STY: Replace `Union` with the `|` operator

22 files changed, 159 insertions, 178 deletions

diff --git a/numpy/__init__.pyi b/numpy/__init__.pyi
index 4c3e34072..039b9dfa7 100644
--- a/numpy/__init__.pyi
+++ b/numpy/__init__.pyi
@@ -949,11 +949,11 @@ class flatiter(Generic[_NdArraySubClass]):
     @overload
     def __getitem__(
         self: flatiter[ndarray[Any, dtype[_ScalarType]]],
-        key: Union[int, integer],
+        key: int | integer,
     ) -> _ScalarType: ...
     @overload
     def __getitem__(
-        self, key: Union[_ArrayLikeInt, slice, ellipsis],
+        self, key: _ArrayLikeInt | slice | ellipsis
     ) -> _NdArraySubClass: ...
     @overload
     def __array__(self: flatiter[ndarray[Any, _DType]], dtype: None = ..., /) -> ndarray[Any, _DType]: ...
@@ -1121,7 +1121,7 @@ class _ArrayOrScalarCommon:
         self,
         axis: None | SupportsIndex = ...,
         kind: None | _SortKind = ...,
-        order: Union[None, str, Sequence[str]] = ...,
+        order: None | str | Sequence[str] = ...,
     ) -> ndarray: ...
 
     @overload
@@ -1519,20 +1519,20 @@ class ndarray(_ArrayOrScalarCommon, Generic[_ShapeType, _DType_co]):
     ) -> ndarray[_ShapeType2, _DType]: ...
 
     @overload
-    def __getitem__(self, key: Union[
-        SupportsIndex,
-        _ArrayLikeInt_co,
-        Tuple[SupportsIndex | _ArrayLikeInt_co, ...],
-    ]) -> Any: ...
+    def __getitem__(self, key: (
+        SupportsIndex
+        | _ArrayLikeInt_co
+        | Tuple[SupportsIndex | _ArrayLikeInt_co, ...]
+    )) -> Any: ...
     @overload
-    def __getitem__(self, key: Union[
-        None,
-        slice,
-        ellipsis,
-        SupportsIndex,
-        _ArrayLikeInt_co,
-        Tuple[None | slice | ellipsis | _ArrayLikeInt_co | SupportsIndex, ...],
-    ]) -> ndarray[Any, _DType_co]: ...
+    def __getitem__(self, key: (
+        None
+        | slice
+        | ellipsis
+        | SupportsIndex
+        | _ArrayLikeInt_co
+        | Tuple[None | slice | ellipsis | _ArrayLikeInt_co | SupportsIndex, ...]
+    )) -> ndarray[Any, _DType_co]: ...
     @overload
     def __getitem__(self: NDArray[void], key: str) -> NDArray[Any]: ...
     @overload
@@ -1582,7 +1582,7 @@ class ndarray(_ArrayOrScalarCommon, Generic[_ShapeType, _DType_co]):
 
     def squeeze(
         self,
-        axis: Union[SupportsIndex, Tuple[SupportsIndex, ...]] = ...,
+        axis: SupportsIndex | Tuple[SupportsIndex, ...] = ...,
     ) -> ndarray[Any, _DType_co]: ...
 
     def swapaxes(
@@ -1601,7 +1601,7 @@ class ndarray(_ArrayOrScalarCommon, Generic[_ShapeType, _DType_co]):
         kth: _ArrayLikeInt_co,
         axis: None | SupportsIndex = ...,
         kind: _PartitionKind = ...,
-        order: Union[None, str, Sequence[str]] = ...,
+        order: None | str | Sequence[str] = ...,
     ) -> ndarray[Any, _dtype[intp]]: ...
 
     def diagonal(
@@ -1628,7 +1628,7 @@ class ndarray(_ArrayOrScalarCommon, Generic[_ShapeType, _DType_co]):
         kth: _ArrayLikeInt_co,
         axis: SupportsIndex = ...,
         kind: _PartitionKind = ...,
-        order: Union[None, str, Sequence[str]] = ...,
+        order: None | str | Sequence[str] = ...,
     ) -> None: ...
 
     # `put` is technically available to `generic`,
@@ -1666,7 +1666,7 @@ class ndarray(_ArrayOrScalarCommon, Generic[_ShapeType, _DType_co]):
         self,
         axis: SupportsIndex = ...,
         kind: None | _SortKind = ...,
-        order: Union[None, str, Sequence[str]] = ...,
+        order: None | str | Sequence[str] = ...,
     ) -> None: ...
 
