From 0568d57932c6fd72116b9d4b9e744500c4042a72 Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Sat, 1 May 2021 19:14:44 -0400
Subject: [PATCH 1/9] TYP: Simple type fixes for ExtensionArray

---
 pandas/core/arrays/base.py | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/pandas/core/arrays/base.py b/pandas/core/arrays/base.py
index 5a2643dd531ed..62f148a68857d 100644
--- a/pandas/core/arrays/base.py
+++ b/pandas/core/arrays/base.py
@@ -13,6 +13,7 @@
     TYPE_CHECKING,
     Any,
     Callable,
+    Iterator,
     Sequence,
     TypeVar,
     cast,
@@ -69,6 +70,7 @@
 )
 
 if TYPE_CHECKING:
+    from typing import Literal
 
     class ExtensionArraySupportsAnyAll("ExtensionArray"):
         def any(self, *, skipna: bool = True) -> bool:
@@ -375,7 +377,7 @@ def __len__(self) -> int:
         """
         raise AbstractMethodError(self)
 
-    def __iter__(self):
+    def __iter__(self) -> Iterator[Any]:
         """
         Iterate over elements of the array.
         """
@@ -385,7 +387,7 @@ def __iter__(self):
         for i in range(len(self)):
             yield self[i]
 
-    def __contains__(self, item) -> bool | np.bool_:
+    def __contains__(self, item: Any) -> bool | np.bool_:
         """
         Return for `item in self`.
         """
@@ -680,7 +682,12 @@ def argmax(self, skipna: bool = True) -> int:
             raise NotImplementedError
         return nargminmax(self, "argmax")
 
-    def fillna(self, value=None, method=None, limit=None):
+    def fillna(
+        self,
+        value: Any | ArrayLike | None,
+        method: Literal["backfill", "bfill", "ffill", "pad"] | None = None,
+        limit: int | None = None,
+    ):
         """
         Fill NA/NaN values using the specified method.
 
@@ -1207,7 +1214,7 @@ def _formatter(self, boxed: bool = False) -> Callable[[Any], str | None]:
     # Reshaping
     # ------------------------------------------------------------------------
 
-    def transpose(self, *axes) -> ExtensionArray:
+    def transpose(self, *axes: int) -> ExtensionArray:
         """
         Return a transposed view on this array.
 
@@ -1220,7 +1227,7 @@ def transpose(self, *axes) -> ExtensionArray:
     def T(self) -> ExtensionArray:
         return self.transpose()
 
-    def ravel(self, order="C") -> ExtensionArray:
+    def ravel(self, order: Literal["C", "F", "A", "K"] | None = "C") -> ExtensionArray:
         """
         Return a flattened view on this array.
 
@@ -1294,7 +1301,7 @@ def _reduce(self, name: str, *, skipna: bool = True, **kwargs):
         """
         raise TypeError(f"cannot perform {name} with type {self.dtype}")
 
-    def __hash__(self):
+    def __hash__(self) -> int:
         raise TypeError(f"unhashable type: {repr(type(self).__name__)}")
 
     # ------------------------------------------------------------------------

From ca0ba554853b7674d90474ed5137324807f61c89 Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Sat, 1 May 2021 20:02:45 -0400
Subject: [PATCH 2/9] fix fillna value default arg

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

diff --git a/pandas/core/arrays/base.py b/pandas/core/arrays/base.py
index 62f148a68857d..5e7cf2bb05b9a 100644
--- a/pandas/core/arrays/base.py
+++ b/pandas/core/arrays/base.py
@@ -684,7 +684,7 @@ def argmax(self, skipna: bool = True) -> int:
 
     def fillna(
         self,
-        value: Any | ArrayLike | None,
+        value: Any | ArrayLike | None = None,
         method: Literal["backfill", "bfill", "ffill", "pad"] | None = None,
         limit: int | None = None,
     ):

From 7e46ad29a5d6c2aac9a5e2cd301d9bc22a5097b6 Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Sun, 2 May 2021 10:08:02 -0400
Subject: [PATCH 3/9] specify args for transpose

