From 5fbeaebb8a34567498cb750c93c8341930a7c5d1 Mon Sep 17 00:00:00 2001
From: Fangchen Li <fangchen.li@outlook.com>
Date: Mon, 20 Jun 2022 22:55:42 -0700
Subject: [PATCH 01/26] CI: start testing Python 3.11

---
 .github/workflows/python-dev.yml | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/.github/workflows/python-dev.yml b/.github/workflows/python-dev.yml
index 09639acafbba1..d58a844f36908 100644
--- a/.github/workflows/python-dev.yml
+++ b/.github/workflows/python-dev.yml
@@ -1,11 +1,3 @@
-# This file is purposely frozen(does not run). DO NOT DELETE IT
-# Unfreeze(by commentingthe if: false() condition) once the
-# next Python Dev version has released beta 1 and both Cython and numpy support it
-# After that Python has released, migrate the workflows to the
-# posix GHA workflows and "freeze" this file by
-# uncommenting the if: false() condition
-# Feel free to modify this comment as necessary.
-
 name: Python Dev
 
 on:
@@ -29,7 +21,6 @@ env:
 
 jobs:
   build:
-    if: false # Comment this line out to "unfreeze"
     runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
@@ -50,7 +41,7 @@ jobs:
         fetch-depth: 0
 
     - name: Set up Python Dev Version
-      uses: actions/setup-python@v3
+      uses: actions/setup-python@v4
       with:
         python-version: '3.11-dev'
 
@@ -58,9 +49,10 @@ jobs:
       shell: bash -el {0}
       run: |
         python3 -m pip install --upgrade pip setuptools wheel
+        python3 -m pip install git+https://github.com/cython/cython.git
         python3 -m pip install -i https://pypi.anaconda.org/scipy-wheels-nightly/simple numpy
         python3 -m pip install git+https://github.com/nedbat/coveragepy.git
-        python3 -m pip install cython python-dateutil pytz hypothesis pytest>=6.2.5 pytest-xdist pytest-cov pytest-asyncio>=0.17
+        python3 -m pip install python-dateutil pytz hypothesis pytest>=6.2.5 pytest-xdist pytest-cov pytest-asyncio>=0.17
         python3 -m pip list
 
     - name: Build Pandas

From 4805a6b8dd7c5ed969a9f21f13edb1a1919f2c49 Mon Sep 17 00:00:00 2001
From: Fangchen Li <fangchen.li@outlook.com>
Date: Mon, 20 Jun 2022 23:06:23 -0700
Subject: [PATCH 02/26] fix

---
 .github/workflows/python-dev.yml | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/.github/workflows/python-dev.yml b/.github/workflows/python-dev.yml
index d58a844f36908..a1ed7a1156eb3 100644
--- a/.github/workflows/python-dev.yml
+++ b/.github/workflows/python-dev.yml
@@ -48,21 +48,22 @@ jobs:
     - name: Install dependencies
       shell: bash -el {0}
       run: |
-        python3 -m pip install --upgrade pip setuptools wheel
-        python3 -m pip install git+https://github.com/cython/cython.git
-        python3 -m pip install -i https://pypi.anaconda.org/scipy-wheels-nightly/simple numpy
-        python3 -m pip install git+https://github.com/nedbat/coveragepy.git
-        python3 -m pip install python-dateutil pytz hypothesis pytest>=6.2.5 pytest-xdist pytest-cov pytest-asyncio>=0.17
-        python3 -m pip list
+        python --version
+        python -m pip install --upgrade pip setuptools wheel
+        python -m pip install git+https://github.com/cython/cython.git
+        python -m pip install -i https://pypi.anaconda.org/scipy-wheels-nightly/simple numpy
+        python -m pip install git+https://github.com/nedbat/coveragepy.git
+        python -m pip install python-dateutil pytz hypothesis pytest>=6.2.5 pytest-xdist pytest-cov pytest-asyncio>=0.17
+        python -m pip list
 
     - name: Build Pandas
       run: |
-        python3 setup.py build_ext -q -j2
-        python3 -m pip install -e . --no-build-isolation --no-use-pep517
+        python setup.py build_ext -q -j2
+        python -m pip install -e . --no-build-isolation --no-use-pep517
 
     - name: Build Version
       run: |
-        python3 -c "import pandas; pandas.show_versions();"
+        python -c "import pandas; pandas.show_versions();"
 
     - name: Test
       uses: ./.github/actions/run-tests

From 9f038f3ad0f184d5f088e299ad32cc9a1f7ccf61 Mon Sep 17 00:00:00 2001
From: Fangchen Li <fangchen.li@outlook.com>
Date: Mon, 20 Jun 2022 23:38:04 -0700
Subject: [PATCH 03/26] fix

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

diff --git a/.github/workflows/python-dev.yml b/.github/workflows/python-dev.yml
index a1ed7a1156eb3..b39d9ab6b7875 100644
--- a/.github/workflows/python-dev.yml
+++ b/.github/workflows/python-dev.yml
@@ -51,7 +51,7 @@ jobs:
         python --version
         python -m pip install --upgrade pip setuptools wheel
         python -m pip install git+https://github.com/cython/cython.git
-        python -m pip install -i https://pypi.anaconda.org/scipy-wheels-nightly/simple numpy
+        python -m pip install git+https://github.com/numpy/numpy.git
         python -m pip install git+https://github.com/nedbat/coveragepy.git
         python -m pip install python-dateutil pytz hypothesis pytest>=6.2.5 pytest-xdist pytest-cov pytest-asyncio>=0.17
         python -m pip list

