ b/pandas/tests/groupby/test_reductions.py
@@ -635,7 +635,6 @@ def test_max_nan_bug():
 
 
 @pytest.mark.slow
-@pytest.mark.parametrize("as_index", [True, False])
 @pytest.mark.parametrize("with_nan", [True, False])
 @pytest.mark.parametrize("keys", [["joe"], ["joe", "jim"]])
 def test_series_groupby_nunique(sort, dropna, as_index, with_nan, keys):
diff --git a/pandas/tests/groupby/transform/test_numba.py b/pandas/tests/groupby/transform/test_numba.py
index 61fcc930f116a..af11dae0aabfe 100644
--- a/pandas/tests/groupby/transform/test_numba.py
+++ b/pandas/tests/groupby/transform/test_numba.py
@@ -51,7 +51,6 @@ def incorrect_function(values, index):
 # Filter warnings when parallel=True and the function can't be parallelized by Numba
 @pytest.mark.parametrize("jit", [True, False])
 @pytest.mark.parametrize("pandas_obj", ["Series", "DataFrame"])
-@pytest.mark.parametrize("as_index", [True, False])
 def test_numba_vs_cython(jit, pandas_obj, nogil, parallel, nopython, as_index):
     pytest.importorskip("numba")
 

From 839f5ad8562084cd4b372ad9fc656a9c8b4047be Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 14:41:44 -0800
Subject: [PATCH 20/26] Share more fixtures

---
 pandas/tests/indexes/numeric/test_numeric.py | 6 +++---
 pandas/tests/indexing/test_loc.py            | 6 +++---
 pandas/tests/io/excel/test_xlrd.py           | 6 +++---
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/pandas/tests/indexes/numeric/test_numeric.py b/pandas/tests/indexes/numeric/test_numeric.py
index 7ce55db6c0bbc..1a2fefc33f157 100644
--- a/pandas/tests/indexes/numeric/test_numeric.py
+++ b/pandas/tests/indexes/numeric/test_numeric.py
@@ -237,9 +237,9 @@ def test_logical_compat(self, simple_index):
 
 
 class TestNumericInt:
-    @pytest.fixture(params=[np.int64, np.int32, np.int16, np.int8, np.uint64])
-    def dtype(self, request):
-        return request.param
+    @pytest.fixture
+    def dtype(self, any_int_numpy_dtype):
+        return np.dtype(any_int_numpy_dtype)
 
     @pytest.fixture
     def simple_index(self, dtype):
diff --git a/pandas/tests/indexing/test_loc.py b/pandas/tests/indexing/test_loc.py
index ce7dde3c4cb42..b9e28e8e0fcac 100644
--- a/pandas/tests/indexing/test_loc.py
+++ b/pandas/tests/indexing/test_loc.py
@@ -1687,10 +1687,10 @@ def test_loc_setitem_numpy_frame_categorical_value(self):
 
 
 class TestLocWithEllipsis:
-    @pytest.fixture(params=[tm.loc, tm.iloc])
-    def indexer(self, request):
+    @pytest.fixture
+    def indexer(self, indexer_li):
         # Test iloc while we're here
-        return request.param
+        return indexer_li
 
     @pytest.fixture
     def obj(self, series_with_simple_index, frame_or_series):
diff --git a/pandas/tests/io/excel/test_xlrd.py b/pandas/tests/io/excel/test_xlrd.py
index 6d5008ca9ee68..c49cbaf7fb26c 100644
--- a/pandas/tests/io/excel/test_xlrd.py
+++ b/pandas/tests/io/excel/test_xlrd.py
@@ -12,14 +12,14 @@
 xlrd = pytest.importorskip("xlrd")
 
 
-@pytest.fixture(params=[".xls"])
-def read_ext_xlrd(request):
+@pytest.fixture
+def read_ext_xlrd():
     """
     Valid extensions for reading Excel files with xlrd.
 
     Similar to read_ext, but excludes .ods, .xlsb, and for xlrd>2 .xlsx, .xlsm
     """
-    return request.param
+    return ".xls"
 
 
 def test_read_xlrd_book(read_ext_xlrd, datapath):

From fa876fb108c0cb39423074c5f4d5708d2d14fdbc Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 14:45:03 -0800
Subject: [PATCH 21/26] Reuse orient fixture

---
 pandas/tests/io/json/test_pandas.py | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/pandas/tests/io/json/test_pandas.py b/pandas/tests/io/json/test_pandas.py
index 58a1e51d31b74..9d608165ede6c 100644
--- a/pandas/tests/io/json/test_pandas.py
+++ b/pandas/tests/io/json/test_pandas.py
@@ -2026,9 +2026,6 @@ def test_json_uint64(self):
         result = df.to_json(orient="split")
         assert result == expected
 
-    @pytest.mark.parametrize(
-        "orient", ["split", "records", "values", "index", "columns"]
-    )
     def test_read_json_dtype_backend(
         self, string_storage, dtype_backend, orient, using_infer_string
     ):

From c31b95f6e7111badc453e6496aa4e8ad1772679d Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 14:51:26 -0800
Subject: [PATCH 22/26] Use shared cache fixture

---
 pandas/conftest.py                         |  8 ++++++++
 pandas/tests/io/parser/test_parse_dates.py | 12 +++++-------
 pandas/tests/tools/test_to_datetime.py     | 10 ----------
 3 files changed, 13 insertions(+), 17 deletions(-)

diff --git a/pandas/conftest.py b/pandas/conftest.py
index c9339739774f1..44bb3360e824e 100644
--- a/pandas/conftest.py
+++ b/pandas/conftest.py
@@ -451,6 +451,14 @@ def as_index(request):
     return request.param
 
 
+@pytest.fixture(params=[True, False])
+def cache(request):
+    """
+    Fixture for 'cache' argument in to_datetime.
+    """
+    return request.param
+
+
 # ----------------------------------------------------------------
 # Missing values & co.
 # ----------------------------------------------------------------
diff --git a/pandas/tests/io/parser/test_parse_dates.py b/pandas/tests/io/parser/test_parse_dates.py
index d8f362039ba13..700dcde336cd1 100644
--- a/pandas/tests/io/parser/test_parse_dates.py
+++ b/pandas/tests/io/parser/test_parse_dates.py
@@ -1326,9 +1326,8 @@ def test_read_with_parse_dates_invalid_type(all_parsers, parse_dates):
         parser.read_csv(StringIO(data), parse_dates=(1,))
 