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

diff --git a/pandas/core/arrays/base.py b/pandas/core/arrays/base.py
index 5e7cf2bb05b9a..abbb85d5ade3f 100644
--- a/pandas/core/arrays/base.py
+++ b/pandas/core/arrays/base.py
@@ -1214,7 +1214,7 @@ def _formatter(self, boxed: bool = False) -> Callable[[Any], str | None]:
     # Reshaping
     # ------------------------------------------------------------------------
 
-    def transpose(self, *axes: int) -> ExtensionArray:
+    def transpose(self, *axes: tuple[int] | list[int] | None) -> ExtensionArray:
         """
         Return a transposed view on this array.
 

From 30b6dcb9d42cebf31f807541b27fcf5ebd86284c Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Sun, 2 May 2021 19:51:50 -0400
Subject: [PATCH 4/9] update transpose and fillna to use consistent typing

---
 pandas/_typing.py          |  1 +
 pandas/core/arrays/base.py |  3 ++-
 pandas/core/base.py        |  5 +++--
 pandas/core/frame.py       | 23 ++++++++++++-----------
 pandas/core/series.py      | 16 ++++++++--------
 5 files changed, 26 insertions(+), 22 deletions(-)

diff --git a/pandas/_typing.py b/pandas/_typing.py
index a58dc0dba1bf1..08e462e8db237 100644
--- a/pandas/_typing.py
+++ b/pandas/_typing.py
@@ -112,6 +112,7 @@
 FrameOrSeries = TypeVar("FrameOrSeries", bound="NDFrame")
 
 Axis = Union[str, int]
+NumpyAxis = Union[Tuple[int], List[int], None]
 IndexLabel = Union[Hashable, Sequence[Hashable]]
 Level = Union[Hashable, int]
 Shape = Tuple[int, ...]
diff --git a/pandas/core/arrays/base.py b/pandas/core/arrays/base.py
index abbb85d5ade3f..65d9edc523059 100644
--- a/pandas/core/arrays/base.py
+++ b/pandas/core/arrays/base.py
@@ -25,6 +25,7 @@
 from pandas._typing import (
     ArrayLike,
     Dtype,
+    NumpyAxis,
     PositionalIndexer,
     Shape,
 )
@@ -1214,7 +1215,7 @@ def _formatter(self, boxed: bool = False) -> Callable[[Any], str | None]:
     # Reshaping
     # ------------------------------------------------------------------------
 
-    def transpose(self, *axes: tuple[int] | list[int] | None) -> ExtensionArray:
+    def transpose(self, axes: NumpyAxis = None) -> ExtensionArray:
         """
         Return a transposed view on this array.
 
diff --git a/pandas/core/base.py b/pandas/core/base.py
index 42f52618eb07b..5f6a2c25cab6c 100644
--- a/pandas/core/base.py
+++ b/pandas/core/base.py
@@ -19,6 +19,7 @@
     Dtype,
     DtypeObj,
     IndexLabel,
+    NumpyAxis,
     Shape,
     final,
 )
@@ -298,7 +299,7 @@ def _values(self) -> ExtensionArray | np.ndarray:
         # must be defined here as a property for mypy
         raise AbstractMethodError(self)
 
-    def transpose(self: _T, *args, **kwargs) -> _T:
+    def transpose(self: _T, axes: NumpyAxis = None) -> _T:
         """
         Return the transpose, which is by definition self.
 
@@ -306,7 +307,7 @@ def transpose(self: _T, *args, **kwargs) -> _T:
         -------
         %(klass)s
         """
-        nv.validate_transpose(args, kwargs)
+        nv.validate_transpose(axes, {})
         return self
 
     T = property(
diff --git a/pandas/core/frame.py b/pandas/core/frame.py
index 4469869a5a929..1cc6a2f38d5c1 100644
--- a/pandas/core/frame.py
+++ b/pandas/core/frame.py
@@ -62,6 +62,7 @@
     IndexLabel,
     Level,
     NpDtype,
+    NumpyAxis,
     PythonFuncType,
     Renamer,
     Scalar,
@@ -3189,7 +3190,7 @@ def memory_usage(self, index: bool = True, deep: bool = False) -> Series:
             ).append(result)
         return result
 
-    def transpose(self, *args, copy: bool = False) -> DataFrame:
+    def transpose(self, axes: NumpyAxis = None, copy: bool = False) -> DataFrame:
         """
         Transpose index and columns.
 
