From bb520d105f0a2ade434dde713bad6feaab50e485 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Mon, 15 Jan 2024 12:07:54 -0800
Subject: [PATCH 01/13] add warning

---
 pandas/__init__.py | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/pandas/__init__.py b/pandas/__init__.py
index 7fab662ed2de4..e11ae0f13a6e3 100644
--- a/pandas/__init__.py
+++ b/pandas/__init__.py
@@ -205,6 +205,25 @@
 # Don't allow users to use pandas.os or pandas.warnings
 del os, warnings
 
+# DeprecationWarning for missing pyarrow
+from pandas.compat.pyarrow import pa_version_under10p1
+
+if not pa_version_under10p1:
+    import warnings
+    from pandas.compat._optional import VERSIONS
+
+    warnings.warn(
+        "Pyarrow will become a future required dependency of pandas,"
+        "but was not found to be installed on your system."
+        f"(or was too old - pyarrow {VERSIONS['pyarrow']} is the current"
+        f"minimum supported version as of this release)"
+        "If this would cause problems for you, "
+        "please provide us feedback at https://github.com/pandas-dev/pandas/issues/54466",
+        DeprecationWarning,
+        stacklevel=2,
+    )
+del pa_version_under10p1
+
 # module level doc-string
 __doc__ = """
 pandas - a powerful data analysis and manipulation library for Python

From a3b3dc3c30d279f3f35b160e5bc64613cc991e55 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Mon, 15 Jan 2024 13:26:09 -0800
Subject: [PATCH 02/13] DEPS: Add warning if pyarrow is not installed

---
 pandas/__init__.py | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/pandas/__init__.py b/pandas/__init__.py
index e11ae0f13a6e3..251e7b6732bf8 100644
--- a/pandas/__init__.py
+++ b/pandas/__init__.py
@@ -208,17 +208,19 @@
 # DeprecationWarning for missing pyarrow
 from pandas.compat.pyarrow import pa_version_under10p1
 
-if not pa_version_under10p1:
+if pa_version_under10p1:
     import warnings
     from pandas.compat._optional import VERSIONS
 
     warnings.warn(
-        "Pyarrow will become a future required dependency of pandas,"
-        "but was not found to be installed on your system."
-        f"(or was too old - pyarrow {VERSIONS['pyarrow']} is the current"
-        f"minimum supported version as of this release)"
-        "If this would cause problems for you, "
-        "please provide us feedback at https://github.com/pandas-dev/pandas/issues/54466",
+        f"""
+Pyarrow will become a future required dependency of pandas,
+but was not found to be installed on your system.
+(or was too old-pyarrow {VERSIONS['pyarrow']}
+is the current minimum supported version as of this release)
+If this would cause problems for you,
+please provide us feedback at https://github.com/pandas-dev/pandas/issues/54466
+        """,
         DeprecationWarning,
         stacklevel=2,
     )

From 944c2887c5c860428157ec02215cf98aefd18c75 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Mon, 15 Jan 2024 13:29:05 -0800
Subject: [PATCH 03/13] formatting

---
 pandas/__init__.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/__init__.py b/pandas/__init__.py
index 251e7b6732bf8..ede56920756d6 100644
--- a/pandas/__init__.py
+++ b/pandas/__init__.py
@@ -216,7 +216,7 @@
         f"""
 Pyarrow will become a future required dependency of pandas,
 but was not found to be installed on your system.
-(or was too old-pyarrow {VERSIONS['pyarrow']}
+(or was too old - pyarrow {VERSIONS['pyarrow']}
 is the current minimum supported version as of this release)
 If this would cause problems for you,
 please provide us feedback at https://github.com/pandas-dev/pandas/issues/54466

From 613eac784f37528c11e4b89698c418ab93f5bb53 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Mon, 15 Jan 2024 20:09:42 -0800
Subject: [PATCH 04/13] Update __init__.py

---
 pandas/__init__.py | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pandas/__init__.py b/pandas/__init__.py
index ede56920756d6..70f5dcb3d1088 100644
--- a/pandas/__init__.py
+++ b/pandas/__init__.py
@@ -202,8 +202,8 @@
         FutureWarning,
         stacklevel=2,
     )
-# Don't allow users to use pandas.os or pandas.warnings
-del os, warnings
+# Don't allow users to use pandas.os
+del os
 