 
-@pytest.mark.parametrize("cache_dates", [True, False])
 @pytest.mark.parametrize("value", ["nan", ""])
-def test_bad_date_parse(all_parsers, cache_dates, value):
+def test_bad_date_parse(all_parsers, cache, value):
     # if we have an invalid date make sure that we handle this with
     # and w/o the cache properly
     parser = all_parsers
@@ -1339,13 +1338,12 @@ def test_bad_date_parse(all_parsers, cache_dates, value):
         header=None,
         names=["foo", "bar"],
         parse_dates=["foo"],
-        cache_dates=cache_dates,
+        cache_dates=cache,
     )
 
 
-@pytest.mark.parametrize("cache_dates", [True, False])
 @pytest.mark.parametrize("value", ["0"])
-def test_bad_date_parse_with_warning(all_parsers, cache_dates, value):
+def test_bad_date_parse_with_warning(all_parsers, cache, value):
     # if we have an invalid date make sure that we handle this with
     # and w/o the cache properly.
     parser = all_parsers
@@ -1357,7 +1355,7 @@ def test_bad_date_parse_with_warning(all_parsers, cache_dates, value):
         # TODO: parse dates directly in pyarrow, see
         # https://github.com/pandas-dev/pandas/issues/48017
         warn = None
-    elif cache_dates:
+    elif cache:
         # Note: warning is not raised if 'cache_dates', because here there is only a
         # single unique date and hence no risk of inconsistent parsing.
         warn = None
@@ -1370,7 +1368,7 @@ def test_bad_date_parse_with_warning(all_parsers, cache_dates, value):
         header=None,
         names=["foo", "bar"],
         parse_dates=["foo"],
-        cache_dates=cache_dates,
+        cache_dates=cache,
         raise_on_extra_warnings=False,
     )
 
diff --git a/pandas/tests/tools/test_to_datetime.py b/pandas/tests/tools/test_to_datetime.py
index 0ce1f7b0ff20e..adcb4fe76abe3 100644
--- a/pandas/tests/tools/test_to_datetime.py
+++ b/pandas/tests/tools/test_to_datetime.py
@@ -62,14 +62,6 @@
 )
 
 
-@pytest.fixture(params=[True, False])
-def cache(request):
-    """
-    cache keyword to pass to to_datetime.
-    """
-    return request.param
-
-
 class TestTimeConversionFormats:
     def test_to_datetime_readonly(self, writable):
         # GH#34857
@@ -1585,7 +1577,6 @@ def test_convert_object_to_datetime_with_cache(
         )
         tm.assert_series_equal(result_series, expected_series)
 
-    @pytest.mark.parametrize("cache", [True, False])
     @pytest.mark.parametrize(
         "input",
         [
@@ -3597,7 +3588,6 @@ def test_empty_string_datetime_coerce__unit():
     tm.assert_index_equal(expected, result)
 
 
-@pytest.mark.parametrize("cache", [True, False])
 def test_to_datetime_monotonic_increasing_index(cache):
     # GH28238
     cstart = start_caching_at

From 07a9a29d3acd4a4ffdb33693f392ebbcd92a4724 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 15:01:46 -0800
Subject: [PATCH 23/26] Move nogil, parallel, nopython to top level

---
 pandas/conftest.py               | 28 ++++++++++++++++++++++++++++
 pandas/tests/groupby/conftest.py | 22 ----------------------
 pandas/tests/window/conftest.py  | 22 ----------------------
 3 files changed, 28 insertions(+), 44 deletions(-)

diff --git a/pandas/conftest.py b/pandas/conftest.py
index 44bb3360e824e..b6a7043a44c7a 100644
--- a/pandas/conftest.py
+++ b/pandas/conftest.py
@@ -459,6 +459,34 @@ def cache(request):
     return request.param
 
 
+@pytest.fixture(params=[True, False])
+def parallel(request):
+    """
+    Fixture for parallel keyword argument for numba.jit.
+    """
+    return request.param
+
+
+# Can parameterize nogil & nopython over True | False, but limiting per
+# https://github.com/pandas-dev/pandas/pull/41971#issuecomment-860607472
+
+
+@pytest.fixture(params=[False])
+def nogil(request):
+    """
+    Fixture for nogil keyword argument for numba.jit.
+    """
+    return request.param
+
+
+@pytest.fixture(params=[True])
+def nopython(request):
+    """
+    Fixture for nopython keyword argument for numba.jit.
+    """
+    return request.param
+
+
 # ----------------------------------------------------------------
 # Missing values & co.
 # ----------------------------------------------------------------
diff --git a/pandas/tests/groupby/conftest.py b/pandas/tests/groupby/conftest.py
index 1f1401b8dcce3..331dbd85e0f36 100644
--- a/pandas/tests/groupby/conftest.py
+++ b/pandas/tests/groupby/conftest.py
@@ -133,28 +133,6 @@ def groupby_func(request):
     return request.param
 
 
-@pytest.fixture(params=[True, False])
-def parallel(request):
-    """parallel keyword argument for numba.jit"""
-    return request.param
-
-
-# Can parameterize nogil & nopython over True | False, but limiting per
-# https://github.com/pandas-dev/pandas/pull/41971#issuecomment-860607472
-
-
-@pytest.fixture(params=[False])
-def nogil(request):
-    """nogil keyword argument for numba.jit"""
-    return request.param
-
-
-@pytest.fixture(params=[True])
-def nopython(request):
-    """nopython keyword argument for numba.jit"""
-    return request.param
-
-
 @pytest.fixture(
     params=[
         ("mean", {}),
diff --git a/pandas/tests/window/conftest.py b/pandas/tests/window/conftest.py
index 73ab470ab97a7..fe873b3b74254 100644
--- a/pandas/tests/window/conftest.py
+++ b/pandas/tests/window/conftest.py
@@ -50,28 +50,6 @@ def min_periods(request):
     return request.param
 
 
-@pytest.fixture(params=[True, False])
-def parallel(request):
-    """parallel keyword argument for numba.jit"""
-    return request.param
-
-
-# Can parameterize nogil & nopython over True | False, but limiting per
-# https://github.com/pandas-dev/pandas/pull/41971#issuecomment-860607472
-
-
-@pytest.fixture(params=[False])
-def nogil(request):
-    """nogil keyword argument for numba.jit"""
-    return request.param
-
-
-@pytest.fixture(params=[True])
-def nopython(request):
-    """nopython keyword argument for numba.jit"""
-    return request.param
-
-
 @pytest.fixture(params=[True, False])
 def adjust(request):
     """adjust keyword argument for ewm"""