@@ -3199,7 +3200,7 @@ def transpose(self, *args, copy: bool = False) -> DataFrame:
 
         Parameters
         ----------
-        *args : tuple, optional
+        axes : tuple or list, optional
             Accepted for compatibility with NumPy.
         copy : bool, default False
             Whether to copy the data after transposing, even for DataFrames
@@ -3286,7 +3287,7 @@ def transpose(self, *args, copy: bool = False) -> DataFrame:
         1    object
         dtype: object
         """
-        nv.validate_transpose(args, {})
+        nv.validate_transpose(axes, {})
         # construct the args
 
         dtypes = list(self.dtypes)
@@ -5015,7 +5016,7 @@ def rename(
     def fillna(
         self,
         value=...,
-        method: str | None = ...,
+        method: Literal["backfill", "bfill", "ffill", "pad"] | None = ...,
         axis: Axis | None = ...,
         inplace: Literal[False] = ...,
         limit=...,
@@ -5027,7 +5028,7 @@ def fillna(
     def fillna(
         self,
         value,
-        method: str | None,
+        method: Literal["backfill", "bfill", "ffill", "pad"] | None,
         axis: Axis | None,
         inplace: Literal[True],
         limit=...,
@@ -5060,7 +5061,7 @@ def fillna(
     def fillna(
         self,
         *,
-        method: str | None,
+        method: Literal["backfill", "bfill", "ffill", "pad"] | None,
         inplace: Literal[True],
         limit=...,
         downcast=...,
@@ -5082,7 +5083,7 @@ def fillna(
     def fillna(
         self,
         *,
-        method: str | None,
+        method: Literal["backfill", "bfill", "ffill", "pad"] | None,
         axis: Axis | None,
         inplace: Literal[True],
         limit=...,
@@ -5106,7 +5107,7 @@ def fillna(
     def fillna(
         self,
         value,
-        method: str | None,
+        method: Literal["backfill", "bfill", "ffill", "pad"] | None,
         *,
         inplace: Literal[True],
         limit=...,
@@ -5118,7 +5119,7 @@ def fillna(
     def fillna(
         self,
         value=...,
-        method: str | None = ...,
+        method: Literal["backfill", "bfill", "ffill", "pad"] | None = ...,
         axis: Axis | None = ...,
         inplace: bool = ...,
         limit=...,
@@ -5129,8 +5130,8 @@ def fillna(
     @doc(NDFrame.fillna, **_shared_doc_kwargs)
     def fillna(
         self,
-        value=None,
-        method: str | None = None,
+        value: Any | ArrayLike | None = None,
+        method: Literal["backfill", "bfill", "ffill", "pad"] | None = None,
         axis: Axis | None = None,
         inplace: bool = False,
         limit=None,
diff --git a/pandas/core/series.py b/pandas/core/series.py
index 6a3e997a58754..bf73f7a116609 100644
--- a/pandas/core/series.py
+++ b/pandas/core/series.py
@@ -4594,7 +4594,7 @@ def drop(
     def fillna(
         self,
         value=...,
-        method: str | None = ...,
+        method: Literal["backfill", "bfill", "ffill", "pad"] | None = ...,
         axis: Axis | None = ...,
         inplace: Literal[False] = ...,
         limit=...,
@@ -4606,7 +4606,7 @@ def fillna(
     def fillna(
         self,
         value,
-        method: str | None,
+        method: Literal["backfill", "bfill", "ffill", "pad"] | None,
         axis: Axis | None,
         inplace: Literal[True],
         limit=...,
@@ -4639,7 +4639,7 @@ def fillna(
     def fillna(
         self,
         *,
-        method: str | None,
+        method: Literal["backfill", "bfill", "ffill", "pad"] | None,
         inplace: Literal[True],
         limit=...,
         downcast=...,
@@ -4661,7 +4661,7 @@ def fillna(
     def fillna(
         self,
         *,
-        method: str | None,
+        method: Literal["backfill", "bfill", "ffill", "pad"] | None,
         axis: Axis | None,
         inplace: Literal[True],
         limit=...,
@@ -4685,7 +4685,7 @@ def fillna(
     def fillna(
         self,
         value,
-        method: str | None,
+        method: Literal["backfill", "bfill", "ffill", "pad"] | None,
         *,
         inplace: Literal[True],
         limit=...,
@@ -4697,7 +4697,7 @@ def fillna(
     def fillna(
         self,
         value=...,
-        method: str | None = ...,
+        method: Literal["backfill", "bfill", "ffill", "pad"] | None = ...,
         axis: Axis | None = ...,
         inplace: bool = ...,
         limit=...,
@@ -4709,8 +4709,8 @@ def fillna(
     @doc(NDFrame.fillna, **_shared_doc_kwargs)  # type: ignore[has-type]
     def fillna(
         self,
-        value=None,
-        method=None,
+        value: Any | ArrayLike | None = None,
+        method: Literal["backfill", "bfill", "ffill", "pad"] | None = None,
         axis=None,
         inplace=False,
         limit=None,

