Merge pull request numpy#27220 from jorenham/typing/chararray-typevar-cleanup

TYP: Fixed & improved ``TypeVar`` use for ``numpy.char.chararray``

Author: charris

numpy/__init__.pyi

@@ -4409,11 +4409,6 @@ class matrix(ndarray[_Shape2DType_co, _DType_co]):
     def getA1(self) -> ndarray[_Shape, _DType_co]: ...
     def getH(self) -> matrix[_Shape2D, _DType_co]: ...
 
-_CharType = TypeVar("_CharType", str_, bytes_)
-_CharDType = TypeVar("_CharDType", dtype[str_], dtype[bytes_])
-
-# NOTE: Deprecated
-# class MachAr: ...
 
 class _SupportsDLPack(Protocol[_T_contra]):
     def __dlpack__(self, *, stream: None | _T_contra = ...) -> _PyCapsule: ...

numpy/_core/defchararray.pyi

@@ -1,6 +1,7 @@
 from typing import (
     Literal as L,
     overload,
+    TypeAlias,
     TypeVar,
     Any,
     SupportsIndex,
@@ -17,7 +18,6 @@ from numpy import (
     object_,
     _OrderKACF,
     _ShapeType_co,
-    _CharDType,
     _SupportsBuffer,
 )
 
@@ -33,10 +33,15 @@ from numpy._typing import (
 
 from numpy._core.multiarray import compare_chararrays as compare_chararrays
 
-_SCT = TypeVar("_SCT", str_, bytes_)
-_CharArray = chararray[_Shape, dtype[_SCT]]
+_SCT = TypeVar("_SCT", bound=str_ | bytes_)
+_CharDType_co = TypeVar(
+    "_CharDType_co",
+    bound=dtype[str_ | bytes_],
+    covariant=True,
+)
+_CharArray: TypeAlias = chararray[tuple[int, ...], dtype[_SCT]]
 
-class chararray(ndarray[_ShapeType_co, _CharDType]):
+class chararray(ndarray[_ShapeType_co, _CharDType_co]):
     @overload
     def __new__(
         subtype,
@@ -61,9 +66,9 @@ class chararray(ndarray[_ShapeType_co, _CharDType]):
     ) -> chararray[_Shape, dtype[str_]]: ...
 
     def __array_finalize__(self, obj: object) -> None: ...
-    def __mul__(self, other: i_co) -> chararray[_Shape, _CharDType]: ...
-    def __rmul__(self, other: i_co) -> chararray[_Shape, _CharDType]: ...
-    def __mod__(self, i: Any) -> chararray[_Shape, _CharDType]: ...
+    def __mul__(self, other: i_co) -> chararray[_Shape, _CharDType_co]: ...
+    def __rmul__(self, other: i_co) -> chararray[_Shape, _CharDType_co]: ...
+    def __mod__(self, i: Any) -> chararray[_Shape, _CharDType_co]: ...
 
     @overload
     def __eq__(
@@ -211,7 +216,7 @@ class chararray(ndarray[_ShapeType_co, _CharDType]):
     def expandtabs(
         self,
         tabsize: i_co = ...,
-    ) -> chararray[_Shape, _CharDType]: ...
+    ) -> chararray[_Shape, _CharDType_co]: ...
 
     @overload
     def find(
@@ -436,12 +441,12 @@ class chararray(ndarray[_ShapeType_co, _CharDType]):
         deletechars: None | S_co = ...,
     ) -> _CharArray[bytes_]: ...
 
-    def zfill(self, width: _ArrayLikeInt_co) -> chararray[_Shape, _CharDType]: ...
-    def capitalize(self) -> chararray[_ShapeType_co, _CharDType]: ...
-    def title(self) -> chararray[_ShapeType_co, _CharDType]: ...
-    def swapcase(self) -> chararray[_ShapeType_co, _CharDType]: ...
-    def lower(self) -> chararray[_ShapeType_co, _CharDType]: ...
-    def upper(self) -> chararray[_ShapeType_co, _CharDType]: ...
+    def zfill(self, width: _ArrayLikeInt_co) -> chararray[_Shape, _CharDType_co]: ...
+    def capitalize(self) -> chararray[_ShapeType_co, _CharDType_co]: ...
+    def title(self) -> chararray[_ShapeType_co, _CharDType_co]: ...
+    def swapcase(self) -> chararray[_ShapeType_co, _CharDType_co]: ...
+    def lower(self) -> chararray[_ShapeType_co, _CharDType_co]: ...
+    def upper(self) -> chararray[_ShapeType_co, _CharDType_co]: ...
     def isalnum(self) -> ndarray[_ShapeType_co, dtype[np.bool]]: ...
     def isalpha(self) -> ndarray[_ShapeType_co, dtype[np.bool]]: ...
     def isdigit(self) -> ndarray[_ShapeType_co, dtype[np.bool]]: ...