type align (#1138)

* type align

* prefer Scalar | NAType | None

Author: MarcoGorelli

Diff for: 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: Scalar | NAType | None = ...,
     ) -> tuple[Self, NDFrameT]: ...
     def reindex(
         self,

Diff for: 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: Scalar | NAType | None = ...,
     ) -> tuple[Series, Series]: ...
     @overload
     def rename(

Diff for: 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 for: 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)