From ee12178704f741725b839d0c76571781e87f314b Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Sun, 2 May 2021 21:24:20 -0400
Subject: [PATCH 5/9] undo change to transpose in core/base.py

---
 pandas/core/base.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/pandas/core/base.py b/pandas/core/base.py
index 5f6a2c25cab6c..42f52618eb07b 100644
--- a/pandas/core/base.py
+++ b/pandas/core/base.py
@@ -19,7 +19,6 @@
     Dtype,
     DtypeObj,
     IndexLabel,
-    NumpyAxis,
     Shape,
     final,
 )
@@ -299,7 +298,7 @@ def _values(self) -> ExtensionArray | np.ndarray:
         # must be defined here as a property for mypy
         raise AbstractMethodError(self)
 
-    def transpose(self: _T, axes: NumpyAxis = None) -> _T:
+    def transpose(self: _T, *args, **kwargs) -> _T:
         """
         Return the transpose, which is by definition self.
 
@@ -307,7 +306,7 @@ def transpose(self: _T, axes: NumpyAxis = None) -> _T:
         -------
         %(klass)s
         """
-        nv.validate_transpose(axes, {})
+        nv.validate_transpose(args, kwargs)
         return self
 
     T = property(

From 4b9bd1ec210e82de69cdae1cd2573e6c9f694d61 Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Sun, 2 May 2021 22:34:35 -0400
Subject: [PATCH 6/9] fix transpose to use axes argument

---
 pandas/core/base.py                  | 7 +++++--
 pandas/tests/generic/test_generic.py | 2 +-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/pandas/core/base.py b/pandas/core/base.py
index 42f52618eb07b..57199ca151b20 100644
--- a/pandas/core/base.py
+++ b/pandas/core/base.py
@@ -19,6 +19,7 @@
     Dtype,
     DtypeObj,
     IndexLabel,
+    NumpyAxis,
     Shape,
     final,
 )
@@ -298,7 +299,7 @@ def _values(self) -> ExtensionArray | np.ndarray:
         # must be defined here as a property for mypy
         raise AbstractMethodError(self)
 
-    def transpose(self: _T, *args, **kwargs) -> _T:
+    def transpose(self: _T, axes: NumpyAxis = None) -> _T:
         """
         Return the transpose, which is by definition self.
 