 # DeprecationWarning for missing pyarrow
 from pandas.compat.pyarrow import pa_version_under10p1
@@ -224,7 +224,7 @@
         DeprecationWarning,
         stacklevel=2,
     )
-del pa_version_under10p1
+del pa_version_under10p1, warnings
 
 # module level doc-string
 __doc__ = """

From 21509c5021377861bf017430689eac04c8ca1958 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Tue, 16 Jan 2024 16:41:24 -0800
Subject: [PATCH 05/13] adjustments

---
 pandas/__init__.py | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/pandas/__init__.py b/pandas/__init__.py
index 70f5dcb3d1088..321a8f2b7fd76 100644
--- a/pandas/__init__.py
+++ b/pandas/__init__.py
@@ -209,21 +209,31 @@
 from pandas.compat.pyarrow import pa_version_under10p1
 
 if pa_version_under10p1:
-    import warnings
+    # Check if old pyarrow is installed
     from pandas.compat._optional import VERSIONS
 
+    try:
+        import pyarrow  # noqa: F401
+
+        pa_msg = (
+            f"was too old on your system - pyarrow {VERSIONS['pyarrow']} "
+            "is the current minimum supported version as of this release."
+        )
+    except ImportError:
+        pa_msg = "was not found to be installed on your system."
+
     warnings.warn(
         f"""
 Pyarrow will become a future required dependency of pandas,
-but was not found to be installed on your system.
-(or was too old - pyarrow {VERSIONS['pyarrow']}
-is the current minimum supported version as of this release)
+(to allow more performant data types and better interoperability with other libraries)
+but {pa_msg}
 If this would cause problems for you,
 please provide us feedback at https://github.com/pandas-dev/pandas/issues/54466
         """,
         DeprecationWarning,
         stacklevel=2,
     )
+    del VERSIONS
 del pa_version_under10p1, warnings
 
 # module level doc-string

From c6ae03d009b60c1f1dec961abe2d35e4e8557878 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Tue, 16 Jan 2024 16:42:42 -0800
Subject: [PATCH 06/13] adjustments

---
 pandas/__init__.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/__init__.py b/pandas/__init__.py
index 321a8f2b7fd76..9d3056e20d58d 100644
--- a/pandas/__init__.py
+++ b/pandas/__init__.py
@@ -224,7 +224,7 @@
 
     warnings.warn(
         f"""
-Pyarrow will become a future required dependency of pandas,
+Pyarrow will become a required dependency of pandas in the next major release of pandas,
 (to allow more performant data types and better interoperability with other libraries)
 but {pa_msg}
 If this would cause problems for you,

From 7b48501623859807088c5820df884ed341086866 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Wed, 17 Jan 2024 07:42:11 -0800
Subject: [PATCH 07/13] updates

---
 pandas/__init__.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/pandas/__init__.py b/pandas/__init__.py
index 9d3056e20d58d..2c3ccb7e65e41 100644
--- a/pandas/__init__.py
+++ b/pandas/__init__.py
@@ -202,8 +202,6 @@
         FutureWarning,
         stacklevel=2,
     )
-# Don't allow users to use pandas.os
-del os
 
 # DeprecationWarning for missing pyarrow
 from pandas.compat.pyarrow import pa_version_under10p1
@@ -213,12 +211,13 @@
     from pandas.compat._optional import VERSIONS
 
     try:
-        import pyarrow  # noqa: F401
+        import pyarrow
 
         pa_msg = (
             f"was too old on your system - pyarrow {VERSIONS['pyarrow']} "
             "is the current minimum supported version as of this release."
         )
+        del pyarrow
     except ImportError:
         pa_msg = "was not found to be installed on your system."
 
@@ -234,7 +233,9 @@
         stacklevel=2,
     )
     del VERSIONS
-del pa_version_under10p1, warnings
+
+# Delete all unnecessary imported modules
+del pa_version_under10p1, warnings, os
 
 # module level doc-string
 __doc__ = """

From 199fb7c7dd65fb6a903e00618fdd4b60a34f62e0 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Wed, 17 Jan 2024 10:18:42 -0800
Subject: [PATCH 08/13] address code review

---
 pandas/__init__.py          | 21 +++++++++------------
 pandas/compat/pyarrow.py    |  2 ++
 pandas/tests/test_common.py | 23 +++++++++++++++++++++++
 3 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/pandas/__init__.py b/pandas/__init__.py
index 2c3ccb7e65e41..33612a894d038 100644
--- a/pandas/__init__.py
+++ b/pandas/__init__.py
@@ -204,38 +204,35 @@
     )
 
