From 74d6ec7a3500c50e566328dd9554dd96343e2f10 Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Mon, 12 Dec 2022 20:44:54 -0500
Subject: [PATCH 1/3] Fix: Treat Generic classes as not being is_list_like
 (#49736)

* Fix: Treat Generic classes as not being is_list_like

* tst: update test to test subclass of DataFrame

* add is_list_like test for instance of generic dataframe

* combine isinstance tests

* update whatsnew with clearer message

* Update whatsnew to reference DataFrame as a class

Co-authored-by: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>

* fix whatsnew blank line

* fix whatsnew issue quotes

* move whatsnew comment from 1.5.2 to 1.5.3

Co-authored-by: Matthew Roeschke <10647082+mroeschke@users.noreply.github.com>
(cherry picked from commit e37040a54b89ebb6a1c33dbde700b57900912ff4)
---
 doc/source/whatsnew/v1.5.3.rst        |  1 +
 pandas/_libs/lib.pyx                  |  9 ++++++---
 pandas/tests/dtypes/test_inference.py | 20 ++++++++++++++++++++
 3 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/doc/source/whatsnew/v1.5.3.rst b/doc/source/whatsnew/v1.5.3.rst
index cb99495b837b2..a0c38f1f81538 100644
--- a/doc/source/whatsnew/v1.5.3.rst
+++ b/doc/source/whatsnew/v1.5.3.rst
@@ -28,6 +28,7 @@ Bug fixes
 ~~~~~~~~~
 - Bug in :meth:`.Styler.to_excel` leading to error when unrecognized ``border-style`` (e.g. ``"hair"``) provided to Excel writers (:issue:`48649`)
 - Bug when chaining several :meth:`.Styler.concat` calls, only the last styler was concatenated (:issue:`49207`)
+- Fixed bug when instantiating a :class:`DataFrame` subclass inheriting from ``typing.Generic`` that triggered a ``UserWarning`` on python 3.11 (:issue:`49649`)
 -
 
 .. ---------------------------------------------------------------------------
diff --git a/pandas/_libs/lib.pyx b/pandas/_libs/lib.pyx
index 439136d17fed2..7525033b3c168 100644
--- a/pandas/_libs/lib.pyx
+++ b/pandas/_libs/lib.pyx
@@ -1,8 +1,10 @@
 from collections import abc
 from decimal import Decimal
 from enum import Enum
-from typing import Literal
-import warnings
+from typing import (
+    Literal,
+    _GenericAlias,
+)
 
 cimport cython
 from cpython.datetime cimport (
@@ -1136,7 +1138,8 @@ cdef inline bint c_is_list_like(object obj, bint allow_sets) except -1:
         # equiv: `isinstance(obj, abc.Iterable)`
         getattr(obj, "__iter__", None) is not None and not isinstance(obj, type)
         # we do not count strings/unicode/bytes as list-like
-        and not isinstance(obj, (str, bytes))
+        # exclude Generic types that have __iter__
+        and not isinstance(obj, (str, bytes, _GenericAlias))
         # exclude zero-dimensional duck-arrays, effectively scalars
         and not (hasattr(obj, "ndim") and obj.ndim == 0)
         # exclude sets if allow_sets is False
diff --git a/pandas/tests/dtypes/test_inference.py b/pandas/tests/dtypes/test_inference.py
index f08d6b8c9feb8..948d14c1bd1f9 100644
--- a/pandas/tests/dtypes/test_inference.py
+++ b/pandas/tests/dtypes/test_inference.py
@@ -18,6 +18,10 @@
 from numbers import Number
 import re
 import sys
+from typing import (
+    Generic,
+    TypeVar,
+)
 
 import numpy as np
 import pytest
@@ -228,6 +232,22 @@ def __getitem__(self, item):
     assert not inference.is_list_like(NotListLike())
 
 
+def test_is_list_like_generic():
+    # GH 49649
+    # is_list_like was yielding false positives for Generic classes in python 3.11
+    T = TypeVar("T")
+
+    class MyDataFrame(DataFrame, Generic[T]):
+        ...
+
+    tstc = MyDataFrame[int]
+    tst = MyDataFrame[int]({"x": [1, 2, 3]})
+
+    assert not inference.is_list_like(tstc)
+    assert isinstance(tst, DataFrame)
+    assert inference.is_list_like(tst)
+
+
 def test_is_sequence():
     is_seq = inference.is_sequence
     assert is_seq((1, 2))

From 4bbbb2ee9c67f79e6a67995d3500e17398a4eab4 Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Tue, 13 Dec 2022 09:55:16 -0500
Subject: [PATCH 2/3] Force checks


From c17fd92a6d8ef31937e09d101ecd15e9fc14c995 Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Tue, 13 Dec 2022 10:26:24 -0500
Subject: [PATCH 3/3] put back import warnings in lib.pyx - got deleted when
 merged

---
 pandas/_libs/lib.pyx | 1 +
 1 file changed, 1 insertion(+)

diff --git a/pandas/_libs/lib.pyx b/pandas/_libs/lib.pyx
index 7525033b3c168..d2c2697c05812 100644
--- a/pandas/_libs/lib.pyx
+++ b/pandas/_libs/lib.pyx
@@ -5,6 +5,7 @@ from typing import (
     Literal,
     _GenericAlias,
 )
+import warnings
 
 cimport cython
 from cpython.datetime cimport (