@@ -306,7 +307,9 @@ def transpose(self: _T, *args, **kwargs) -> _T:
         -------
         %(klass)s
         """
-        nv.validate_transpose(args, kwargs)
+        if not (isinstance(axes, list) and isinstance(axes, tuple)):
+            axes = (axes,)
+        nv.validate_transpose(axes, {})
         return self
 
     T = property(
diff --git a/pandas/tests/generic/test_generic.py b/pandas/tests/generic/test_generic.py
index d07f843f4acfc..565be920a3b6a 100644
--- a/pandas/tests/generic/test_generic.py
+++ b/pandas/tests/generic/test_generic.py
@@ -405,7 +405,7 @@ def test_numpy_transpose(self, frame_or_series):
         # round-trip preserved
         tm.assert_equal(np.transpose(np.transpose(obj)), obj)
 
-        msg = "the 'axes' parameter is not supported"
+        msg = r"(the 'axes' parameter is not supported|axes don't match array)"
         with pytest.raises(ValueError, match=msg):
             np.transpose(obj, axes=1)
 

From 488a3dea6afb7280aa5ff0fe9063e27bce7de6f6 Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Mon, 3 May 2021 06:38:52 -0400
Subject: [PATCH 7/9] typing fix in pandas/core/base.py

---
 pandas/core/base.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/pandas/core/base.py b/pandas/core/base.py
index 57199ca151b20..1091c09fdb1b1 100644
--- a/pandas/core/base.py
+++ b/pandas/core/base.py
@@ -308,8 +308,10 @@ def transpose(self: _T, axes: NumpyAxis = None) -> _T:
         %(klass)s
         """
         if not (isinstance(axes, list) and isinstance(axes, tuple)):
-            axes = (axes,)
-        nv.validate_transpose(axes, {})
+            args = (axes,)
+        else:
+            args = axes
+        nv.validate_transpose(args, {})
         return self
 
     T = property(

From 5ccb62ab201bc6fa7b5e8dadd363ead6e43ff4e9 Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Tue, 4 May 2021 07:44:04 -0400
Subject: [PATCH 8/9] undo transpose changes.  Use object for fillna and
 __contains__

---
 pandas/_typing.py                    |  1 -
 pandas/core/arrays/base.py           | 11 ++++++-----
 pandas/core/base.py                  |  9 ++-------
 pandas/core/frame.py                 |  9 ++++-----
 pandas/core/series.py                |  2 +-
 pandas/tests/generic/test_generic.py |  2 +-
 6 files changed, 14 insertions(+), 20 deletions(-)

diff --git a/pandas/_typing.py b/pandas/_typing.py
index 08e462e8db237..a58dc0dba1bf1 100644
--- a/pandas/_typing.py
+++ b/pandas/_typing.py
@@ -112,7 +112,6 @@
 FrameOrSeries = TypeVar("FrameOrSeries", bound="NDFrame")
 
 Axis = Union[str, int]
-NumpyAxis = Union[Tuple[int], List[int], None]
 IndexLabel = Union[Hashable, Sequence[Hashable]]
 Level = Union[Hashable, int]
 Shape = Tuple[int, ...]
diff --git a/pandas/core/arrays/base.py b/pandas/core/arrays/base.py
index 7214cdd4ec8ae..5710775f6c89a 100644
--- a/pandas/core/arrays/base.py
+++ b/pandas/core/arrays/base.py
@@ -25,7 +25,6 @@
 from pandas._typing import (
     ArrayLike,
     Dtype,
-    NumpyAxis,
     PositionalIndexer,
     Shape,
 )
@@ -388,7 +387,7 @@ def __iter__(self) -> Iterator[Any]:
         for i in range(len(self)):
             yield self[i]
 
-    def __contains__(self, item: Any) -> bool | np.bool_:
+    def __contains__(self, item: object) -> bool | np.bool_:
         """
         Return for `item in self`.
         """
@@ -403,7 +402,9 @@ def __contains__(self, item: Any) -> bool | np.bool_:
             else:
                 return False
         else:
-            return (item == self).any()
+            # error: Item "ExtensionArray" of "Union[ExtensionArray, ndarray]" has no
+            # attribute "any"
+            return (item == self).any()  # type: ignore[union-attr]
 