 # DeprecationWarning for missing pyarrow
-from pandas.compat.pyarrow import pa_version_under10p1
+from pandas.compat.pyarrow import pa_version_under10p1, pa_not_found
 
 if pa_version_under10p1:
-    # Check if old pyarrow is installed
+    # pyarrow is either too old or nonexistent, warn
     from pandas.compat._optional import VERSIONS
 
-    try:
-        import pyarrow
-
+    if pa_not_found:
+        pa_msg = "was not found to be installed on your system."
+    else:
         pa_msg = (
             f"was too old on your system - pyarrow {VERSIONS['pyarrow']} "
             "is the current minimum supported version as of this release."
         )
-        del pyarrow
-    except ImportError:
-        pa_msg = "was not found to be installed on your system."
 
     warnings.warn(
         f"""
-Pyarrow will become a required dependency of pandas in the next major release of pandas,
-(to allow more performant data types and better interoperability with other libraries)
+Pyarrow will become a required dependency of pandas in the next major release of pandas (pandas 3.0),
+(to allow more performant data types, such as the Arrow string type, and better interoperability with other libraries)
 but {pa_msg}
 If this would cause problems for you,
 please provide us feedback at https://github.com/pandas-dev/pandas/issues/54466
-        """,
+        """,  # noqa: E501
         DeprecationWarning,
         stacklevel=2,
     )
     del VERSIONS
 
 # Delete all unnecessary imported modules
-del pa_version_under10p1, warnings, os
+del pa_version_under10p1, pa_not_found, warnings, os
 
 # module level doc-string
 __doc__ = """
diff --git a/pandas/compat/pyarrow.py b/pandas/compat/pyarrow.py
index beb4814914101..2e151123ef2c9 100644
--- a/pandas/compat/pyarrow.py
+++ b/pandas/compat/pyarrow.py
@@ -8,6 +8,7 @@
     import pyarrow as pa
 
     _palv = Version(Version(pa.__version__).base_version)
+    pa_not_found = False
     pa_version_under10p1 = _palv < Version("10.0.1")
     pa_version_under11p0 = _palv < Version("11.0.0")
     pa_version_under12p0 = _palv < Version("12.0.0")
@@ -16,6 +17,7 @@
     pa_version_under14p1 = _palv < Version("14.0.1")
     pa_version_under15p0 = _palv < Version("15.0.0")
 except ImportError:
+    pa_not_found = True
     pa_version_under10p1 = True
     pa_version_under11p0 = True
     pa_version_under12p0 = True
diff --git a/pandas/tests/test_common.py b/pandas/tests/test_common.py
index e8a1c961c8cb6..00dca96799b05 100644
--- a/pandas/tests/test_common.py
+++ b/pandas/tests/test_common.py
@@ -265,3 +265,26 @@ def test_bz2_missing_import():
     code = textwrap.dedent(code)
     call = [sys.executable, "-c", code]
     subprocess.check_output(call)
+
+
+import pandas.util._test_decorators as td
+
+
+@td.skip_if_installed("pyarrow")
+@pytest.mark.parametrize("module", ["pandas", "pandas.arrays"])
+def test_pyarrow_missing_warn(module):
+    # GH56896
+    response = subprocess.run(
+        [sys.executable, "-c", f"import {module}"],
+        capture_output=True,
+        check=True,
+    )
+    msg = """
+Pyarrow will become a required dependency of pandas in the next major release of pandas (pandas 3.0),
+(to allow more performant data types, such as the Arrow string type, and better interoperability with other libraries)
+but was not found to be installed on your system.
+If this would cause problems for you,
+please provide us feedback at https://github.com/pandas-dev/pandas/issues/54466
+"""  # noqa: E501
+    stderr_msg = response.stderr.decode("utf-8")
+    assert msg in stderr_msg, stderr_msg

From 4637a96afcb582dec8d6ac7cdb3405d6efe0365a Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Wed, 17 Jan 2024 11:28:38 -0800
Subject: [PATCH 09/13] Update __init__.py

---
 pandas/__init__.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pandas/__init__.py b/pandas/__init__.py
index 33612a894d038..ed524c2bb3619 100644
--- a/pandas/__init__.py
+++ b/pandas/__init__.py
@@ -229,7 +229,7 @@
         DeprecationWarning,
         stacklevel=2,
     )
-    del VERSIONS
+    del VERSIONS, pa_msg
 