From 2b45e3280e43017de2a712ce11f3b1156da2f904 Mon Sep 17 00:00:00 2001
From: Fangchen Li <fangchen.li@outlook.com>
Date: Wed, 22 Jun 2022 10:52:12 -0700
Subject: [PATCH 04/26] fix macos

---
 .github/workflows/python-dev.yml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/.github/workflows/python-dev.yml b/.github/workflows/python-dev.yml
index b39d9ab6b7875..d2a8dd7e115de 100644
--- a/.github/workflows/python-dev.yml
+++ b/.github/workflows/python-dev.yml
@@ -46,7 +46,6 @@ jobs:
         python-version: '3.11-dev'
 
     - name: Install dependencies
-      shell: bash -el {0}
       run: |
         python --version
         python -m pip install --upgrade pip setuptools wheel

From bfbd17bc19dba30574cf6ff60c73d15beaaf105e Mon Sep 17 00:00:00 2001
From: Fangchen Li <fangchen.li@outlook.com>
Date: Wed, 22 Jun 2022 14:03:41 -0700
Subject: [PATCH 05/26] add error msg compat

---
 pandas/compat/__init__.py                     |  1 +
 pandas/tests/arrays/categorical/test_api.py   | 15 +++++++++++++--
 pandas/tests/indexes/multi/test_get_set.py    | 14 +++++++++++++-
 pandas/tests/indexes/period/test_freq_attr.py |  9 ++++++++-
 4 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/pandas/compat/__init__.py b/pandas/compat/__init__.py
index bb4787f07b2f0..5d3a36a902c05 100644
--- a/pandas/compat/__init__.py
+++ b/pandas/compat/__init__.py
@@ -28,6 +28,7 @@
 
 PY39 = sys.version_info >= (3, 9)
 PY310 = sys.version_info >= (3, 10)
+PY311 = sys.version_info >= (3, 11)
 PYPY = platform.python_implementation() == "PyPy"
 IS64 = sys.maxsize > 2**32
 
diff --git a/pandas/tests/arrays/categorical/test_api.py b/pandas/tests/arrays/categorical/test_api.py
index 87b1bb88aeac3..d6ff25a960857 100644
--- a/pandas/tests/arrays/categorical/test_api.py
+++ b/pandas/tests/arrays/categorical/test_api.py
@@ -3,6 +3,8 @@
 import numpy as np
 import pytest
 
+from pandas.compat import PY311
+
 from pandas import (
     Categorical,
     CategoricalIndex,
@@ -53,7 +55,11 @@ def test_set_ordered(self):
         assert not cat2.ordered
 
         # removed in 0.19.0
-        msg = "can't set attribute"
+        msg = (
+            "property 'ordered' of 'Categorical' object has no setter"
+            if PY311
+            else "can't set attribute"
+        )
         with pytest.raises(AttributeError, match=msg):
             cat.ordered = True
         with pytest.raises(AttributeError, match=msg):
@@ -507,7 +513,12 @@ def test_codes_immutable(self):
         tm.assert_numpy_array_equal(c.codes, exp)
 
         # Assignments to codes should raise
-        with pytest.raises(AttributeError, match="can't set attribute"):
+        msg = (
+            "property 'codes' of 'Categorical' object has no setter"
+            if PY311
+            else "can't set attribute"
+        )
+        with pytest.raises(AttributeError, match=msg):
             c.codes = np.array([0, 1, 2, 0, 1], dtype="int8")
 
         # changes in the codes array should raise
diff --git a/pandas/tests/indexes/multi/test_get_set.py b/pandas/tests/indexes/multi/test_get_set.py
index aa0e91cecd4fc..b22eb1f75cf6a 100644
--- a/pandas/tests/indexes/multi/test_get_set.py
+++ b/pandas/tests/indexes/multi/test_get_set.py
@@ -1,6 +1,8 @@
 import numpy as np
 import pytest
 
+from pandas.compat import PY311
+
 from pandas.core.dtypes.dtypes import DatetimeTZDtype
 
 import pandas as pd
@@ -139,9 +141,19 @@ def test_set_levels_codes_directly(idx):
     minor_codes = [(x + 1) % 1 for x in minor_codes]
     new_codes = [major_codes, minor_codes]
 
-    msg = "[Cc]an't set attribute"
+    msg = (
+        "property 'levels' of 'MultiIndex' object has no setter"
+        if PY311
+        else "can't set attribute"
+    )
     with pytest.raises(AttributeError, match=msg):
         idx.levels = new_levels
+
+    msg = (
+        "property 'codes' of 'MultiIndex' object has no setter"
+        if PY311
+        else "can't set attribute"
+    )
     with pytest.raises(AttributeError, match=msg):
         idx.codes = new_codes
 
diff --git a/pandas/tests/indexes/period/test_freq_attr.py b/pandas/tests/indexes/period/test_freq_attr.py
index 3bf3e700e5e72..e1ecffa4982bd 100644
--- a/pandas/tests/indexes/period/test_freq_attr.py
+++ b/pandas/tests/indexes/period/test_freq_attr.py
@@ -1,5 +1,7 @@
 import pytest
 