     @overload
@@ -2592,7 +2592,7 @@ class generic(_ArrayOrScalarCommon):
     ) -> ndarray[Any, _dtype[_ScalarType]]: ...
 
     def squeeze(
-        self: _ScalarType, axis: Union[L[0], Tuple[()]] = ...
+        self: _ScalarType, axis: L[0] | Tuple[()] = ...
     ) -> _ScalarType: ...
     def transpose(self: _ScalarType, axes: Tuple[()] = ..., /) -> _ScalarType: ...
     # Keep `dtype` at the bottom to avoid name conflicts with `np.dtype`
@@ -3272,7 +3272,7 @@ class AxisError(ValueError, IndexError):
     @overload
     def __init__(self, axis: int, ndim: int, msg_prefix: None | str = ...) -> None: ...
 
-_CallType = TypeVar("_CallType", bound=Union[_ErrFunc, _SupportsWrite[str]])
+_CallType = TypeVar("_CallType", bound=_ErrFunc | _SupportsWrite[str])
 
 class errstate(Generic[_CallType], ContextDecorator):
     call: _CallType
@@ -3327,7 +3327,7 @@ class ndindex:
 class DataSource:
     def __init__(
         self,
-        destpath: Union[None, str, os.PathLike[str]] = ...,
+        destpath: None | str | os.PathLike[str] = ...,
     ) -> None: ...
     def __del__(self) -> None: ...
     def abspath(self, path: str) -> str: ...
@@ -3478,29 +3478,29 @@ class recarray(ndarray[_ShapeType, _DType_co]):
     def __getattribute__(self, attr: str) -> Any: ...
     def __setattr__(self, attr: str, val: ArrayLike) -> None: ...
     @overload
-    def __getitem__(self, indx: Union[
-        SupportsIndex,
-        _ArrayLikeInt_co,
-        Tuple[SupportsIndex | _ArrayLikeInt_co, ...],
-    ]) -> Any: ...
-    @overload
-    def __getitem__(self: recarray[Any, dtype[void]], indx: Union[
-        None,
-        slice,
-        ellipsis,
-        SupportsIndex,
-        _ArrayLikeInt_co,
-        Tuple[None | slice | ellipsis | _ArrayLikeInt_co | SupportsIndex, ...],
-    ]) -> recarray[Any, _DType_co]: ...
-    @overload
-    def __getitem__(self, indx: Union[
-        None,
-        slice,
-        ellipsis,
-        SupportsIndex,
-        _ArrayLikeInt_co,
-        Tuple[None | slice | ellipsis | _ArrayLikeInt_co | SupportsIndex, ...],
-    ]) -> ndarray[Any, _DType_co]: ...
+    def __getitem__(self, indx: (
+        SupportsIndex
+        | _ArrayLikeInt_co
+        | Tuple[SupportsIndex | _ArrayLikeInt_co, ...]
+    )) -> Any: ...
+    @overload
+    def __getitem__(self: recarray[Any, dtype[void]], indx: (
+        None
+        | slice
+        | ellipsis
+        | SupportsIndex
+        | _ArrayLikeInt_co
+        | Tuple[None | slice | ellipsis | _ArrayLikeInt_co | SupportsIndex, ...]
+    )) -> recarray[Any, _DType_co]: ...
+    @overload
+    def __getitem__(self, indx: (
+        None
+        | slice
+        | ellipsis
+        | SupportsIndex
+        | _ArrayLikeInt_co
+        | Tuple[None | slice | ellipsis | _ArrayLikeInt_co | SupportsIndex, ...]
+    )) -> ndarray[Any, _DType_co]: ...
     @overload
     def __getitem__(self, indx: str) -> NDArray[Any]: ...
     @overload
@@ -3781,20 +3781,20 @@ class matrix(ndarray[_ShapeType, _DType_co]):
     def __array_finalize__(self, obj: NDArray[Any]) -> None: ...
 
