From 969e0a24d160dd64c89160ded2506f3551a72a25 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Tue, 29 Jul 2025 10:59:48 -0700
Subject: [PATCH 1/6] Error on pytest.PytestWarning

---
 pandas/tests/arrays/test_datetimes.py            | 2 +-
 pandas/tests/dtypes/test_dtypes.py               | 8 ++++++--
 pandas/tests/frame/test_ufunc.py                 | 2 +-
 pandas/tests/indexes/numeric/test_indexing.py    | 4 ++--
 pandas/tests/indexes/test_base.py                | 4 ++--
 pandas/tests/indexing/multiindex/test_getitem.py | 8 ++++++--
 pandas/tests/io/json/test_normalize.py           | 2 +-
 pandas/tests/io/parser/common/test_chunksize.py  | 2 +-
 pandas/tests/series/test_ufunc.py                | 2 +-
 pyproject.toml                                   | 1 +
 10 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/pandas/tests/arrays/test_datetimes.py b/pandas/tests/arrays/test_datetimes.py
index 87505b1b22fc4..944bd84145f05 100644
--- a/pandas/tests/arrays/test_datetimes.py
+++ b/pandas/tests/arrays/test_datetimes.py
@@ -100,7 +100,7 @@ def test_simple_new_requires_match(self, unit):
         assert dta.dtype == dtype
 
         wrong = DatetimeTZDtype("ns", "UTC")
-        with pytest.raises(AssertionError, match=""):
+        with pytest.raises(AssertionError, match="^$"):
             DatetimeArray._simple_new(arr, dtype=wrong)
 
     def test_std_non_nano(self, unit):
diff --git a/pandas/tests/dtypes/test_dtypes.py b/pandas/tests/dtypes/test_dtypes.py
index 621217a8c9317..c9d3f83ce9237 100644
--- a/pandas/tests/dtypes/test_dtypes.py
+++ b/pandas/tests/dtypes/test_dtypes.py
@@ -249,10 +249,14 @@ def test_alias_to_unit_raises(self):
 
     def test_alias_to_unit_bad_alias_raises(self):
         # 23990
-        with pytest.raises(TypeError, match=""):
+        with pytest.raises(
+            TypeError, match="Cannot construct a 'DatetimeTZDtype' from"
+        ):
             DatetimeTZDtype("this is a bad string")
 
-        with pytest.raises(TypeError, match=""):
+        with pytest.raises(
+            TypeError, match="Cannot construct a 'DatetimeTZDtype' from"
+        ):
             DatetimeTZDtype("datetime64[ns, US/NotATZ]")
 
     def test_hash_vs_equality(self, dtype):
diff --git a/pandas/tests/frame/test_ufunc.py b/pandas/tests/frame/test_ufunc.py
index 092e65dd4b431..ce66d448a0d40 100644
--- a/pandas/tests/frame/test_ufunc.py
+++ b/pandas/tests/frame/test_ufunc.py
@@ -191,7 +191,7 @@ def test_unary_accumulate_axis():
 
 def test_frame_outer_disallowed():
     df = pd.DataFrame({"A": [1, 2]})
-    with pytest.raises(NotImplementedError, match=""):
+    with pytest.raises(NotImplementedError, match="^$"):
         # deprecation enforced in 2.0
         np.subtract.outer(df, df)
 
diff --git a/pandas/tests/indexes/numeric/test_indexing.py b/pandas/tests/indexes/numeric/test_indexing.py
index 3c1b98d57b2a0..b29f783203177 100644
--- a/pandas/tests/indexes/numeric/test_indexing.py
+++ b/pandas/tests/indexes/numeric/test_indexing.py
@@ -585,10 +585,10 @@ def test_slice_locs_na(self):
 
     def test_slice_locs_na_raises(self):
         index = Index([np.nan, 1, 2])
-        with pytest.raises(KeyError, match=""):
+        with pytest.raises(KeyError, match="1.5"):
             index.slice_locs(start=1.5)
 