+from pandas.compat import PY311
+
 from pandas import (
     offsets,
     period_range,
@@ -17,5 +19,10 @@ def test_freq_setter_deprecated(self):
             idx.freq
 
         # warning for setter
-        with pytest.raises(AttributeError, match="can't set attribute"):
+        msg = (
+            "property 'freq' of 'PeriodArray' object has no setter"
+            if PY311
+            else "can't set attribute"
+        )
+        with pytest.raises(AttributeError, match=msg):
             idx.freq = offsets.Day()

From bac8cbdda4396f4a4672b2386d63d9c3df534b1b Mon Sep 17 00:00:00 2001
From: Fangchen Li <fangchen.li@outlook.com>
Date: Thu, 23 Jun 2022 10:08:06 -0700
Subject: [PATCH 06/26] fix error msg in test

---
 pandas/tests/indexes/multi/test_get_set.py | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/pandas/tests/indexes/multi/test_get_set.py b/pandas/tests/indexes/multi/test_get_set.py
index b22eb1f75cf6a..42cf0168f6599 100644
--- a/pandas/tests/indexes/multi/test_get_set.py
+++ b/pandas/tests/indexes/multi/test_get_set.py
@@ -141,11 +141,7 @@ def test_set_levels_codes_directly(idx):
     minor_codes = [(x + 1) % 1 for x in minor_codes]
     new_codes = [major_codes, minor_codes]
 
-    msg = (
-        "property 'levels' of 'MultiIndex' object has no setter"
-        if PY311
-        else "can't set attribute"
-    )
+    msg = "Can't set attribute"
     with pytest.raises(AttributeError, match=msg):
         idx.levels = new_levels
 

From 572acefe24d1e3dad59439b6ef36f2c231c1d061 Mon Sep 17 00:00:00 2001
From: Fangchen Li <fangchen.li@outlook.com>
Date: Fri, 24 Jun 2022 15:34:54 -0700
Subject: [PATCH 07/26] xfail and skip tests

---
 pandas/tests/io/parser/common/test_read_errors.py | 3 ++-
 pandas/tests/io/parser/test_quoting.py            | 5 +++++
 pandas/tests/scalar/test_nat.py                   | 2 ++
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/pandas/tests/io/parser/common/test_read_errors.py b/pandas/tests/io/parser/common/test_read_errors.py
index 47f1052808e0c..57db65b42464b 100644
--- a/pandas/tests/io/parser/common/test_read_errors.py
+++ b/pandas/tests/io/parser/common/test_read_errors.py
@@ -12,6 +12,7 @@
 import numpy as np
 import pytest
 
+from pandas.compat import PY311
 from pandas.errors import (
     EmptyDataError,
     ParserError,
@@ -230,7 +231,7 @@ def test_null_byte_char(all_parsers):
     names = ["a", "b"]
     parser = all_parsers
 
-    if parser.engine == "c":
+    if parser.engine == "c" or PY311:
         expected = DataFrame([[np.nan, "foo"]], columns=names)
         out = parser.read_csv(StringIO(data), names=names)
         tm.assert_frame_equal(out, expected)
diff --git a/pandas/tests/io/parser/test_quoting.py b/pandas/tests/io/parser/test_quoting.py
index 456dd049d2f4a..dd6b1b415e214 100644
--- a/pandas/tests/io/parser/test_quoting.py
+++ b/pandas/tests/io/parser/test_quoting.py
@@ -8,6 +8,7 @@
 
 import pytest
 
+from pandas.compat import PY311
 from pandas.errors import ParserError
 
 from pandas import DataFrame
@@ -79,6 +80,10 @@ def test_null_quote_char(all_parsers, quoting, quote_char):
     parser = all_parsers
 
     if quoting != csv.QUOTE_NONE:
+        if quote_char == "" and PY311:
+            pytest.xfail(
+                "Python 3.11 raises TypeError: 'quotechar' must be a 1-character string here"
+            )
         # Sanity checking.
         msg = "quotechar must be set if quoting enabled"
 
diff --git a/pandas/tests/scalar/test_nat.py b/pandas/tests/scalar/test_nat.py
index 873103b01f64d..b50e9bc6cf175 100644
--- a/pandas/tests/scalar/test_nat.py
+++ b/pandas/tests/scalar/test_nat.py
@@ -9,6 +9,7 @@
 import pytz
 
 from pandas._libs.tslibs import iNaT
+from pandas.compat import PY311
 
 from pandas.core.dtypes.common import is_datetime64_any_dtype
 
@@ -314,6 +315,7 @@ def test_overlap_public_nat_methods(klass, expected):
     assert _get_overlap_public_nat_methods(klass) == expected
 
 
+@pytest.mark.skipif(PY311, reason="error in Python 3.11")
 @pytest.mark.parametrize(
     "compare",
     (

From c5f2fe38b66df538e9827131205afceb5c11081a Mon Sep 17 00:00:00 2001
From: Fangchen Li <fangchen.li@outlook.com>
Date: Fri, 24 Jun 2022 18:12:20 -0700
Subject: [PATCH 08/26] fix error