     @overload
-    def __getitem__(self, key: Union[
-        SupportsIndex,
-        _ArrayLikeInt_co,
-        Tuple[SupportsIndex | _ArrayLikeInt_co, ...],
-    ]) -> Any: ...
-    @overload
-    def __getitem__(self, key: Union[
-        None,
-        slice,
-        ellipsis,
-        SupportsIndex,
-        _ArrayLikeInt_co,
-        Tuple[None | slice | ellipsis | _ArrayLikeInt_co | SupportsIndex, ...],
-    ]) -> matrix[Any, _DType_co]: ...
+    def __getitem__(self, key: (
+        SupportsIndex
+        | _ArrayLikeInt_co
+        | Tuple[SupportsIndex | _ArrayLikeInt_co, ...]
+    )) -> Any: ...
+    @overload
+    def __getitem__(self, key: (
+        None
+        | slice
+        | ellipsis
+        | SupportsIndex
+        | _ArrayLikeInt_co
+        | Tuple[None | slice | ellipsis | _ArrayLikeInt_co | SupportsIndex, ...]
+    )) -> matrix[Any, _DType_co]: ...
     @overload
     def __getitem__(self: NDArray[void], key: str) -> matrix[Any, dtype[Any]]: ...
     @overload
diff --git a/numpy/core/_asarray.pyi b/numpy/core/_asarray.pyi
index fee9b7b6e..477b59c7d 100644
--- a/numpy/core/_asarray.pyi
+++ b/numpy/core/_asarray.pyi
@@ -19,7 +19,7 @@ _RequirementsWithE = Union[_Requirements, _E]
 def require(
     a: _ArrayType,
     dtype: None = ...,
-    requirements: Union[None, _Requirements, Iterable[_Requirements]] = ...,
+    requirements: None | _Requirements | Iterable[_Requirements] = ...,
     *,
     like: ArrayLike = ...
 ) -> _ArrayType: ...
@@ -27,7 +27,7 @@ def require(
 def require(
     a: object,
     dtype: DTypeLike = ...,
-    requirements: Union[_E, Iterable[_RequirementsWithE]] = ...,
+    requirements: _E | Iterable[_RequirementsWithE] = ...,
     *,
     like: ArrayLike = ...
 ) -> ndarray: ...
@@ -35,7 +35,7 @@ def require(
 def require(
     a: object,
     dtype: DTypeLike = ...,
-    requirements: Union[None, _Requirements, Iterable[_Requirements]] = ...,
+    requirements: None | _Requirements | Iterable[_Requirements] = ...,
     *,
     like: ArrayLike = ...
 ) -> ndarray: ...
diff --git a/numpy/core/_type_aliases.pyi b/numpy/core/_type_aliases.pyi
index c10d072f9..660b1d2b6 100644
--- a/numpy/core/_type_aliases.pyi
+++ b/numpy/core/_type_aliases.pyi
@@ -1,4 +1,4 @@
-from typing import Dict, Union, Type, List, TypedDict
+from typing import Dict, Type, List, TypedDict
 
 from numpy import generic, signedinteger, unsignedinteger, floating, complexfloating
 
@@ -9,5 +9,5 @@ class _SCTypes(TypedDict):
     complex: List[Type[complexfloating]]
     others: List[type]
 
-sctypeDict: Dict[Union[int, str], Type[generic]]
+sctypeDict: Dict[int | str, Type[generic]]
 sctypes: _SCTypes
diff --git a/numpy/core/_ufunc_config.pyi b/numpy/core/_ufunc_config.pyi
index 7e1b39be9..1688221a9 100644
--- a/numpy/core/_ufunc_config.pyi
+++ b/numpy/core/_ufunc_config.pyi
@@ -1,4 +1,4 @@
-from typing import Union, Callable, Any, Literal, TypedDict
+from typing import Callable, Any, Literal, TypedDict
 
 from numpy import _SupportsWrite
 
@@ -29,8 +29,8 @@ def geterr() -> _ErrDict: ...
 def setbufsize(size: int) -> int: ...
 def getbufsize() -> int: ...
 def seterrcall(
-    func: Union[None, _ErrFunc, _SupportsWrite[str]]
-) -> Union[None, _ErrFunc, _SupportsWrite[str]]: ...
-def geterrcall() -> Union[None, _ErrFunc, _SupportsWrite[str]]: ...
+    func: None | _ErrFunc | _SupportsWrite[str]
+) -> None | _ErrFunc | _SupportsWrite[str]: ...
+def geterrcall() -> None | _ErrFunc | _SupportsWrite[str]: ...
 