     # error: Signature of "__eq__" incompatible with supertype "object"
     def __eq__(self, other: Any) -> ArrayLike:  # type: ignore[override]
@@ -685,7 +686,7 @@ def argmax(self, skipna: bool = True) -> int:
 
     def fillna(
         self,
-        value: Any | ArrayLike | None = None,
+        value: object | ArrayLike | None = None,
         method: Literal["backfill", "bfill", "ffill", "pad"] | None = None,
         limit: int | None = None,
     ):
@@ -1215,7 +1216,7 @@ def _formatter(self, boxed: bool = False) -> Callable[[Any], str | None]:
     # Reshaping
     # ------------------------------------------------------------------------
 
-    def transpose(self, axes: NumpyAxis = None) -> ExtensionArray:
+    def transpose(self, *axes: int) -> ExtensionArray:
         """
         Return a transposed view on this array.
 
diff --git a/pandas/core/base.py b/pandas/core/base.py
index ccdb88a8a5f8b..3270e3dd82f7d 100644
--- a/pandas/core/base.py
+++ b/pandas/core/base.py
@@ -20,7 +20,6 @@
     Dtype,
     DtypeObj,
     IndexLabel,
-    NumpyAxis,
     Shape,
     final,
 )
@@ -300,7 +299,7 @@ def _values(self) -> ExtensionArray | np.ndarray:
         # must be defined here as a property for mypy
         raise AbstractMethodError(self)
 
-    def transpose(self: _T, axes: NumpyAxis = None) -> _T:
+    def transpose(self: _T, *args, **kwargs) -> _T:
         """
         Return the transpose, which is by definition self.
 
@@ -308,11 +307,7 @@ def transpose(self: _T, axes: NumpyAxis = None) -> _T:
         -------
         %(klass)s
         """
-        if not (isinstance(axes, list) and isinstance(axes, tuple)):
-            args = (axes,)
-        else:
-            args = axes
-        nv.validate_transpose(args, {})
+        nv.validate_transpose(args, kwargs)
         return self
 
     T = property(
diff --git a/pandas/core/frame.py b/pandas/core/frame.py
index fc9920c5af404..052a7de5ed092 100644
--- a/pandas/core/frame.py
+++ b/pandas/core/frame.py
@@ -62,7 +62,6 @@
     IndexLabel,
     Level,
     NpDtype,
-    NumpyAxis,
     PythonFuncType,
     Renamer,
     Scalar,
@@ -3190,7 +3189,7 @@ def memory_usage(self, index: bool = True, deep: bool = False) -> Series:
             ).append(result)
         return result
 
-    def transpose(self, axes: NumpyAxis = None, copy: bool = False) -> DataFrame:
+    def transpose(self, *args, copy: bool = False) -> DataFrame:
         """
         Transpose index and columns.
 
@@ -3200,7 +3199,7 @@ def transpose(self, axes: NumpyAxis = None, copy: bool = False) -> DataFrame:
 
         Parameters
         ----------
-        axes : tuple or list, optional
+        *args : tuple, optional
             Accepted for compatibility with NumPy.
         copy : bool, default False
             Whether to copy the data after transposing, even for DataFrames
@@ -3287,7 +3286,7 @@ def transpose(self, axes: NumpyAxis = None, copy: bool = False) -> DataFrame:
         1    object
         dtype: object
         """
-        nv.validate_transpose(axes, {})
+        nv.validate_transpose(args, {})
         # construct the args
 
         dtypes = list(self.dtypes)
@@ -5130,7 +5129,7 @@ def fillna(
     @doc(NDFrame.fillna, **_shared_doc_kwargs)
     def fillna(
         self,
-        value: Any | ArrayLike | None = None,
+        value: object | ArrayLike | None = None,
         method: Literal["backfill", "bfill", "ffill", "pad"] | None = None,
         axis: Axis | None = None,
         inplace: bool = False,
diff --git a/pandas/core/series.py b/pandas/core/series.py
index ee46e86b610f3..dbf55ab7e2d0d 100644
--- a/pandas/core/series.py
+++ b/pandas/core/series.py
@@ -4709,7 +4709,7 @@ def fillna(
     @doc(NDFrame.fillna, **_shared_doc_kwargs)  # type: ignore[has-type]
     def fillna(
         self,
-        value: Any | ArrayLike | None = None,
+        value: object | ArrayLike | None = None,
         method: Literal["backfill", "bfill", "ffill", "pad"] | None = None,
         axis=None,
         inplace=False,
diff --git a/pandas/tests/generic/test_generic.py b/pandas/tests/generic/test_generic.py
index 565be920a3b6a..d07f843f4acfc 100644
--- a/pandas/tests/generic/test_generic.py
+++ b/pandas/tests/generic/test_generic.py
@@ -405,7 +405,7 @@ def test_numpy_transpose(self, frame_or_series):
         # round-trip preserved
         tm.assert_equal(np.transpose(np.transpose(obj)), obj)
 