---
 pandas/tests/io/parser/test_quoting.py | 5 +----
 pandas/tests/scalar/test_nat.py        | 2 +-
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/pandas/tests/io/parser/test_quoting.py b/pandas/tests/io/parser/test_quoting.py
index dd6b1b415e214..6b623aebfabda 100644
--- a/pandas/tests/io/parser/test_quoting.py
+++ b/pandas/tests/io/parser/test_quoting.py
@@ -72,6 +72,7 @@ def test_quote_char_various(all_parsers, quote_char):
     tm.assert_frame_equal(result, expected)
 
 
+@pytest.mark.xfail(PY311, reason="raises TypeError Python 3.11")
 @pytest.mark.parametrize("quoting", [csv.QUOTE_MINIMAL, csv.QUOTE_NONE])
 @pytest.mark.parametrize("quote_char", ["", None])
 def test_null_quote_char(all_parsers, quoting, quote_char):
@@ -80,10 +81,6 @@ def test_null_quote_char(all_parsers, quoting, quote_char):
     parser = all_parsers
 
     if quoting != csv.QUOTE_NONE:
-        if quote_char == "" and PY311:
-            pytest.xfail(
-                "Python 3.11 raises TypeError: 'quotechar' must be a 1-character string here"
-            )
         # Sanity checking.
         msg = "quotechar must be set if quoting enabled"
 
diff --git a/pandas/tests/scalar/test_nat.py b/pandas/tests/scalar/test_nat.py
index b50e9bc6cf175..8511a6d120ffc 100644
--- a/pandas/tests/scalar/test_nat.py
+++ b/pandas/tests/scalar/test_nat.py
@@ -315,7 +315,7 @@ def test_overlap_public_nat_methods(klass, expected):
     assert _get_overlap_public_nat_methods(klass) == expected
 
 
-@pytest.mark.skipif(PY311, reason="error in Python 3.11")
+@pytest.mark.xfail(PY311, reason="error in Python 3.11", raises=TypeError)
 @pytest.mark.parametrize(
     "compare",
     (

From 69ea5eda740f75047c134eeee588df01b59fd76a Mon Sep 17 00:00:00 2001
From: Fangchen Li <fangchen.li@outlook.com>
Date: Fri, 24 Jun 2022 21:55:24 -0700
Subject: [PATCH 09/26] roll back

---
 pandas/tests/io/parser/test_quoting.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/pandas/tests/io/parser/test_quoting.py b/pandas/tests/io/parser/test_quoting.py
index 6b623aebfabda..8326a07ac5aee 100644
--- a/pandas/tests/io/parser/test_quoting.py
+++ b/pandas/tests/io/parser/test_quoting.py
@@ -72,7 +72,6 @@ def test_quote_char_various(all_parsers, quote_char):
     tm.assert_frame_equal(result, expected)
 
 
-@pytest.mark.xfail(PY311, reason="raises TypeError Python 3.11")
 @pytest.mark.parametrize("quoting", [csv.QUOTE_MINIMAL, csv.QUOTE_NONE])
 @pytest.mark.parametrize("quote_char", ["", None])
 def test_null_quote_char(all_parsers, quoting, quote_char):

From 267c9f2002289465e0b0b32c6fbc723f45d7a428 Mon Sep 17 00:00:00 2001
From: Fangchen Li <fangchen.li@outlook.com>
Date: Sat, 2 Jul 2022 09:30:01 -0700
Subject: [PATCH 10/26] revert

---
 pandas/tests/io/parser/common/test_read_errors.py | 3 +--
 pandas/tests/io/parser/test_quoting.py            | 1 -
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/pandas/tests/io/parser/common/test_read_errors.py b/pandas/tests/io/parser/common/test_read_errors.py
index 57db65b42464b..47f1052808e0c 100644
--- a/pandas/tests/io/parser/common/test_read_errors.py
+++ b/pandas/tests/io/parser/common/test_read_errors.py
@@ -12,7 +12,6 @@
 import numpy as np
 import pytest
 
-from pandas.compat import PY311
 from pandas.errors import (
     EmptyDataError,
     ParserError,
@@ -231,7 +230,7 @@ def test_null_byte_char(all_parsers):
     names = ["a", "b"]
     parser = all_parsers
 
-    if parser.engine == "c" or PY311:
+    if parser.engine == "c":
         expected = DataFrame([[np.nan, "foo"]], columns=names)
         out = parser.read_csv(StringIO(data), names=names)
         tm.assert_frame_equal(out, expected)
diff --git a/pandas/tests/io/parser/test_quoting.py b/pandas/tests/io/parser/test_quoting.py
index 8326a07ac5aee..456dd049d2f4a 100644
--- a/pandas/tests/io/parser/test_quoting.py
+++ b/pandas/tests/io/parser/test_quoting.py
@@ -8,7 +8,6 @@
 
 import pytest
 
-from pandas.compat import PY311
 from pandas.errors import ParserError
 
 from pandas import DataFrame

From 77dab8a683903d47e86587142058d4c6a4aea35a Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Sat, 6 Aug 2022 07:49:25 -0700
Subject: [PATCH 11/26] maybe fix errors

---
 pandas/tests/io/parser/common/test_read_errors.py |  3 ++-
 pandas/tests/io/parser/test_quoting.py            | 10 ++++++++--
 pandas/tests/scalar/test_nat.py                   |  2 --
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/pandas/tests/io/parser/common/test_read_errors.py b/pandas/tests/io/parser/common/test_read_errors.py
index 47f1052808e0c..48b8efa0e5adf 100644
--- a/pandas/tests/io/parser/common/test_read_errors.py
+++ b/pandas/tests/io/parser/common/test_read_errors.py
@@ -12,6 +12,7 @@
 import numpy as np
 import pytest
 