 # Delete all unnecessary imported modules
 del pa_version_under10p1, pa_not_found, warnings, os

From aa48e193f438e762d8f40fc9b3e4b6e471c8af0c Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Thu, 18 Jan 2024 16:21:49 -0800
Subject: [PATCH 10/13] add pyarrow to npdev build

---
 ci/deps/actions-311-numpydev.yaml | 1 +
 pandas/tests/test_common.py       | 5 ++---
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/ci/deps/actions-311-numpydev.yaml b/ci/deps/actions-311-numpydev.yaml
index b62e8630f2059..d6451cf2577fd 100644
--- a/ci/deps/actions-311-numpydev.yaml
+++ b/ci/deps/actions-311-numpydev.yaml
@@ -20,6 +20,7 @@ dependencies:
   - hypothesis>=6.46.1
 
   # pandas dependencies
+  - pyarrow>=10.0.1
   - python-dateutil
   - pytz
   - pip
diff --git a/pandas/tests/test_common.py b/pandas/tests/test_common.py
index 00dca96799b05..fe24755e8cc23 100644
--- a/pandas/tests/test_common.py
+++ b/pandas/tests/test_common.py
@@ -8,6 +8,8 @@
 import numpy as np
 import pytest
 
+import pandas.util._test_decorators as td
+
 import pandas as pd
 from pandas import Series
 import pandas._testing as tm
@@ -267,9 +269,6 @@ def test_bz2_missing_import():
     subprocess.check_output(call)
 
 
-import pandas.util._test_decorators as td
-
-
 @td.skip_if_installed("pyarrow")
 @pytest.mark.parametrize("module", ["pandas", "pandas.arrays"])
 def test_pyarrow_missing_warn(module):

From 3aa3ba95123852d3f7980ef567e556c23547103c Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Thu, 18 Jan 2024 20:53:55 -0800
Subject: [PATCH 11/13] ignore non numpy related
 deprecationwarnings/futurewarning

---
 .github/workflows/unit-tests.yml | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index dd5d090e098b0..8ade9f689db2d 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -92,7 +92,10 @@ jobs:
           - name: "Numpy Dev"
             env_file: actions-311-numpydev.yaml
             pattern: "not slow and not network and not single_cpu"
-            test_args: "-W error::DeprecationWarning -W error::FutureWarning"
+            # Currently restricted the warnings that error to Deprecation Warnings from numpy
+            #
+            # TODO:
+            test_args: "-W error::DeprecationWarning:numpy -W error::FutureWarning:numpy"
           - name: "Pyarrow Nightly"
             env_file: actions-311-pyarrownightly.yaml
             pattern: "not slow and not network and not single_cpu"

From 0074b031c6571abe2e6e43f12e1e0af3fec6c166 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Thu, 18 Jan 2024 20:54:56 -0800
Subject: [PATCH 12/13] ignore non numpy related
 deprecationwarnings/futurewarning

---
 .github/workflows/unit-tests.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index 8ade9f689db2d..a3cffb4b03b93 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -93,8 +93,8 @@ jobs:
             env_file: actions-311-numpydev.yaml
             pattern: "not slow and not network and not single_cpu"
             # Currently restricted the warnings that error to Deprecation Warnings from numpy
-            #
-            # TODO:
+            # done since pyarrow isn't compatible with numpydev always
+            # TODO: work with pyarrow to revert this?
             test_args: "-W error::DeprecationWarning:numpy -W error::FutureWarning:numpy"
           - name: "Pyarrow Nightly"
             env_file: actions-311-pyarrownightly.yaml

From cc2debf3e484ce7d553794435da39e972c8b3723 Mon Sep 17 00:00:00 2001
From: Thomas Li <47963215+lithomas1@users.noreply.github.com>
Date: Fri, 19 Jan 2024 08:00:35 -0800
Subject: [PATCH 13/13] Update actions-311-numpydev.yaml

---
 ci/deps/actions-311-numpydev.yaml | 1 -
 1 file changed, 1 deletion(-)

diff --git a/ci/deps/actions-311-numpydev.yaml b/ci/deps/actions-311-numpydev.yaml
index d6451cf2577fd..b62e8630f2059 100644
--- a/ci/deps/actions-311-numpydev.yaml
+++ b/ci/deps/actions-311-numpydev.yaml
@@ -20,7 +20,6 @@ dependencies:
   - hypothesis>=6.46.1
 
   # pandas dependencies
-  - pyarrow>=10.0.1
   - python-dateutil
   - pytz
   - pip