From e5859c8452b6afd7f9eba6d92b60697c4b296b09 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 15:02:38 -0800
Subject: [PATCH 24/26] Use top level center

---
 pandas/tests/window/test_rolling.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/pandas/tests/window/test_rolling.py b/pandas/tests/window/test_rolling.py
index a9a4a2a2bd991..19c24f1c5b189 100644
--- a/pandas/tests/window/test_rolling.py
+++ b/pandas/tests/window/test_rolling.py
@@ -669,7 +669,6 @@ def test_rolling_datetime(axis, tz_naive_fixture):
     tm.assert_frame_equal(result, expected)
 
 
-@pytest.mark.parametrize("center", [True, False])
 def test_rolling_window_as_string(center):
     # see gh-22590
     date_today = datetime.now()

From 2fb836565bd7402d6be51b41034bbbb26542b5f4 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 15:34:15 -0800
Subject: [PATCH 25/26] Reuse more fixtures

---
 pandas/tests/apply/test_str.py                    |  8 +++-----
 pandas/tests/arithmetic/test_datetime64.py        |  4 ----
 pandas/tests/arrays/boolean/test_reduction.py     |  1 -
 pandas/tests/arrays/categorical/test_algos.py     |  1 -
 pandas/tests/arrays/categorical/test_api.py       |  1 -
 pandas/tests/arrays/categorical/test_astype.py    |  6 ++----
 .../tests/arrays/categorical/test_constructors.py |  2 --
 pandas/tests/arrays/categorical/test_dtypes.py    |  1 -
 .../tests/arrays/datetimes/test_constructors.py   |  1 -
 pandas/tests/arrays/integer/test_dtypes.py        |  2 --
 pandas/tests/base/test_unique.py                  |  1 -
 pandas/tests/base/test_value_counts.py            |  1 -
 pandas/tests/dtypes/test_dtypes.py                | 15 +++++++--------
 pandas/tests/extension/base/methods.py            |  1 -
 pandas/tests/extension/base/setitem.py            |  5 ++---
 pandas/tests/extension/decimal/test_decimal.py    |  3 +--
 pandas/tests/extension/test_arrow.py              |  1 -
 pandas/tests/frame/methods/test_astype.py         |  5 ++---
 pandas/tests/groupby/test_apply.py                |  2 --
 pandas/tests/groupby/test_groupby_dropna.py       |  1 -
 pandas/tests/groupby/test_missing.py              |  1 -
 .../tests/indexes/datetimes/methods/test_snap.py  |  1 -
 pandas/tests/indexes/test_datetimelike.py         |  1 -
 pandas/tests/interchange/test_impl.py             |  1 -
 pandas/tests/io/json/test_pandas.py               |  1 -
 pandas/tests/resample/test_timedelta.py           |  1 -
 pandas/tests/reshape/test_pivot.py                |  1 -
 .../tests/scalar/timedelta/methods/test_round.py  |  1 -
 .../scalar/timestamp/methods/test_normalize.py    |  1 -
 .../scalar/timestamp/methods/test_replace.py      |  2 --
 .../tests/scalar/timestamp/methods/test_round.py  |  2 --
 .../scalar/timestamp/methods/test_tz_localize.py  |  4 ----
 .../tests/tseries/frequencies/test_inference.py   |  1 -
 .../tests/tseries/offsets/test_business_hour.py   |  1 -
 pandas/tests/window/test_rolling.py               |  1 -
 35 files changed, 17 insertions(+), 65 deletions(-)

diff --git a/pandas/tests/apply/test_str.py b/pandas/tests/apply/test_str.py
index 17e8322dc40e1..4b3c86378734a 100644
--- a/pandas/tests/apply/test_str.py
+++ b/pandas/tests/apply/test_str.py
@@ -43,14 +43,12 @@ def test_apply_with_string_funcs(request, float_frame, func, args, kwds, how):
     tm.assert_series_equal(result, expected)
 
 
-@pytest.mark.parametrize("arg", ["sum", "mean", "min", "max", "std"])
-def test_with_string_args(datetime_series, arg):
-    result = datetime_series.apply(arg)
-    expected = getattr(datetime_series, arg)()
+def test_with_string_args(datetime_series, all_numeric_reductions):
+    result = datetime_series.apply(all_numeric_reductions)
+    expected = getattr(datetime_series, all_numeric_reductions)()
     assert result == expected
 
 
-@pytest.mark.parametrize("op", ["mean", "median", "std", "var"])
 @pytest.mark.parametrize("how", ["agg", "apply"])
 def test_apply_np_reducer(op, how):
     # GH 39116
diff --git a/pandas/tests/arithmetic/test_datetime64.py b/pandas/tests/arithmetic/test_datetime64.py
index dbff88dc6f4f6..b4e8d09c18163 100644
--- a/pandas/tests/arithmetic/test_datetime64.py
+++ b/pandas/tests/arithmetic/test_datetime64.py
@@ -1221,7 +1221,6 @@ class TestDatetime64DateOffsetArithmetic:
     # Tick DateOffsets
 
     # TODO: parametrize over timezone?
-    @pytest.mark.parametrize("unit", ["s", "ms", "us", "ns"])
     def test_dt64arr_series_add_tick_DateOffset(self, box_with_array, unit):
         # GH#4532
         # operate with pd.offsets
@@ -1311,7 +1310,6 @@ def test_dti_add_tick_tzaware(self, tz_aware_fixture, box_with_array):
     # -------------------------------------------------------------
     # RelativeDelta DateOffsets
 
-    @pytest.mark.parametrize("unit", ["s", "ms", "us", "ns"])
     def test_dt64arr_add_sub_relativedelta_offsets(self, box_with_array, unit):
         # GH#10699
         vec = DatetimeIndex(
@@ -1422,7 +1420,6 @@ def test_dt64arr_add_sub_relativedelta_offsets(self, box_with_array, unit):
     )
     @pytest.mark.parametrize("normalize", [True, False])
     @pytest.mark.parametrize("n", [0, 5])
-    @pytest.mark.parametrize("unit", ["s", "ms", "us", "ns"])
     @pytest.mark.parametrize("tz", [None, "US/Central"])
     def test_dt64arr_add_sub_DateOffsets(
         self, box_with_array, n, normalize, cls_and_kwargs, unit, tz
@@ -2356,7 +2353,6 @@ def test_dti_addsub_object_arraylike(
 