-        msg = r"(the 'axes' parameter is not supported|axes don't match array)"
+        msg = "the 'axes' parameter is not supported"
         with pytest.raises(ValueError, match=msg):
             np.transpose(obj, axes=1)
 

From c216bd911417a127a00a3e069850a1e4d9855a9e Mon Sep 17 00:00:00 2001
From: Irv Lustig <irv@princeton.com>
Date: Wed, 5 May 2021 11:15:46 -0400
Subject: [PATCH 9/9] create type for fillna arguments

---
 pandas/_typing.py          |  7 +++++++
 pandas/core/arrays/base.py |  3 ++-
 pandas/core/frame.py       | 15 ++++++++-------
 pandas/core/series.py      | 15 ++++++++-------
 4 files changed, 25 insertions(+), 15 deletions(-)

diff --git a/pandas/_typing.py b/pandas/_typing.py
index a58dc0dba1bf1..1e1fffdd60676 100644
--- a/pandas/_typing.py
+++ b/pandas/_typing.py
@@ -37,6 +37,7 @@
 # https://mypy.readthedocs.io/en/latest/common_issues.html#import-cycles
 if TYPE_CHECKING:
     from typing import (
+        Literal,
         TypedDict,
         final,
     )
@@ -189,6 +190,12 @@
     str, int, Sequence[Union[str, int]], Mapping[Hashable, Union[str, int]]
 ]
 