-        with pytest.raises(KeyError, match=""):
+        with pytest.raises(KeyError, match="1.5"):
             index.slice_locs(end=1.5)
 
 
diff --git a/pandas/tests/indexes/test_base.py b/pandas/tests/indexes/test_base.py
index e734878e6a102..985ed880e7998 100644
--- a/pandas/tests/indexes/test_base.py
+++ b/pandas/tests/indexes/test_base.py
@@ -712,7 +712,7 @@ def test_drop_by_str_label(self, index):
     )
     @pytest.mark.parametrize("keys", [["foo", "bar"], ["1", "bar"]])
     def test_drop_by_str_label_raises_missing_keys(self, index, keys):
-        with pytest.raises(KeyError, match=""):
+        with pytest.raises(KeyError, match=".* not found in axis"):
             index.drop(keys)
 
     @pytest.mark.parametrize(
@@ -741,7 +741,7 @@ def test_drop_by_numeric_label_loc(self):
 
     def test_drop_by_numeric_label_raises_missing_keys(self):
         index = Index([1, 2, 3])
-        with pytest.raises(KeyError, match=""):
+        with pytest.raises(KeyError, match=re.escape("[4] not found in axis")):
             index.drop([3, 4])
 
     @pytest.mark.parametrize(
diff --git a/pandas/tests/indexing/multiindex/test_getitem.py b/pandas/tests/indexing/multiindex/test_getitem.py
index b86e233110e88..41e90fca281e1 100644
--- a/pandas/tests/indexing/multiindex/test_getitem.py
+++ b/pandas/tests/indexing/multiindex/test_getitem.py
@@ -89,8 +89,12 @@ def test_series_getitem_returns_scalar(
         (lambda s: s[(2000, 3, 4)], KeyError, r"^\(2000, 3, 4\)$"),
         (lambda s: s.loc[(2000, 3, 4)], KeyError, r"^\(2000, 3, 4\)$"),
         (lambda s: s.loc[(2000, 3, 4, 5)], IndexingError, "Too many indexers"),
-        (lambda s: s.__getitem__(len(s)), KeyError, ""),  # match should include len(s)
-        (lambda s: s[len(s)], KeyError, ""),  # match should include len(s)
+        (
+            lambda s: s.__getitem__(len(s)),
+            KeyError,
+            "100",
+        ),  # match should include len(s)
+        (lambda s: s[len(s)], KeyError, "100"),  # match should include len(s)
         (
             lambda s: s.iloc[len(s)],
             IndexError,
diff --git a/pandas/tests/io/json/test_normalize.py b/pandas/tests/io/json/test_normalize.py
index fdbfbd004617e..cde0a7a378cff 100644
--- a/pandas/tests/io/json/test_normalize.py
+++ b/pandas/tests/io/json/test_normalize.py
@@ -172,7 +172,7 @@ def test_empty_array(self):
     )
     def test_accepted_input(self, data, record_path, exception_type):
         if exception_type is not None:
-            with pytest.raises(exception_type, match=""):
+            with pytest.raises(exception_type, match="^$"):
                 json_normalize(data, record_path=record_path)
         else:
             result = json_normalize(data, record_path=record_path)
diff --git a/pandas/tests/io/parser/common/test_chunksize.py b/pandas/tests/io/parser/common/test_chunksize.py
index 65ad7273666e5..75ec96409bdd0 100644
--- a/pandas/tests/io/parser/common/test_chunksize.py
+++ b/pandas/tests/io/parser/common/test_chunksize.py
@@ -129,7 +129,7 @@ def test_read_chunksize_and_nrows_changing_size(all_parsers):
         tm.assert_frame_equal(reader.get_chunk(size=2), expected.iloc[:2])
         tm.assert_frame_equal(reader.get_chunk(size=4), expected.iloc[2:5])
 