 @pytest.mark.parametrize("years", [-1, 0, 1])
 @pytest.mark.parametrize("months", [-2, 0, 2])
-@pytest.mark.parametrize("unit", ["s", "ms", "us", "ns"])
 def test_shift_months(years, months, unit):
     dti = DatetimeIndex(
         [
diff --git a/pandas/tests/arrays/boolean/test_reduction.py b/pandas/tests/arrays/boolean/test_reduction.py
index dd8c3eda9ed05..7071c6f8844e4 100644
--- a/pandas/tests/arrays/boolean/test_reduction.py
+++ b/pandas/tests/arrays/boolean/test_reduction.py
@@ -43,7 +43,6 @@ def test_any_all(values, exp_any, exp_all, exp_any_noskip, exp_all_noskip):
         assert np.all(a.all()) is exp_all
 
 
-@pytest.mark.parametrize("dropna", [True, False])
 def test_reductions_return_types(dropna, data, all_numeric_reductions):
     op = all_numeric_reductions
     s = pd.Series(data)
diff --git a/pandas/tests/arrays/categorical/test_algos.py b/pandas/tests/arrays/categorical/test_algos.py
index d4c19a4970135..69c3364c7e98e 100644
--- a/pandas/tests/arrays/categorical/test_algos.py
+++ b/pandas/tests/arrays/categorical/test_algos.py
@@ -5,7 +5,6 @@
 import pandas._testing as tm
 
 
-@pytest.mark.parametrize("ordered", [True, False])
 @pytest.mark.parametrize("categories", [["b", "a", "c"], ["a", "b", "c", "d"]])
 def test_factorize(categories, ordered):
     cat = pd.Categorical(
diff --git a/pandas/tests/arrays/categorical/test_api.py b/pandas/tests/arrays/categorical/test_api.py
index b4215b4a6fe21..58411b00f92e7 100644
--- a/pandas/tests/arrays/categorical/test_api.py
+++ b/pandas/tests/arrays/categorical/test_api.py
@@ -301,7 +301,6 @@ def test_set_categories(self):
             (["a", "b", "c"], ["a", "b"], ["d", "e"]),
         ],
     )
-    @pytest.mark.parametrize("ordered", [True, False])
     def test_set_categories_many(self, values, categories, new_categories, ordered):
         c = Categorical(values, categories)
         expected = Categorical(values, new_categories, ordered)
diff --git a/pandas/tests/arrays/categorical/test_astype.py b/pandas/tests/arrays/categorical/test_astype.py
index a2a53af6ab1ad..7cfd8ec8dfadf 100644
--- a/pandas/tests/arrays/categorical/test_astype.py
+++ b/pandas/tests/arrays/categorical/test_astype.py
@@ -81,7 +81,6 @@ def test_astype_str_int_categories_to_nullable_float(self):
         expected = array(codes, dtype="Float64") / 2
         tm.assert_extension_array_equal(res, expected)
 
-    @pytest.mark.parametrize("ordered", [True, False])
     def test_astype(self, ordered):
         # string
         cat = Categorical(list("abbaaccc"), ordered=ordered)
@@ -108,11 +107,10 @@ def test_astype(self, ordered):
         tm.assert_numpy_array_equal(result, expected)
 
     @pytest.mark.parametrize("dtype_ordered", [True, False])
-    @pytest.mark.parametrize("cat_ordered", [True, False])
-    def test_astype_category(self, dtype_ordered, cat_ordered):
+    def test_astype_category(self, dtype_ordered, ordered):
         # GH#10696/GH#18593
         data = list("abcaacbab")
-        cat = Categorical(data, categories=list("bac"), ordered=cat_ordered)
+        cat = Categorical(data, categories=list("bac"), ordered=ordered)
 
         # standard categories
         dtype = CategoricalDtype(ordered=dtype_ordered)
diff --git a/pandas/tests/arrays/categorical/test_constructors.py b/pandas/tests/arrays/categorical/test_constructors.py
index 373f1c95463fc..03678fb64d3e9 100644
--- a/pandas/tests/arrays/categorical/test_constructors.py
+++ b/pandas/tests/arrays/categorical/test_constructors.py
@@ -437,7 +437,6 @@ def test_constructor_dtype_and_others_raises(self):
             Categorical(["a", "b"], ordered=False, dtype=dtype)
 
     @pytest.mark.parametrize("categories", [None, ["a", "b"], ["a", "c"]])
-    @pytest.mark.parametrize("ordered", [True, False])
     def test_constructor_str_category(self, categories, ordered):
         result = Categorical(
             ["a", "b"], categories=categories, ordered=ordered, dtype="category"
@@ -683,7 +682,6 @@ def test_from_inferred_categories_coerces(self):
         expected = Categorical([1, 1, 2, np.nan])
         tm.assert_categorical_equal(result, expected)
 
-    @pytest.mark.parametrize("ordered", [None, True, False])
     def test_construction_with_ordered(self, ordered):
         # GH 9347, 9190
         cat = Categorical([0, 1, 2], ordered=ordered)
diff --git a/pandas/tests/arrays/categorical/test_dtypes.py b/pandas/tests/arrays/categorical/test_dtypes.py
index 525663cad1745..f2f2851c22794 100644
--- a/pandas/tests/arrays/categorical/test_dtypes.py
+++ b/pandas/tests/arrays/categorical/test_dtypes.py
@@ -83,7 +83,6 @@ def test_set_dtype_new_categories(self):
             (["a", "b", "c"], ["a", "b"], ["d", "e"]),
         ],
     )
-    @pytest.mark.parametrize("ordered", [True, False])
     def test_set_dtype_many(self, values, categories, new_categories, ordered):
         c = Categorical(values, categories)
         expected = Categorical(values, new_categories, ordered)
diff --git a/pandas/tests/arrays/datetimes/test_constructors.py b/pandas/tests/arrays/datetimes/test_constructors.py
index 97fa6e8d529b7..e14cc6eba5857 100644
--- a/pandas/tests/arrays/datetimes/test_constructors.py
+++ b/pandas/tests/arrays/datetimes/test_constructors.py
@@ -142,7 +142,6 @@ def test_copy(self):
         arr = DatetimeArray(data, copy=True)
         assert arr._ndarray is not data
 