+# Arguments for fillna()
+if TYPE_CHECKING:
+    FillnaOptions = Literal["backfill", "bfill", "ffill", "pad"]
+else:
+    FillnaOptions = str
+
 # internals
 Manager = Union[
     "ArrayManager", "SingleArrayManager", "BlockManager", "SingleBlockManager"
diff --git a/pandas/core/arrays/base.py b/pandas/core/arrays/base.py
index 5710775f6c89a..16d42e4a51927 100644
--- a/pandas/core/arrays/base.py
+++ b/pandas/core/arrays/base.py
@@ -25,6 +25,7 @@
 from pandas._typing import (
     ArrayLike,
     Dtype,
+    FillnaOptions,
     PositionalIndexer,
     Shape,
 )
@@ -687,7 +688,7 @@ def argmax(self, skipna: bool = True) -> int:
     def fillna(
         self,
         value: object | ArrayLike | None = None,
-        method: Literal["backfill", "bfill", "ffill", "pad"] | None = None,
+        method: FillnaOptions | None = None,
         limit: int | None = None,
     ):
         """
diff --git a/pandas/core/frame.py b/pandas/core/frame.py
index d36d6c04e94e6..a508b3db2f038 100644
--- a/pandas/core/frame.py
+++ b/pandas/core/frame.py
@@ -54,6 +54,7 @@
     CompressionOptions,
     Dtype,
     FilePathOrBuffer,
+    FillnaOptions,
     FloatFormatType,
     FormattersType,
     FrameOrSeriesUnion,
@@ -5015,7 +5016,7 @@ def rename(
     def fillna(
         self,
         value=...,
-        method: Literal["backfill", "bfill", "ffill", "pad"] | None = ...,
+        method: FillnaOptions | None = ...,
         axis: Axis | None = ...,
         inplace: Literal[False] = ...,
         limit=...,
@@ -5027,7 +5028,7 @@ def fillna(
     def fillna(
         self,
         value,
-        method: Literal["backfill", "bfill", "ffill", "pad"] | None,
+        method: FillnaOptions | None,
         axis: Axis | None,
         inplace: Literal[True],
         limit=...,
@@ -5060,7 +5061,7 @@ def fillna(
     def fillna(
         self,
         *,
-        method: Literal["backfill", "bfill", "ffill", "pad"] | None,
+        method: FillnaOptions | None,
         inplace: Literal[True],
         limit=...,
         downcast=...,
@@ -5082,7 +5083,7 @@ def fillna(
     def fillna(
         self,
         *,
-        method: Literal["backfill", "bfill", "ffill", "pad"] | None,
+        method: FillnaOptions | None,
         axis: Axis | None,
         inplace: Literal[True],
         limit=...,
@@ -5106,7 +5107,7 @@ def fillna(
     def fillna(
         self,
         value,
-        method: Literal["backfill", "bfill", "ffill", "pad"] | None,
+        method: FillnaOptions | None,
         *,
         inplace: Literal[True],
         limit=...,
@@ -5118,7 +5119,7 @@ def fillna(
     def fillna(
         self,
         value=...,
-        method: Literal["backfill", "bfill", "ffill", "pad"] | None = ...,
+        method: FillnaOptions | None = ...,
         axis: Axis | None = ...,
         inplace: bool = ...,
         limit=...,
@@ -5130,7 +5131,7 @@ def fillna(
     def fillna(
         self,
         value: object | ArrayLike | None = None,
-        method: Literal["backfill", "bfill", "ffill", "pad"] | None = None,
+        method: FillnaOptions | None = None,
         axis: Axis | None = None,
         inplace: bool = False,
         limit=None,
diff --git a/pandas/core/series.py b/pandas/core/series.py
index b1e57a909908e..c8e9898f9462a 100644
--- a/pandas/core/series.py
+++ b/pandas/core/series.py
@@ -38,6 +38,7 @@
     Axis,
     Dtype,
     DtypeObj,
+    FillnaOptions,
     FrameOrSeriesUnion,
     IndexKeyFunc,
     NpDtype,
@@ -4594,7 +4595,7 @@ def drop(
     def fillna(
         self,
         value=...,
-        method: Literal["backfill", "bfill", "ffill", "pad"] | None = ...,
+        method: FillnaOptions | None = ...,
         axis: Axis | None = ...,
         inplace: Literal[False] = ...,
         limit=...,
@@ -4606,7 +4607,7 @@ def fillna(
     def fillna(
         self,
         value,
-        method: Literal["backfill", "bfill", "ffill", "pad"] | None,
+        method: FillnaOptions | None,
         axis: Axis | None,
         inplace: Literal[True],
         limit=...,
@@ -4639,7 +4640,7 @@ def fillna(
     def fillna(
         self,
         *,
-        method: Literal["backfill", "bfill", "ffill", "pad"] | None,
+        method: FillnaOptions | None,
         inplace: Literal[True],
         limit=...,
         downcast=...,
@@ -4661,7 +4662,7 @@ def fillna(
     def fillna(
         self,
         *,
-        method: Literal["backfill", "bfill", "ffill", "pad"] | None,
+        method: FillnaOptions | None,
         axis: Axis | None,
         inplace: Literal[True],
         limit=...,
@@ -4685,7 +4686,7 @@ def fillna(
     def fillna(
         self,
         value,
-        method: Literal["backfill", "bfill", "ffill", "pad"] | None,
+        method: FillnaOptions | None,
         *,
         inplace: Literal[True],
         limit=...,
@@ -4697,7 +4698,7 @@ def fillna(
     def fillna(
         self,
         value=...,
-        method: Literal["backfill", "bfill", "ffill", "pad"] | None = ...,
+        method: FillnaOptions | None = ...,
         axis: Axis | None = ...,
         inplace: bool = ...,
         limit=...,
@@ -4710,7 +4711,7 @@ def fillna(
     def fillna(
         self,
         value: object | ArrayLike | None = None,
-        method: Literal["backfill", "bfill", "ffill", "pad"] | None = None,
+        method: FillnaOptions | None = None,
         axis=None,
         inplace=False,
         limit=None,