From c7192f655d8557143fa82cfff95cf3c57666e571 Mon Sep 17 00:00:00 2001
From: Marco Gorelli <33491632+MarcoGorelli@users.noreply.github.com>
Date: Sun, 2 Mar 2025 14:56:21 +0000
Subject: [PATCH 1/2] type align

---
 pandas-stubs/core/frame.pyi  |  6 +-----
 pandas-stubs/core/series.pyi |  6 +-----
 tests/test_frame.py          |  3 +++
 tests/test_series.py         | 11 +++++++++++
 4 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/pandas-stubs/core/frame.pyi b/pandas-stubs/core/frame.pyi
index 344dd3a39..0dcdb0047 100644
--- a/pandas-stubs/core/frame.pyi
+++ b/pandas-stubs/core/frame.pyi
@@ -732,11 +732,7 @@ class DataFrame(NDFrame, OpsMixin, _GetItemHack):
         axis: Axis | None = ...,
         level: Level | None = ...,
         copy: _bool = ...,
-        fill_value=...,
-        method: FillnaOptions | None = ...,
-        limit: int | None = ...,
-        fill_axis: Axis = ...,
-        broadcast_axis: Axis | None = ...,
+        fill_value: Hashable | None = ...,
     ) -> tuple[Self, NDFrameT]: ...
     def reindex(
         self,
diff --git a/pandas-stubs/core/series.pyi b/pandas-stubs/core/series.pyi
index 2ade583c7..bf090a5fa 100644
--- a/pandas-stubs/core/series.pyi
+++ b/pandas-stubs/core/series.pyi
@@ -1034,11 +1034,7 @@ class Series(IndexOpsMixin[S1], NDFrame):
         axis: Axis | None = ...,
         level: Level | None = ...,
         copy: _bool = ...,
-        fill_value=...,
-        method: FillnaOptions | None = ...,
-        limit: int | None = ...,
-        fill_axis: AxisIndex = ...,
-        broadcast_axis: AxisIndex | None = ...,
+        fill_value: Hashable | None = ...,
     ) -> tuple[Series, Series]: ...
     @overload
     def rename(
diff --git a/tests/test_frame.py b/tests/test_frame.py
index e506528e3..c97fa47cf 100644
--- a/tests/test_frame.py
+++ b/tests/test_frame.py
@@ -3662,6 +3662,9 @@ def test_align() -> None:
     aligned_df0, aligned_s0 = df0.align(s0, axis="index")
     check(assert_type(aligned_df0, pd.DataFrame), pd.DataFrame)
     check(assert_type(aligned_s0, "pd.Series[str]"), pd.Series, str)
+    aligned_df0, aligned_s0 = df0.align(s0, axis="index", fill_value=0)
+    check(assert_type(aligned_df0, pd.DataFrame), pd.DataFrame)
+    check(assert_type(aligned_s0, "pd.Series[str]"), pd.Series, str)
 
     s1 = pd.Series(data={"A": "A", "D": "D"})
     aligned_df0, aligned_s1 = df0.align(s1, axis="columns")
diff --git a/tests/test_series.py b/tests/test_series.py
index 0c700fcbd..c76fc9856 100644
--- a/tests/test_series.py
+++ b/tests/test_series.py
@@ -3672,3 +3672,14 @@ def test_info() -> None:
     check(assert_type(s.info(show_counts=True), None), type(None))
     check(assert_type(s.info(show_counts=False), None), type(None))
     check(assert_type(s.info(show_counts=None), None), type(None))
+
+
+def test_align() -> None:
+    s0 = pd.Series(data={0: 1, 3: 3, 5: 5})
+    s1 = pd.Series(data={0: 1, 2: 2})
+    aligned_s0, aligned_s1 = s0.align(s1)
+    check(assert_type(aligned_s0, pd.Series), pd.Series)
+    check(assert_type(aligned_s1, pd.Series), pd.Series)
+    aligned_s0, aligned_s1 = s0.align(s1, fill_value=0, axis=0, level=0, copy=False)
+    check(assert_type(aligned_s0, pd.Series), pd.Series)
+    check(assert_type(aligned_s1, pd.Series), pd.Series)

From 768384a00127d10233380ffa7127d3a220df9a8d Mon Sep 17 00:00:00 2001
From: Marco Gorelli <33491632+MarcoGorelli@users.noreply.github.com>
Date: Tue, 4 Mar 2025 10:17:19 +0000
Subject: [PATCH 2/2] prefer Scalar | NAType | None

---
 pandas-stubs/core/frame.pyi  | 2 +-
 pandas-stubs/core/series.pyi | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/pandas-stubs/core/frame.pyi b/pandas-stubs/core/frame.pyi
index fafc78c99..4c4fb3d76 100644
--- a/pandas-stubs/core/frame.pyi
+++ b/pandas-stubs/core/frame.pyi
@@ -732,7 +732,7 @@ class DataFrame(NDFrame, OpsMixin, _GetItemHack):
         axis: Axis | None = ...,
         level: Level | None = ...,
         copy: _bool = ...,
-        fill_value: Hashable | None = ...,
+        fill_value: Scalar | NAType | None = ...,
     ) -> tuple[Self, NDFrameT]: ...
     def reindex(
         self,
diff --git a/pandas-stubs/core/series.pyi b/pandas-stubs/core/series.pyi
index 6014fc4f7..69779d5ef 100644
--- a/pandas-stubs/core/series.pyi
+++ b/pandas-stubs/core/series.pyi
@@ -1034,7 +1034,7 @@ class Series(IndexOpsMixin[S1], NDFrame):
         axis: Axis | None = ...,
         level: Level | None = ...,
         copy: _bool = ...,
-        fill_value: Hashable | None = ...,
+        fill_value: Scalar | NAType | None = ...,
     ) -> tuple[Series, Series]: ...
     @overload
     def rename(