+from pandas.compat import PY311
 from pandas.errors import (
     EmptyDataError,
     ParserError,
@@ -230,7 +231,7 @@ def test_null_byte_char(all_parsers):
     names = ["a", "b"]
     parser = all_parsers
 
-    if parser.engine == "c":
+    if parser.engine == "c" or (parser.engine == "python" and PY311):
         expected = DataFrame([[np.nan, "foo"]], columns=names)
         out = parser.read_csv(StringIO(data), names=names)
         tm.assert_frame_equal(out, expected)
diff --git a/pandas/tests/io/parser/test_quoting.py b/pandas/tests/io/parser/test_quoting.py
index a1aba949e74fe..112983c67fe04 100644
--- a/pandas/tests/io/parser/test_quoting.py
+++ b/pandas/tests/io/parser/test_quoting.py
@@ -8,6 +8,7 @@
 
 import pytest
 
+from pandas.compat import PY311
 from pandas.errors import ParserError
 
 from pandas import DataFrame
@@ -80,11 +81,16 @@ def test_null_quote_char(all_parsers, quoting, quote_char):
 
     if quoting != csv.QUOTE_NONE:
         # Sanity checking.
-        msg = "quotechar must be set if quoting enabled"
+        msg = (
+            "quotechar must be set if quoting enabled"
+            if PY311 and all_parsers.engine == "python"
+            else "quotechar must be set if quoting enabled"
+        )
 
         with pytest.raises(TypeError, match=msg):
             parser.read_csv(StringIO(data), **kwargs)
-    else:
+    elif not (PY311 and all_parsers.engine == "python"):
+        # Python 3.11+ doesn't support no quote chars in their csv parsers
         expected = DataFrame([[1, 2, 3]], columns=["a", "b", "c"])
         result = parser.read_csv(StringIO(data), **kwargs)
         tm.assert_frame_equal(result, expected)
diff --git a/pandas/tests/scalar/test_nat.py b/pandas/tests/scalar/test_nat.py
index 1e7cdecfe442d..1a07c02f4024a 100644
--- a/pandas/tests/scalar/test_nat.py
+++ b/pandas/tests/scalar/test_nat.py
@@ -9,7 +9,6 @@
 import pytz
 
 from pandas._libs.tslibs import iNaT
-from pandas.compat import PY311
 
 from pandas.core.dtypes.common import is_datetime64_any_dtype
 
@@ -315,7 +314,6 @@ def test_overlap_public_nat_methods(klass, expected):
     assert _get_overlap_public_nat_methods(klass) == expected
 
 
-@pytest.mark.xfail(PY311, reason="error in Python 3.11", raises=TypeError)
 @pytest.mark.parametrize(
     "compare",
     (

From bc1a776224d8dae8f3d135042d6eed7cd2a54322 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Sat, 6 Aug 2022 10:32:55 -0700
Subject: [PATCH 12/26] update

---
 pandas/tests/io/parser/common/test_read_errors.py | 2 +-
 pandas/tests/io/parser/test_quoting.py            | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas/tests/io/parser/common/test_read_errors.py b/pandas/tests/io/parser/common/test_read_errors.py
index 48b8efa0e5adf..93356840bb8db 100644
--- a/pandas/tests/io/parser/common/test_read_errors.py
+++ b/pandas/tests/io/parser/common/test_read_errors.py
@@ -234,7 +234,7 @@ def test_null_byte_char(all_parsers):
     if parser.engine == "c" or (parser.engine == "python" and PY311):
         expected = DataFrame([[np.nan, "foo"]], columns=names)
         out = parser.read_csv(StringIO(data), names=names)
-        tm.assert_frame_equal(out, expected)
+        tm.assert_frame_equal(out, expected, check_dtype=False)  # debug
     else:
         msg = "NULL byte detected"
         with pytest.raises(ParserError, match=msg):
diff --git a/pandas/tests/io/parser/test_quoting.py b/pandas/tests/io/parser/test_quoting.py
index 112983c67fe04..0d199e2482603 100644
--- a/pandas/tests/io/parser/test_quoting.py
+++ b/pandas/tests/io/parser/test_quoting.py
@@ -82,7 +82,7 @@ def test_null_quote_char(all_parsers, quoting, quote_char):
     if quoting != csv.QUOTE_NONE:
         # Sanity checking.
         msg = (
-            "quotechar must be set if quoting enabled"
+            '"quotechar" must be a 1-character string'
             if PY311 and all_parsers.engine == "python"
             else "quotechar must be set if quoting enabled"
         )

From ad5eef17d06fb07dde4917b33a9f410727cf1c62 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Sun, 7 Aug 2022 08:36:29 -0700
Subject: [PATCH 13/26] try something

---
 pandas/tests/io/parser/common/test_read_errors.py | 12 +++++++++---
 pandas/tests/io/parser/test_quoting.py            |  2 +-
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/pandas/tests/io/parser/common/test_read_errors.py b/pandas/tests/io/parser/common/test_read_errors.py
index 93356840bb8db..64feef6e27674 100644
--- a/pandas/tests/io/parser/common/test_read_errors.py
+++ b/pandas/tests/io/parser/common/test_read_errors.py
@@ -225,16 +225,22 @@ def test_read_csv_wrong_num_columns(all_parsers):
         parser.read_csv(StringIO(data))
 