-        with pytest.raises(StopIteration, match=""):
+        with pytest.raises(StopIteration, match="^$"):
             reader.get_chunk(size=3)
 
 
diff --git a/pandas/tests/series/test_ufunc.py b/pandas/tests/series/test_ufunc.py
index a5976bb2518c9..5faacbb5559a9 100644
--- a/pandas/tests/series/test_ufunc.py
+++ b/pandas/tests/series/test_ufunc.py
@@ -414,7 +414,7 @@ def test_outer():
     ser = pd.Series([1, 2, 3])
     obj = np.array([1, 2, 3])
 
-    with pytest.raises(NotImplementedError, match=""):
+    with pytest.raises(NotImplementedError, match="^$"):
         np.subtract.outer(ser, obj)
 
 
diff --git a/pyproject.toml b/pyproject.toml
index 0dd5c65413936..228ba5fdc6a55 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -457,6 +457,7 @@ filterwarnings = [
   "error:::pandas",
   "error::ResourceWarning",
   "error::pytest.PytestUnraisableExceptionWarning",
+  "error::pytest.PytestWarning",
   # TODO(PY311-minimum): Specify EncodingWarning
   # Ignore 3rd party EncodingWarning but raise on pandas'
   "ignore:.*encoding.* argument not specified",

From 93d804ae4a2e44722b55de600bb526f9a16b6a06 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Tue, 29 Jul 2025 11:07:36 -0700
Subject: [PATCH 2/6] ignore runtimewarning in plotting tests

---
 pandas/tests/io/test_sql.py               | 2 +-
 pandas/tests/plotting/frame/test_frame.py | 4 ++++
 pandas/tests/plotting/test_series.py      | 4 ++++
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/pandas/tests/io/test_sql.py b/pandas/tests/io/test_sql.py
index 6f4c1602a5e64..f8638ea104933 100644
--- a/pandas/tests/io/test_sql.py
+++ b/pandas/tests/io/test_sql.py
@@ -2226,7 +2226,7 @@ def test_api_chunksize_read(conn, request):
 
     # reading the query in chunks with read_sql_query
     if conn_name == "sqlite_buildin":
-        with pytest.raises(NotImplementedError, match=""):
+        with pytest.raises(NotImplementedError, match="^$"):
             sql.read_sql_table("test_chunksize", conn, chunksize=5)
     else:
         res3 = DataFrame()
diff --git a/pandas/tests/plotting/frame/test_frame.py b/pandas/tests/plotting/frame/test_frame.py
index 3f274a336ad44..f944609471a42 100644
--- a/pandas/tests/plotting/frame/test_frame.py
+++ b/pandas/tests/plotting/frame/test_frame.py
@@ -52,6 +52,10 @@
 mpl = pytest.importorskip("matplotlib")
 plt = pytest.importorskip("matplotlib.pyplot")
 
+pytestmark = pytest.mark.filterwarnings(
+    "ignore:divide by zero encountered in scalar divide:RuntimeWarning"
+)
+
 
 class TestDataFramePlots:
     @pytest.mark.slow
diff --git a/pandas/tests/plotting/test_series.py b/pandas/tests/plotting/test_series.py
index eb1b4f7d85a68..757b380559627 100644
--- a/pandas/tests/plotting/test_series.py
+++ b/pandas/tests/plotting/test_series.py
@@ -40,6 +40,10 @@
 from pandas.plotting._matplotlib.converter import DatetimeConverter
 from pandas.plotting._matplotlib.style import get_standard_colors
 
+pytestmark = pytest.mark.filterwarnings(
+    "ignore:divide by zero encountered in scalar divide:RuntimeWarning"
+)
+
 
 @pytest.fixture
 def ts():

From 769d02faf1deb8a724e63c3bb64a24616b04871a Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Tue, 29 Jul 2025 11:17:24 -0700
Subject: [PATCH 3/6] Ignore PytestAssertRewriteWarning for hypothesis

---
 pyproject.toml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pyproject.toml b/pyproject.toml
index 228ba5fdc6a55..2fb519e590d38 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -458,6 +458,8 @@ filterwarnings = [
   "error::ResourceWarning",
   "error::pytest.PytestUnraisableExceptionWarning",
   "error::pytest.PytestWarning",
+  # e.g. Module already imported so cannot be rewritten; _hypothesis_globals
+  "ignore::pytest.PytestAssertRewriteWarning",
   # TODO(PY311-minimum): Specify EncodingWarning
   # Ignore 3rd party EncodingWarning but raise on pandas'
   "ignore:.*encoding.* argument not specified",