-    @pytest.mark.parametrize("unit", ["s", "ms", "us", "ns"])
     def test_numpy_datetime_unit(self, unit):
         data = np.array([1, 2, 3], dtype=f"M8[{unit}]")
         arr = DatetimeArray(data)
diff --git a/pandas/tests/arrays/integer/test_dtypes.py b/pandas/tests/arrays/integer/test_dtypes.py
index e3848cdfe3aa9..99db05229a57d 100644
--- a/pandas/tests/arrays/integer/test_dtypes.py
+++ b/pandas/tests/arrays/integer/test_dtypes.py
@@ -59,7 +59,6 @@ def test_astype_nansafe():
         arr.astype("uint32")
 
 
-@pytest.mark.parametrize("dropna", [True, False])
 def test_construct_index(all_data, dropna):
     # ensure that we do not coerce to different Index dtype or non-index
 
@@ -76,7 +75,6 @@ def test_construct_index(all_data, dropna):
     tm.assert_index_equal(result, expected)
 
 
-@pytest.mark.parametrize("dropna", [True, False])
 def test_astype_index(all_data, dropna):
     # as an int/uint index to Index
 
diff --git a/pandas/tests/base/test_unique.py b/pandas/tests/base/test_unique.py
index d3fe144f70cfc..3a8ed471f9dc0 100644
--- a/pandas/tests/base/test_unique.py
+++ b/pandas/tests/base/test_unique.py
@@ -116,7 +116,6 @@ def test_unique_bad_unicode(index_or_series):
         tm.assert_numpy_array_equal(result, expected)
 
 
-@pytest.mark.parametrize("dropna", [True, False])
 def test_nunique_dropna(dropna):
     # GH37566
     ser = pd.Series(["yes", "yes", pd.NA, np.nan, None, pd.NaT])
diff --git a/pandas/tests/base/test_value_counts.py b/pandas/tests/base/test_value_counts.py
index 2729666398877..a0b0bdfdb46d8 100644
--- a/pandas/tests/base/test_value_counts.py
+++ b/pandas/tests/base/test_value_counts.py
@@ -329,7 +329,6 @@ def test_value_counts_timedelta64(index_or_series, unit):
     tm.assert_series_equal(result2, expected_s)
 
 
-@pytest.mark.parametrize("dropna", [True, False])
 def test_value_counts_with_nan(dropna, index_or_series):
     # GH31944
     klass = index_or_series
diff --git a/pandas/tests/dtypes/test_dtypes.py b/pandas/tests/dtypes/test_dtypes.py
index 0dad0b05303ad..c52d49034f74e 100644
--- a/pandas/tests/dtypes/test_dtypes.py
+++ b/pandas/tests/dtypes/test_dtypes.py
@@ -959,25 +959,24 @@ def test_same_categories_different_order(self):
         c2 = CategoricalDtype(["b", "a"], ordered=True)
         assert c1 is not c2
 
-    @pytest.mark.parametrize("ordered1", [True, False, None])
     @pytest.mark.parametrize("ordered2", [True, False, None])
-    def test_categorical_equality(self, ordered1, ordered2):
+    def test_categorical_equality(self, ordered, ordered2):
         # same categories, same order
         # any combination of None/False are equal
         # True/True is the only combination with True that are equal
-        c1 = CategoricalDtype(list("abc"), ordered1)
+        c1 = CategoricalDtype(list("abc"), ordered)
         c2 = CategoricalDtype(list("abc"), ordered2)
         result = c1 == c2
-        expected = bool(ordered1) is bool(ordered2)
+        expected = bool(ordered) is bool(ordered2)
         assert result is expected
 
         # same categories, different order
         # any combination of None/False are equal (order doesn't matter)
         # any combination with True are not equal (different order of cats)
-        c1 = CategoricalDtype(list("abc"), ordered1)
+        c1 = CategoricalDtype(list("abc"), ordered)
         c2 = CategoricalDtype(list("cab"), ordered2)
         result = c1 == c2
-        expected = (bool(ordered1) is False) and (bool(ordered2) is False)
+        expected = (bool(ordered) is False) and (bool(ordered2) is False)
         assert result is expected
 
         # different categories
@@ -985,9 +984,9 @@ def test_categorical_equality(self, ordered1, ordered2):
         assert c1 != c2
 
         # none categories
-        c1 = CategoricalDtype(list("abc"), ordered1)
+        c1 = CategoricalDtype(list("abc"), ordered)
         c2 = CategoricalDtype(None, ordered2)
-        c3 = CategoricalDtype(None, ordered1)
+        c3 = CategoricalDtype(None, ordered)
         assert c1 != c2
         assert c2 != c1
         assert c2 == c3
diff --git a/pandas/tests/extension/base/methods.py b/pandas/tests/extension/base/methods.py
index 6de5c97cbfb5e..ba247f51e5f1b 100644
--- a/pandas/tests/extension/base/methods.py
+++ b/pandas/tests/extension/base/methods.py
@@ -37,7 +37,6 @@ def test_value_counts_default_dropna(self, data):
         kwarg = sig.parameters["dropna"]
         assert kwarg.default is True
 
-    @pytest.mark.parametrize("dropna", [True, False])
     def test_value_counts(self, all_data, dropna):
         all_data = all_data[:10]
         if dropna:
diff --git a/pandas/tests/extension/base/setitem.py b/pandas/tests/extension/base/setitem.py
index ca19845041e23..c3259fe0fb4c9 100644
--- a/pandas/tests/extension/base/setitem.py
+++ b/pandas/tests/extension/base/setitem.py
@@ -105,10 +105,9 @@ def test_setitem_sequence_broadcasts(self, data, box_in_series):
         assert data[0] == data[2]
         assert data[1] == data[2]
 
-    @pytest.mark.parametrize("setter", ["loc", "iloc"])
-    def test_setitem_scalar(self, data, setter):
+    def test_setitem_scalar(self, data, indexer_li):
         arr = pd.Series(data)
-        setter = getattr(arr, setter)
+        setter = indexer_li(arr)
         setter[0] = data[1]
         assert arr[0] == data[1]
 
diff --git a/pandas/tests/extension/decimal/test_decimal.py b/pandas/tests/extension/decimal/test_decimal.py
index b3c57ee49a724..49f29b2194cae 100644
--- a/pandas/tests/extension/decimal/test_decimal.py
+++ b/pandas/tests/extension/decimal/test_decimal.py
@@ -227,8 +227,7 @@ def test_fillna_copy_series(self, data_missing, using_copy_on_write):
         with tm.assert_produces_warning(warn, match=msg, check_stacklevel=False):
             super().test_fillna_copy_series(data_missing)
 