 
-def test_null_byte_char(all_parsers):
+def test_null_byte_char(request, all_parsers):
     # see gh-2741
     data = "\x00,foo"
     names = ["a", "b"]
     parser = all_parsers
 
-    if parser.engine == "c" or (parser.engine == "python" and PY311):
+    if parser.engine in ["c", "python"]:
+        if parser.engine == "python" and PY311:
+            request.node.add_marker(
+                pytest.mark.xfail(
+                    reason="In Python 3.11, this is read as an empty character not null"
+                )
+            )
         expected = DataFrame([[np.nan, "foo"]], columns=names)
         out = parser.read_csv(StringIO(data), names=names)
-        tm.assert_frame_equal(out, expected, check_dtype=False)  # debug
+        tm.assert_frame_equal(out, expected)
     else:
         msg = "NULL byte detected"
         with pytest.raises(ParserError, match=msg):
diff --git a/pandas/tests/io/parser/test_quoting.py b/pandas/tests/io/parser/test_quoting.py
index 0d199e2482603..2d4bf338d2915 100644
--- a/pandas/tests/io/parser/test_quoting.py
+++ b/pandas/tests/io/parser/test_quoting.py
@@ -83,7 +83,7 @@ def test_null_quote_char(all_parsers, quoting, quote_char):
         # Sanity checking.
         msg = (
             '"quotechar" must be a 1-character string'
-            if PY311 and all_parsers.engine == "python"
+            if PY311 and all_parsers.engine == "python" and quote_char == ""
             else "quotechar must be set if quoting enabled"
         )
 

From 71ab88da5ebdc14cda81ae3c1db6cf04b3b12b50 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Mon, 8 Aug 2022 06:34:01 -0700
Subject: [PATCH 14/26] pin hypothesis

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

diff --git a/.github/workflows/python-dev.yml b/.github/workflows/python-dev.yml
index 1c9508c6ec440..5139e4758d7c5 100644
--- a/.github/workflows/python-dev.yml
+++ b/.github/workflows/python-dev.yml
@@ -55,7 +55,7 @@ jobs:
         python -m pip install git+https://github.com/cython/cython.git
         python -m pip install git+https://github.com/numpy/numpy.git
         python -m pip install git+https://github.com/nedbat/coveragepy.git
-        python -m pip install python-dateutil pytz hypothesis pytest>=6.2.5 pytest-xdist pytest-cov pytest-asyncio>=0.17
+        python -m pip install python-dateutil pytz hypothesis==6.52.3 pytest>=6.2.5 pytest-xdist pytest-cov pytest-asyncio>=0.17
         python -m pip list
 
     - name: Build Pandas

From aca30a08448515080d91d988227b8ef5f275e458 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Mon, 8 Aug 2022 14:10:40 -0700
Subject: [PATCH 15/26] Don't check parentheses equality

---
 setup.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/setup.py b/setup.py
index 70adbd3c083af..0a8d89143369e 100755
--- a/setup.py
+++ b/setup.py
@@ -335,7 +335,7 @@ def run(self):
 else:
     # PANDAS_CI=1 is set in CI
     if os.environ.get("PANDAS_CI", "0") == "1":
-        extra_compile_args.append("-Werror")
+        extra_compile_args.append(["-Werror", "-Wno-parentheses-equality"])
     if debugging_symbols_requested:
         extra_compile_args.append("-g")
         extra_compile_args.append("-UNDEBUG")

From 11c9269e62a786d9bcc2588bbfba925352dd9b58 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Mon, 8 Aug 2022 14:19:27 -0700
Subject: [PATCH 16/26] typo

---
 setup.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/setup.py b/setup.py
index 0a8d89143369e..c1b087bc78e31 100755
--- a/setup.py
+++ b/setup.py
@@ -335,7 +335,7 @@ def run(self):
 else:
     # PANDAS_CI=1 is set in CI
     if os.environ.get("PANDAS_CI", "0") == "1":
-        extra_compile_args.append(["-Werror", "-Wno-parentheses-equality"])
+        extra_compile_args += ["-Werror", "-Wno-parentheses-equality"]
     if debugging_symbols_requested:
         extra_compile_args.append("-g")
         extra_compile_args.append("-UNDEBUG")

From 5cfb0719e06a383f2292dac524cf2db955b886d5 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Mon, 8 Aug 2022 14:39:56 -0700
Subject: [PATCH 17/26] pin cython

---
 .github/workflows/python-dev.yml | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/.github/workflows/python-dev.yml b/.github/workflows/python-dev.yml
index 5139e4758d7c5..b714e4d2988d1 100644
--- a/.github/workflows/python-dev.yml
+++ b/.github/workflows/python-dev.yml
@@ -52,10 +52,9 @@ jobs:
       run: |
         python --version
         python -m pip install --upgrade pip setuptools wheel
-        python -m pip install git+https://github.com/cython/cython.git
         python -m pip install git+https://github.com/numpy/numpy.git
         python -m pip install git+https://github.com/nedbat/coveragepy.git
-        python -m pip install python-dateutil pytz hypothesis==6.52.3 pytest>=6.2.5 pytest-xdist pytest-cov pytest-asyncio>=0.17
+        python -m pip install python-dateutil pytz cython hypothesis==6.52.3 pytest>=6.2.5 pytest-xdist pytest-cov pytest-asyncio>=0.17
         python -m pip list
 