 # See `numpy/__init__.pyi` for the `errstate` class
diff --git a/numpy/core/arrayprint.pyi b/numpy/core/arrayprint.pyi
index b18a554d6..5c33a21d3 100644
--- a/numpy/core/arrayprint.pyi
+++ b/numpy/core/arrayprint.pyi
@@ -1,5 +1,5 @@
 from types import TracebackType
-from typing import Any, Callable, Union, Type, Literal, TypedDict, SupportsIndex
+from typing import Any, Callable, Type, Literal, TypedDict, SupportsIndex
 
 # Using a private class is by no means ideal, but it is simply a consequence
 # of a `contextlib.context` returning an instance of aforementioned class
diff --git a/numpy/core/einsumfunc.pyi b/numpy/core/einsumfunc.pyi
index 9c020f8ba..ec34c3c92 100644
--- a/numpy/core/einsumfunc.pyi
+++ b/numpy/core/einsumfunc.pyi
@@ -30,9 +30,7 @@ _ArrayType = TypeVar(
     bound=ndarray[Any, dtype[Union[bool_, number[Any]]]],
 )
 
-_OptimizeKind = Union[
-    None, bool, Literal["greedy", "optimal"], Sequence[Any]
-]
+_OptimizeKind = None | bool | Literal["greedy", "optimal"] | Sequence[Any]
 _CastingSafe = Literal["no", "equiv", "safe", "same_kind"]
 _CastingUnsafe = Literal["unsafe"]
 
diff --git a/numpy/core/fromnumeric.pyi b/numpy/core/fromnumeric.pyi
index b09ed19da..12847ae4f 100644
--- a/numpy/core/fromnumeric.pyi
+++ b/numpy/core/fromnumeric.pyi
@@ -18,6 +18,7 @@ from numpy import (
 from numpy.typing import (
     DTypeLike,
     ArrayLike,
+    NDArray,
     _ShapeLike,
     _Shape,
     _ArrayLikeBool_co,
@@ -86,7 +87,7 @@ def swapaxes(
 
 def transpose(
     a: ArrayLike,
-    axes: Union[None, Sequence[int], ndarray] = ...
+    axes: None | Sequence[int] | NDArray[Any] = ...
 ) -> ndarray: ...
 
 def partition(
@@ -94,7 +95,7 @@ def partition(
     kth: _ArrayLikeInt_co,
     axis: None | int = ...,
     kind: _PartitionKind = ...,
-    order: Union[None, str, Sequence[str]] = ...,
+    order: None | str | Sequence[str] = ...,
 ) -> ndarray: ...
 
 def argpartition(
@@ -102,21 +103,21 @@ def argpartition(
     kth: _ArrayLikeInt_co,
     axis: None | int = ...,
     kind: _PartitionKind = ...,
-    order: Union[None, str, Sequence[str]] = ...,
+    order: None | str | Sequence[str] = ...,
 ) -> Any: ...
 
 def sort(
     a: ArrayLike,
     axis: None | int = ...,
     kind: None | _SortKind = ...,
-    order: Union[None, str, Sequence[str]] = ...,
+    order: None | str | Sequence[str] = ...,
 ) -> ndarray: ...
 
 def argsort(
     a: ArrayLike,
     axis: None | int = ...,
     kind: None | _SortKind = ...,
-    order: Union[None, str, Sequence[str]] = ...,
+    order: None | str | Sequence[str] = ...,
 ) -> ndarray: ...
 
 @overload
diff --git a/numpy/core/multiarray.pyi b/numpy/core/multiarray.pyi
index 62b4b8bfc..b410ffe21 100644
--- a/numpy/core/multiarray.pyi
+++ b/numpy/core/multiarray.pyi
@@ -295,14 +295,14 @@ def unravel_index(
 def ravel_multi_index(  # type: ignore[misc]
     multi_index: Sequence[_IntLike_co],
     dims: Sequence[SupportsIndex],
-    mode: Union[_ModeKind, Tuple[_ModeKind, ...]] = ...,
+    mode: _ModeKind | Tuple[_ModeKind, ...] = ...,
     order: _OrderCF = ...,
 ) -> intp: ...
 @overload
 def ravel_multi_index(
     multi_index: Sequence[_ArrayLikeInt_co],
     dims: Sequence[SupportsIndex],
-    mode: Union[_ModeKind, Tuple[_ModeKind, ...]] = ...,
+    mode: _ModeKind | Tuple[_ModeKind, ...] = ...,
     order: _OrderCF = ...,
 ) -> NDArray[intp]: ...
 