-    @pytest.mark.parametrize("dropna", [True, False])
-    def test_value_counts(self, all_data, dropna, request):
+    def test_value_counts(self, all_data, dropna):
         all_data = all_data[:10]
         if dropna:
             other = np.array(all_data[~all_data.isna()])
diff --git a/pandas/tests/extension/test_arrow.py b/pandas/tests/extension/test_arrow.py
index 2634d40639661..d2bd0d1eca554 100644
--- a/pandas/tests/extension/test_arrow.py
+++ b/pandas/tests/extension/test_arrow.py
@@ -2300,7 +2300,6 @@ def test_str_extract_expand():
     tm.assert_series_equal(result, expected)
 
 
-@pytest.mark.parametrize("unit", ["ns", "us", "ms", "s"])
 def test_duration_from_strings_with_nat(unit):
     # GH51175
     strings = ["1000", "NaT"]
diff --git a/pandas/tests/frame/methods/test_astype.py b/pandas/tests/frame/methods/test_astype.py
index 5a1e3cd786f84..b73c759518b0e 100644
--- a/pandas/tests/frame/methods/test_astype.py
+++ b/pandas/tests/frame/methods/test_astype.py
@@ -498,11 +498,10 @@ def test_astype_to_datetime_unit(self, unit):
         assert exp_dta.dtype == dtype
         tm.assert_extension_array_equal(res_dta, exp_dta)
 
-    @pytest.mark.parametrize("unit", ["ns"])
-    def test_astype_to_timedelta_unit_ns(self, unit):
+    def test_astype_to_timedelta_unit_ns(self):
         # preserver the timedelta conversion
         # GH#19223
-        dtype = f"m8[{unit}]"
+        dtype = "m8[ns]"
         arr = np.array([[1, 2, 3]], dtype=dtype)
         df = DataFrame(arr)
         result = df.astype(dtype)
diff --git a/pandas/tests/groupby/test_apply.py b/pandas/tests/groupby/test_apply.py
index 34b6e7c4cde5f..f4b228eb5b326 100644
--- a/pandas/tests/groupby/test_apply.py
+++ b/pandas/tests/groupby/test_apply.py
@@ -1282,7 +1282,6 @@ def test_apply_by_cols_equals_apply_by_rows_transposed():
     tm.assert_frame_equal(by_cols, df)
 
 
-@pytest.mark.parametrize("dropna", [True, False])
 def test_apply_dropna_with_indexed_same(dropna):
     # GH 38227
     # GH#43205
@@ -1394,7 +1393,6 @@ def test_groupby_apply_to_series_name():
     tm.assert_series_equal(result, expected)
 
 
-@pytest.mark.parametrize("dropna", [True, False])
 def test_apply_na(dropna):
     # GH#28984
     df = DataFrame(
diff --git a/pandas/tests/groupby/test_groupby_dropna.py b/pandas/tests/groupby/test_groupby_dropna.py
index 73638eba0a3b3..ca097bc2be8bb 100644
--- a/pandas/tests/groupby/test_groupby_dropna.py
+++ b/pandas/tests/groupby/test_groupby_dropna.py
@@ -167,7 +167,6 @@ def test_groupby_dropna_series_by(dropna, expected):
     tm.assert_series_equal(result, expected)
 
 
-@pytest.mark.parametrize("dropna", (False, True))
 def test_grouper_dropna_propagation(dropna):
     # GH 36604
     df = pd.DataFrame({"A": [0, 0, 1, None], "B": [1, 2, 3, None]})
diff --git a/pandas/tests/groupby/test_missing.py b/pandas/tests/groupby/test_missing.py
index 3180a92be1236..6c029c10817d9 100644
--- a/pandas/tests/groupby/test_missing.py
+++ b/pandas/tests/groupby/test_missing.py
@@ -109,7 +109,6 @@ def test_fill_consistency():
 
 
 @pytest.mark.parametrize("method", ["ffill", "bfill"])
-@pytest.mark.parametrize("dropna", [True, False])
 @pytest.mark.parametrize("has_nan_group", [True, False])
 def test_ffill_handles_nan_groups(dropna, method, has_nan_group):
     # GH 34725
diff --git a/pandas/tests/indexes/datetimes/methods/test_snap.py b/pandas/tests/indexes/datetimes/methods/test_snap.py
index 7064e9e7993f8..651e4383a3fac 100644
--- a/pandas/tests/indexes/datetimes/methods/test_snap.py
+++ b/pandas/tests/indexes/datetimes/methods/test_snap.py
@@ -9,7 +9,6 @@
 
 @pytest.mark.parametrize("tz", [None, "Asia/Shanghai", "Europe/Berlin"])
 @pytest.mark.parametrize("name", [None, "my_dti"])
-@pytest.mark.parametrize("unit", ["ns", "us", "ms", "s"])
 def test_dti_snap(name, tz, unit):
     dti = DatetimeIndex(
         [
diff --git a/pandas/tests/indexes/test_datetimelike.py b/pandas/tests/indexes/test_datetimelike.py
index 21a686e8bc05b..330ea50dc1373 100644
--- a/pandas/tests/indexes/test_datetimelike.py
+++ b/pandas/tests/indexes/test_datetimelike.py
@@ -162,7 +162,6 @@ def test_where_cast_str(self, simple_index):
         result = index.where(mask, ["foo"])
         tm.assert_index_equal(result, expected)
 
-    @pytest.mark.parametrize("unit", ["ns", "us", "ms", "s"])
     def test_diff(self, unit):
         # GH 55080
         dti = pd.to_datetime([10, 20, 30], unit=unit).as_unit(unit)
diff --git a/pandas/tests/interchange/test_impl.py b/pandas/tests/interchange/test_impl.py
index 15c2b8d000b37..8bc6b48922a4f 100644
--- a/pandas/tests/interchange/test_impl.py
+++ b/pandas/tests/interchange/test_impl.py
@@ -304,7 +304,6 @@ def test_multi_chunk_pyarrow() -> None:
 