     - name: Build Pandas

From 668c53eda8c1705e91bf351686f54186c385cf34 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Mon, 8 Aug 2022 20:33:09 -0700
Subject: [PATCH 18/26] correctly pin hypothesis

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

diff --git a/.github/workflows/python-dev.yml b/.github/workflows/python-dev.yml
index b714e4d2988d1..fd7341896c565 100644
--- a/.github/workflows/python-dev.yml
+++ b/.github/workflows/python-dev.yml
@@ -54,7 +54,7 @@ jobs:
         python -m pip install --upgrade pip setuptools wheel
         python -m pip install git+https://github.com/numpy/numpy.git
         python -m pip install git+https://github.com/nedbat/coveragepy.git
-        python -m pip install python-dateutil pytz cython hypothesis==6.52.3 pytest>=6.2.5 pytest-xdist pytest-cov pytest-asyncio>=0.17
+        python -m pip install python-dateutil pytz cython hypothesis==6.52.1 pytest>=6.2.5 pytest-xdist pytest-cov pytest-asyncio>=0.17
         python -m pip list
 
     - name: Build Pandas

From 827a6483d875a88d0598c2c42eced43a102f0f8d Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Wed, 10 Aug 2022 14:48:24 -0700
Subject: [PATCH 19/26] adjust test

---
 pandas/tests/io/parser/common/test_read_errors.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/tests/io/parser/common/test_read_errors.py b/pandas/tests/io/parser/common/test_read_errors.py
index 64feef6e27674..f52af109626e9 100644
--- a/pandas/tests/io/parser/common/test_read_errors.py
+++ b/pandas/tests/io/parser/common/test_read_errors.py
@@ -231,7 +231,7 @@ def test_null_byte_char(request, all_parsers):
     names = ["a", "b"]
     parser = all_parsers
 
-    if parser.engine in ["c", "python"]:
+    if parser.engine == "c" or (parser.engine == "python" and PY311):
         if parser.engine == "python" and PY311:
             request.node.add_marker(
                 pytest.mark.xfail(

From 5fb3daabd808a5bba41b856de7a72b2d6d3a4fc2 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Wed, 10 Aug 2022 15:41:03 -0700
Subject: [PATCH 20/26] remove compiler flag

---
 setup.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/setup.py b/setup.py
index c1b087bc78e31..70adbd3c083af 100755
--- a/setup.py
+++ b/setup.py
@@ -335,7 +335,7 @@ def run(self):
 else:
     # PANDAS_CI=1 is set in CI
     if os.environ.get("PANDAS_CI", "0") == "1":
-        extra_compile_args += ["-Werror", "-Wno-parentheses-equality"]
+        extra_compile_args.append("-Werror")
     if debugging_symbols_requested:
         extra_compile_args.append("-g")
         extra_compile_args.append("-UNDEBUG")

From b1a58fe6d98529741e9ece0fbe780cb7bf658920 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Thu, 11 Aug 2022 10:11:27 -0700
Subject: [PATCH 21/26] typo'ed

---
 pandas/tests/io/parser/test_quoting.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/tests/io/parser/test_quoting.py b/pandas/tests/io/parser/test_quoting.py
index 2d4bf338d2915..025a612dc47d2 100644
--- a/pandas/tests/io/parser/test_quoting.py
+++ b/pandas/tests/io/parser/test_quoting.py
@@ -90,7 +90,7 @@ def test_null_quote_char(all_parsers, quoting, quote_char):
         with pytest.raises(TypeError, match=msg):
             parser.read_csv(StringIO(data), **kwargs)
     elif not (PY311 and all_parsers.engine == "python"):
-        # Python 3.11+ doesn't support no quote chars in their csv parsers
+        # Python 3.11+ doesn't support null/blank quote chars in their csv parsers
         expected = DataFrame([[1, 2, 3]], columns=["a", "b", "c"])
         result = parser.read_csv(StringIO(data), **kwargs)
         tm.assert_frame_equal(result, expected)

From 354b12c8102872762b564424de47f47e08d79446 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Mon, 15 Aug 2022 10:00:13 -0700
Subject: [PATCH 22/26] fix tests

---
 pandas/tests/indexes/datetimes/test_constructors.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/pandas/tests/indexes/datetimes/test_constructors.py b/pandas/tests/indexes/datetimes/test_constructors.py
index 086cb18dbe463..26b98d821b6ba 100644
--- a/pandas/tests/indexes/datetimes/test_constructors.py
+++ b/pandas/tests/indexes/datetimes/test_constructors.py
@@ -1137,8 +1137,10 @@ def test_timestamp_constructor_retain_fold(tz, fold):
 
 _tzs = ["dateutil/Europe/London"]
 if PY39:
-    _tzs = ["dateutil/Europe/London", zoneinfo.ZoneInfo("Europe/London")]
-
+    try:
+        _tzs = ["dateutil/Europe/London", zoneinfo.ZoneInfo("Europe/London")]
+    except zoneinfo.ZoneInfoNotFoundError:
+        pass
 