From 91e6c86a24c794653ac65bd4dc85de8cbcf28672 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Tue, 29 Jul 2025 11:25:47 -0700
Subject: [PATCH 4/6] Clarify past no future infer strings

---
 .github/workflows/unit-tests.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index 412f27cba9c4f..7bee8474d4db5 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -71,7 +71,7 @@ jobs:
             # It will be temporarily activated during tests with locale.setlocale
             extra_loc: "zh_CN"
             platform: ubuntu-24.04
-          - name: "Past no infer strings"
+          - name: "PANDAS_FUTURE_INFER_STRING=0"
             env_file: actions-312.yaml
             pandas_future_infer_string: "0"
             platform: ubuntu-24.04

From e42d2b03f9643bd846ecfcc58844f4e9918d3127 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Tue, 29 Jul 2025 11:59:29 -0700
Subject: [PATCH 5/6] Add pytest.PytestCacheWarning

---
 pyproject.toml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pyproject.toml b/pyproject.toml
index 2fb519e590d38..5c836951961f2 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -460,6 +460,7 @@ filterwarnings = [
   "error::pytest.PytestWarning",
   # e.g. Module already imported so cannot be rewritten; _hypothesis_globals
   "ignore::pytest.PytestAssertRewriteWarning",
+  "ignore::pytest.PytestCacheWarning",
   # TODO(PY311-minimum): Specify EncodingWarning
   # Ignore 3rd party EncodingWarning but raise on pandas'
   "ignore:.*encoding.* argument not specified",

From 894162959b2ad8a76021eed5e4ec0b7dd1d29f23 Mon Sep 17 00:00:00 2001
From: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
Date: Tue, 29 Jul 2025 13:58:58 -0700
Subject: [PATCH 6/6] Ignore another runtimewarning

---
 pandas/tests/plotting/frame/test_frame.py | 11 ++++++++---
 pandas/tests/plotting/test_series.py      | 11 ++++++++---
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/pandas/tests/plotting/frame/test_frame.py b/pandas/tests/plotting/frame/test_frame.py
index f944609471a42..c4ab708f33978 100644
--- a/pandas/tests/plotting/frame/test_frame.py
+++ b/pandas/tests/plotting/frame/test_frame.py
@@ -52,9 +52,14 @@
 mpl = pytest.importorskip("matplotlib")
 plt = pytest.importorskip("matplotlib.pyplot")
 
-pytestmark = pytest.mark.filterwarnings(
-    "ignore:divide by zero encountered in scalar divide:RuntimeWarning"
-)
+pytestmark = [
+    pytest.mark.filterwarnings(
+        "ignore:divide by zero encountered in scalar divide:RuntimeWarning"
+    ),
+    pytest.mark.filterwarnings(
+        "ignore:invalid value encountered in scalar multiply:RuntimeWarning"
+    ),
+]
 
 
 class TestDataFramePlots:
diff --git a/pandas/tests/plotting/test_series.py b/pandas/tests/plotting/test_series.py
index 757b380559627..779e539b3afba 100644
--- a/pandas/tests/plotting/test_series.py
+++ b/pandas/tests/plotting/test_series.py
@@ -40,9 +40,14 @@
 from pandas.plotting._matplotlib.converter import DatetimeConverter
 from pandas.plotting._matplotlib.style import get_standard_colors
 
-pytestmark = pytest.mark.filterwarnings(
-    "ignore:divide by zero encountered in scalar divide:RuntimeWarning"
-)
+pytestmark = [
+    pytest.mark.filterwarnings(
+        "ignore:divide by zero encountered in scalar divide:RuntimeWarning"
+    ),
+    pytest.mark.filterwarnings(
+        "ignore:invalid value encountered in scalar multiply:RuntimeWarning"
+    ),
+]
 
 
 @pytest.fixture