 
 @pytest.mark.parametrize("tz", ["UTC", "US/Pacific"])
-@pytest.mark.parametrize("unit", ["s", "ms", "us", "ns"])
 def test_datetimetzdtype(tz, unit):
     # GH 54239
     tz_data = (
diff --git a/pandas/tests/io/json/test_pandas.py b/pandas/tests/io/json/test_pandas.py
index 9d608165ede6c..ce9b601797abd 100644
--- a/pandas/tests/io/json/test_pandas.py
+++ b/pandas/tests/io/json/test_pandas.py
@@ -957,7 +957,6 @@ def test_date_format_series_raises(self, datetime_series):
         with pytest.raises(ValueError, match=msg):
             ts.to_json(date_format="iso", date_unit="foo")
 
-    @pytest.mark.parametrize("unit", ["s", "ms", "us", "ns"])
     def test_date_unit(self, unit, datetime_frame):
         df = datetime_frame
         df["date"] = Timestamp("20130101 20:43:42").as_unit("ns")
diff --git a/pandas/tests/resample/test_timedelta.py b/pandas/tests/resample/test_timedelta.py
index 7c70670d42908..309810b656ed3 100644
--- a/pandas/tests/resample/test_timedelta.py
+++ b/pandas/tests/resample/test_timedelta.py
@@ -176,7 +176,6 @@ def test_resample_with_timedelta_yields_no_empty_groups(duplicates):
     tm.assert_frame_equal(result, expected)
 
 
-@pytest.mark.parametrize("unit", ["s", "ms", "us", "ns"])
 def test_resample_quantile_timedelta(unit):
     # GH: 29485
     dtype = np.dtype(f"m8[{unit}]")
diff --git a/pandas/tests/reshape/test_pivot.py b/pandas/tests/reshape/test_pivot.py
index 5ca0da3991b8e..3cadf9c22175f 100644
--- a/pandas/tests/reshape/test_pivot.py
+++ b/pandas/tests/reshape/test_pivot.py
@@ -2318,7 +2318,6 @@ def test_pivot_table_with_margins_and_numeric_columns(self):
 
         tm.assert_frame_equal(result, expected)
 
-    @pytest.mark.parametrize("dropna", [True, False])
     def test_pivot_ea_dtype_dropna(self, dropna):
         # GH#47477
         df = DataFrame({"x": "a", "y": "b", "age": Series([20, 40], dtype="Int64")})
diff --git a/pandas/tests/scalar/timedelta/methods/test_round.py b/pandas/tests/scalar/timedelta/methods/test_round.py
index 4beb39510413c..a8ca7f741d966 100644
--- a/pandas/tests/scalar/timedelta/methods/test_round.py
+++ b/pandas/tests/scalar/timedelta/methods/test_round.py
@@ -168,7 +168,6 @@ def checker(ts, nanos, unit):
         nanos = 24 * 60 * 60 * 1_000_000_000
         checker(td, nanos, "D")
 
-    @pytest.mark.parametrize("unit", ["ns", "us", "ms", "s"])
     def test_round_non_nano(self, unit):
         td = Timedelta("1 days 02:34:57").as_unit(unit)
 
diff --git a/pandas/tests/scalar/timestamp/methods/test_normalize.py b/pandas/tests/scalar/timestamp/methods/test_normalize.py
index e097c9673e17a..60f249c602bd6 100644
--- a/pandas/tests/scalar/timestamp/methods/test_normalize.py
+++ b/pandas/tests/scalar/timestamp/methods/test_normalize.py
@@ -6,7 +6,6 @@
 
 class TestTimestampNormalize:
     @pytest.mark.parametrize("arg", ["2013-11-30", "2013-11-30 12:00:00"])
-    @pytest.mark.parametrize("unit", ["ns", "us", "ms", "s"])
     def test_normalize(self, tz_naive_fixture, arg, unit):
         tz = tz_naive_fixture
         ts = Timestamp(arg, tz=tz).as_unit(unit)
diff --git a/pandas/tests/scalar/timestamp/methods/test_replace.py b/pandas/tests/scalar/timestamp/methods/test_replace.py
index 8a208455edc82..d67de79a8dd10 100644
--- a/pandas/tests/scalar/timestamp/methods/test_replace.py
+++ b/pandas/tests/scalar/timestamp/methods/test_replace.py
@@ -157,7 +157,6 @@ def test_replace_across_dst(self, tz, normalize):
         ts2b = normalize(ts2)
         assert ts2 == ts2b
 
-    @pytest.mark.parametrize("unit", ["ns", "us", "ms", "s"])
     def test_replace_dst_border(self, unit):
         # Gh 7825
         t = Timestamp("2013-11-3", tz="America/Chicago").as_unit(unit)
@@ -168,7 +167,6 @@ def test_replace_dst_border(self, unit):
 
     @pytest.mark.parametrize("fold", [0, 1])
     @pytest.mark.parametrize("tz", ["dateutil/Europe/London", "Europe/London"])
-    @pytest.mark.parametrize("unit", ["ns", "us", "ms", "s"])
     def test_replace_dst_fold(self, fold, tz, unit):
         # GH 25017
         d = datetime(2019, 10, 27, 2, 30)
diff --git a/pandas/tests/scalar/timestamp/methods/test_round.py b/pandas/tests/scalar/timestamp/methods/test_round.py
index d10ee18b47f19..59c0fe8bbebfb 100644
--- a/pandas/tests/scalar/timestamp/methods/test_round.py
+++ b/pandas/tests/scalar/timestamp/methods/test_round.py
@@ -147,7 +147,6 @@ def test_round_minute_freq(self, test_input, freq, expected, rounder):
         result = func(freq)
         assert result == expected
 
-    @pytest.mark.parametrize("unit", ["ns", "us", "ms", "s"])
     def test_ceil(self, unit):
         dt = Timestamp("20130101 09:10:11").as_unit(unit)
         result = dt.ceil("D")
@@ -155,7 +154,6 @@ def test_ceil(self, unit):
         assert result == expected
         assert result._creso == dt._creso
 
-    @pytest.mark.parametrize("unit", ["ns", "us", "ms", "s"])
     def test_floor(self, unit):
         dt = Timestamp("20130101 09:10:11").as_unit(unit)
         result = dt.floor("D")
diff --git a/pandas/tests/scalar/timestamp/methods/test_tz_localize.py b/pandas/tests/scalar/timestamp/methods/test_tz_localize.py
index 9df0a023730de..cf221822fe8bf 100644
--- a/pandas/tests/scalar/timestamp/methods/test_tz_localize.py
+++ b/pandas/tests/scalar/timestamp/methods/test_tz_localize.py
@@ -49,7 +49,6 @@ def test_tz_localize_pushes_out_of_bounds(self):
         with pytest.raises(OutOfBoundsDatetime, match=msg):
             Timestamp.max.tz_localize("US/Pacific")
 