 @pytest.mark.parametrize("tz", _tzs)
 @pytest.mark.parametrize(

From 54023de8e62aa17f477e95b306564b2b3c47ee0f Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Mon, 15 Aug 2022 11:24:45 -0700
Subject: [PATCH 23/26] linter

---
 pandas/tests/indexes/datetimes/test_constructors.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pandas/tests/indexes/datetimes/test_constructors.py b/pandas/tests/indexes/datetimes/test_constructors.py
index 26b98d821b6ba..1d161630b1356 100644
--- a/pandas/tests/indexes/datetimes/test_constructors.py
+++ b/pandas/tests/indexes/datetimes/test_constructors.py
@@ -1142,6 +1142,7 @@ def test_timestamp_constructor_retain_fold(tz, fold):
     except zoneinfo.ZoneInfoNotFoundError:
         pass
 
+
 @pytest.mark.parametrize("tz", _tzs)
 @pytest.mark.parametrize(
     "ts_input,fold_out",

From 9adcc80e66653b77e4de2b128cefd47d6f7b07d0 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Wed, 17 Aug 2022 11:05:35 -0700
Subject: [PATCH 24/26] clarify freeze/unfreeze instructions

---
 .github/workflows/python-dev.yml | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/.github/workflows/python-dev.yml b/.github/workflows/python-dev.yml
index fd7341896c565..27e66aeb996b5 100644
--- a/.github/workflows/python-dev.yml
+++ b/.github/workflows/python-dev.yml
@@ -1,3 +1,23 @@
+# This workflow may or may not run depending on the state of the next
+# unreleased Python version. DO NOT DELETE IT.
+# 
+# In general, this file will remain frozen(present, but not running) until:
+#    - The next unreleased Python version has released beta 1
+#      - This version should be available on Github Actions.
+#    - Our required build/runtime dependencies(numpy, pytz, Cython, python-dateutil) 
+#      support that unreleased Python version.
+#    To unfreeze, comment out the ``if: false`` condition, and make sure you update 
+#    the name of the workflow and Python version in actions/setup-python to: '3.12-dev'
+# 
+# After it has been unfrozen, this file should remain unfrozen(present, and running) until:
+#    - The next Python version has been officially released.
+#    OR 
+#    - Most/All of our optional dependencies support Python 3.11 AND
+#    - The next Python version has released a rc(we are guaranteed a stable ABI).
+#    To freeze this file, uncomment out the ``if: false`` condition, and migrate the jobs
+#    to the corresponding posix/windows-macos/sdist etc. workflows.
+# Feel free to modify this comment as necessary.
+
 name: Python Dev
 
 on:
@@ -24,6 +44,7 @@ permissions:
 
 jobs:
   build:
+    # if: false # Uncomment this to freeze the workflow, comment it to unfreeze
     runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false

From ce6a0a4ad9fb4f73872e338673a6e21650d6293a Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Wed, 17 Aug 2022 11:42:36 -0700
Subject: [PATCH 25/26] whitespace

---
 .github/workflows/python-dev.yml | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/.github/workflows/python-dev.yml b/.github/workflows/python-dev.yml
index 27e66aeb996b5..f495f46dfdc63 100644
--- a/.github/workflows/python-dev.yml
+++ b/.github/workflows/python-dev.yml
@@ -1,17 +1,17 @@
 # This workflow may or may not run depending on the state of the next
 # unreleased Python version. DO NOT DELETE IT.
-# 
+#
 # In general, this file will remain frozen(present, but not running) until:
 #    - The next unreleased Python version has released beta 1
 #      - This version should be available on Github Actions.
-#    - Our required build/runtime dependencies(numpy, pytz, Cython, python-dateutil) 
+#    - Our required build/runtime dependencies(numpy, pytz, Cython, python-dateutil)
 #      support that unreleased Python version.
-#    To unfreeze, comment out the ``if: false`` condition, and make sure you update 
+#    To unfreeze, comment out the ``if: false`` condition, and make sure you update
 #    the name of the workflow and Python version in actions/setup-python to: '3.12-dev'
 # 
 # After it has been unfrozen, this file should remain unfrozen(present, and running) until:
 #    - The next Python version has been officially released.
-#    OR 
+#    OR
 #    - Most/All of our optional dependencies support Python 3.11 AND
 #    - The next Python version has released a rc(we are guaranteed a stable ABI).
 #    To freeze this file, uncomment out the ``if: false`` condition, and migrate the jobs

From 0b3278227e75439c4fe86dee826c90d2942b8c7d Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Wed, 17 Aug 2022 12:18:54 -0700
Subject: [PATCH 26/26] one more

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

diff --git a/.github/workflows/python-dev.yml b/.github/workflows/python-dev.yml
index f495f46dfdc63..580cafd6e4949 100644
--- a/.github/workflows/python-dev.yml
+++ b/.github/workflows/python-dev.yml
@@ -8,7 +8,7 @@
 #      support that unreleased Python version.
 #    To unfreeze, comment out the ``if: false`` condition, and make sure you update
 #    the name of the workflow and Python version in actions/setup-python to: '3.12-dev'
-# 
+#
 # After it has been unfrozen, this file should remain unfrozen(present, and running) until:
 #    - The next Python version has been officially released.
 #    OR