@@ -382,7 +382,7 @@ def lexsort(
 ) -> Any: ...
 
 def can_cast(
-    from_: Union[ArrayLike, DTypeLike],
+    from_: ArrayLike | DTypeLike,
     to: DTypeLike,
     casting: None | _CastingKind = ...,
 ) -> bool: ...
@@ -392,7 +392,7 @@ def min_scalar_type(
 ) -> dtype[Any]: ...
 
 def result_type(
-    *arrays_and_dtypes: Union[ArrayLike, DTypeLike],
+    *arrays_and_dtypes: ArrayLike | DTypeLike,
 ) -> dtype[Any]: ...
 
 @overload
diff --git a/numpy/lib/_version.pyi b/numpy/lib/_version.pyi
index 3581d639b..e8b5026ca 100644
--- a/numpy/lib/_version.pyi
+++ b/numpy/lib/_version.pyi
@@ -1,4 +1,4 @@
-from typing import Union, List
+from typing import List
 
 __all__: List[str]
 
@@ -11,9 +11,9 @@ class NumpyVersion:
     pre_release: str
     is_devversion: bool
     def __init__(self, vstring: str) -> None: ...
-    def __lt__(self, other: Union[str, NumpyVersion]) -> bool: ...
-    def __le__(self, other: Union[str, NumpyVersion]) -> bool: ...
-    def __eq__(self, other: Union[str, NumpyVersion]) -> bool: ...  # type: ignore[override]
-    def __ne__(self, other: Union[str, NumpyVersion]) -> bool: ...  # type: ignore[override]
-    def __gt__(self, other: Union[str, NumpyVersion]) -> bool: ...
-    def __ge__(self, other: Union[str, NumpyVersion]) -> bool: ...
+    def __lt__(self, other: str | NumpyVersion) -> bool: ...
+    def __le__(self, other: str | NumpyVersion) -> bool: ...
+    def __eq__(self, other: str | NumpyVersion) -> bool: ...  # type: ignore[override]
+    def __ne__(self, other: str | NumpyVersion) -> bool: ...  # type: ignore[override]
+    def __gt__(self, other: str | NumpyVersion) -> bool: ...
+    def __ge__(self, other: str | NumpyVersion) -> bool: ...
diff --git a/numpy/lib/arraysetops.pyi b/numpy/lib/arraysetops.pyi
index 6f13ec74b..492affb10 100644
--- a/numpy/lib/arraysetops.pyi
+++ b/numpy/lib/arraysetops.pyi
@@ -2,7 +2,6 @@ from typing import (
     Literal as L,
     Any,
     List,
-    Union,
     TypeVar,
     Tuple,
     overload,
diff --git a/numpy/lib/index_tricks.pyi b/numpy/lib/index_tricks.pyi
index d16faf81a..6aa8b2571 100644
--- a/numpy/lib/index_tricks.pyi
+++ b/numpy/lib/index_tricks.pyi
@@ -5,7 +5,6 @@ from typing import (
     Generic,
     overload,
     List,
-    Union,
     Sequence,
     Literal,
     SupportsIndex,
@@ -79,12 +78,12 @@ class nd_grid(Generic[_BoolType]):
     @overload
     def __getitem__(
         self: nd_grid[Literal[False]],
-        key: Union[slice, Sequence[slice]],
+        key: slice | Sequence[slice],
     ) -> NDArray[Any]: ...
     @overload
     def __getitem__(
         self: nd_grid[Literal[True]],
-        key: Union[slice, Sequence[slice]],
+        key: slice | Sequence[slice],
     ) -> List[NDArray[Any]]: ...
 
 class MGridClass(nd_grid[Literal[False]]):
diff --git a/numpy/lib/ufunclike.pyi b/numpy/lib/ufunclike.pyi
index 03f08ebff..bd48816e5 100644
--- a/numpy/lib/ufunclike.pyi
+++ b/numpy/lib/ufunclike.pyi
@@ -1,4 +1,4 @@
-from typing import Any, overload, TypeVar, List, Union
+from typing import Any, overload, TypeVar, List
 
 from numpy import floating, bool_, object_, ndarray
 from numpy.typing import (
@@ -29,7 +29,7 @@ def fix(
 ) -> NDArray[object_]: ...
 @overload
 def fix(
-    x: Union[_ArrayLikeFloat_co, _ArrayLikeObject_co],
+    x: _ArrayLikeFloat_co | _ArrayLikeObject_co,
     out: _ArrayType,
 ) -> _ArrayType: ...
 
diff --git a/numpy/lib/utils.pyi b/numpy/lib/utils.pyi
index f42ba9efb..ef4f8cd4a 100644
--- a/numpy/lib/utils.pyi
+++ b/numpy/lib/utils.pyi
@@ -8,7 +8,6 @@ from typing import (
     Sequence,
     Tuple,
     TypeVar,
-    Union,
     Protocol,
 )
 