-    @pytest.mark.parametrize("unit", ["ns", "us", "ms", "s"])
     def test_tz_localize_ambiguous_bool(self, unit):
         # make sure that we are correctly accepting bool values as ambiguous
         # GH#14402
@@ -294,7 +293,6 @@ def test_timestamp_tz_localize(self, tz):
         ],
     )
     @pytest.mark.parametrize("tz_type", ["", "dateutil/"])
-    @pytest.mark.parametrize("unit", ["ns", "us", "ms", "s"])
     def test_timestamp_tz_localize_nonexistent_shift(
         self, start_ts, tz, end_ts, shift, tz_type, unit
     ):
@@ -326,7 +324,6 @@ def test_timestamp_tz_localize_nonexistent_shift_invalid(self, offset, warsaw):
         with pytest.raises(ValueError, match=msg):
             ts.tz_localize(tz, nonexistent=timedelta(seconds=offset))
 
-    @pytest.mark.parametrize("unit", ["ns", "us", "ms", "s"])
     def test_timestamp_tz_localize_nonexistent_NaT(self, warsaw, unit):
         # GH 8917
         tz = warsaw
@@ -334,7 +331,6 @@ def test_timestamp_tz_localize_nonexistent_NaT(self, warsaw, unit):
         result = ts.tz_localize(tz, nonexistent="NaT")
         assert result is NaT
 
-    @pytest.mark.parametrize("unit", ["ns", "us", "ms", "s"])
     def test_timestamp_tz_localize_nonexistent_raise(self, warsaw, unit):
         # GH 8917
         tz = warsaw
diff --git a/pandas/tests/tseries/frequencies/test_inference.py b/pandas/tests/tseries/frequencies/test_inference.py
index 45741e852fef7..e96af6c6faf35 100644
--- a/pandas/tests/tseries/frequencies/test_inference.py
+++ b/pandas/tests/tseries/frequencies/test_inference.py
@@ -229,7 +229,6 @@ def test_infer_freq_index(freq, expected):
         }.items()
     ),
 )
-@pytest.mark.parametrize("unit", ["s", "ms", "us", "ns"])
 def test_infer_freq_tz(tz_naive_fixture, expected, dates, unit):
     # see gh-7310, GH#55609
     tz = tz_naive_fixture
diff --git a/pandas/tests/tseries/offsets/test_business_hour.py b/pandas/tests/tseries/offsets/test_business_hour.py
index 2779100f5355c..e675977c6fab4 100644
--- a/pandas/tests/tseries/offsets/test_business_hour.py
+++ b/pandas/tests/tseries/offsets/test_business_hour.py
@@ -947,7 +947,6 @@ def test_apply_nanoseconds(self):
                 assert_offset_equal(offset, base, expected)
 
     @pytest.mark.parametrize("td_unit", ["s", "ms", "us", "ns"])
-    @pytest.mark.parametrize("unit", ["s", "ms", "us", "ns"])
     def test_bday_ignores_timedeltas(self, unit, td_unit):
         # GH#55608
         idx = date_range("2010/02/01", "2010/02/10", freq="12h", unit=unit)
diff --git a/pandas/tests/window/test_rolling.py b/pandas/tests/window/test_rolling.py
index 19c24f1c5b189..7ab6e7863ad81 100644
--- a/pandas/tests/window/test_rolling.py
+++ b/pandas/tests/window/test_rolling.py
@@ -1945,7 +1945,6 @@ def test_numeric_only_corr_cov_series(kernel, use_arg, numeric_only, dtype):
         tm.assert_series_equal(result, expected)
 
 
-@pytest.mark.parametrize("unit", ["s", "ms", "us", "ns"])
 @pytest.mark.parametrize("tz", [None, "UTC", "Europe/Prague"])
 def test_rolling_timedelta_window_non_nanoseconds(unit, tz):
     # Test Sum, GH#55106

From 9289d87fb360483879aebfac126d6ef9e06dfde1 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Wed, 20 Dec 2023 17:39:10 -0800
Subject: [PATCH 26/26] Fix errors

---
 pandas/tests/apply/test_str.py             | 1 +
 pandas/tests/arrays/test_datetimes.py      | 5 +++++
 pandas/tests/extension/test_categorical.py | 4 ----
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/pandas/tests/apply/test_str.py b/pandas/tests/apply/test_str.py
index 4b3c86378734a..e9967b75becce 100644
--- a/pandas/tests/apply/test_str.py
+++ b/pandas/tests/apply/test_str.py
@@ -49,6 +49,7 @@ def test_with_string_args(datetime_series, all_numeric_reductions):
     assert result == expected
 
 
+@pytest.mark.parametrize("op", ["mean", "median", "std", "var"])
 @pytest.mark.parametrize("how", ["agg", "apply"])
 def test_apply_np_reducer(op, how):
     # GH 39116
diff --git a/pandas/tests/arrays/test_datetimes.py b/pandas/tests/arrays/test_datetimes.py
index 675d500ca4401..db86f62a10484 100644
--- a/pandas/tests/arrays/test_datetimes.py
+++ b/pandas/tests/arrays/test_datetimes.py
@@ -28,6 +28,11 @@
 
 
 class TestNonNano:
+    @pytest.fixture(params=["s", "ms", "us"])
+    def unit(self, request):
+        """Fixture returning parametrized time units"""
+        return request.param
+
     @pytest.fixture
     def dtype(self, unit, tz_naive_fixture):
         tz = tz_naive_fixture
diff --git a/pandas/tests/extension/test_categorical.py b/pandas/tests/extension/test_categorical.py
index 7598aca10bad4..a8731da2e70f7 100644
--- a/pandas/tests/extension/test_categorical.py
+++ b/pandas/tests/extension/test_categorical.py
@@ -122,10 +122,6 @@ def test_getitem_scalar(self, data):
         # to break things by changing.
         super().test_getitem_scalar(data)
 
-    @pytest.mark.xfail(reason="Unobserved categories included")
-    def test_value_counts(self, all_data, dropna):
-        return super().test_value_counts(all_data, dropna)
-
     def test_combine_add(self, data_repeated):
         # GH 20825
         # When adding categoricals in combine, result is a string