@@ -67,7 +66,7 @@ def deprecate_with_doc(msg: None | str) -> _Deprecate: ...
 # implementing the `__array_interface__` protocol. The caveat is
 # that certain keys, marked as optional in the spec, must be present for
 #  `byte_bounds`. This concerns `"strides"` and `"data"`.
-def byte_bounds(a: Union[generic, ndarray[Any, Any]]) -> Tuple[int, int]: ...
+def byte_bounds(a: generic | ndarray[Any, Any]) -> Tuple[int, int]: ...
 
 def who(vardict: None | Mapping[str, ndarray[Any, Any]] = ...) -> None: ...
 
@@ -85,10 +84,10 @@ def source(
 
 def lookfor(
     what: str,
-    module: Union[None, str, Sequence[str]] = ...,
+    module: None | str | Sequence[str] = ...,
     import_modules: bool = ...,
     regenerate: bool = ...,
     output: None | _SupportsWrite[str] =...,
 ) -> None: ...
 
-def safe_eval(source: Union[str, AST]) -> Any: ...
+def safe_eval(source: str | AST) -> Any: ...
diff --git a/numpy/random/_generator.pyi b/numpy/random/_generator.pyi
index 11499501e..a1e25871a 100644
--- a/numpy/random/_generator.pyi
+++ b/numpy/random/_generator.pyi
@@ -76,7 +76,7 @@ class Generator:
     def standard_normal(  # type: ignore[misc]
         self,
         size: None = ...,
-        dtype: Union[_DTypeLikeFloat32, _DTypeLikeFloat64] = ...,
+        dtype: _DTypeLikeFloat32 | _DTypeLikeFloat64 = ...,
         out: None = ...,
     ) -> float: ...
     @overload
@@ -112,7 +112,7 @@ class Generator:
     def standard_exponential(  # type: ignore[misc]
         self,
         size: None = ...,
-        dtype: Union[_DTypeLikeFloat32, _DTypeLikeFloat64] = ...,
+        dtype: _DTypeLikeFloat32 | _DTypeLikeFloat64 = ...,
         method: Literal["zig", "inv"] = ...,
         out: None = ...,
     ) -> float: ...
@@ -155,7 +155,7 @@ class Generator:
     def random(  # type: ignore[misc]
         self,
         size: None = ...,
-        dtype: Union[_DTypeLikeFloat32, _DTypeLikeFloat64] = ...,
+        dtype: _DTypeLikeFloat32 | _DTypeLikeFloat64 = ...,
         out: None = ...,
     ) -> float: ...
     @overload
@@ -218,7 +218,7 @@ class Generator:
         low: int,
         high: None | int = ...,
         size: None = ...,
-        dtype: Union[_DTypeLikeInt, _DTypeLikeUInt] = ...,
+        dtype: _DTypeLikeInt | _DTypeLikeUInt = ...,
         endpoint: bool = ...,
     ) -> int: ...
     @overload
@@ -243,7 +243,7 @@ class Generator:
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[dtype[int8], Type[int8], _Int8Codes, _SupportsDType[dtype[int8]]] = ...,
+        dtype: dtype[int8] | Type[int8] | _Int8Codes | _SupportsDType[dtype[int8]] = ...,
         endpoint: bool = ...,
     ) -> ndarray[Any, dtype[int8]]: ...
     @overload
@@ -252,7 +252,7 @@ class Generator:
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[dtype[int16], Type[int16], _Int16Codes, _SupportsDType[dtype[int16]]] = ...,
+        dtype: dtype[int16] | Type[int16] | _Int16Codes | _SupportsDType[dtype[int16]] = ...,
         endpoint: bool = ...,
     ) -> ndarray[Any, dtype[int16]]: ...
     @overload
@@ -261,16 +261,16 @@ class Generator:
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[dtype[int32], Type[int32], _Int32Codes, _SupportsDType[dtype[int32]]] = ...,
+        dtype: dtype[int32] | Type[int32] | _Int32Codes | _SupportsDType[dtype[int32]] = ...,
         endpoint: bool = ...,
-    ) -> ndarray[Any, dtype[Union[int32]]]: ...
+    ) -> ndarray[Any, dtype[int32]]: ...
     @overload
     def integers(  # type: ignore[misc]
         self,
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: None | Union[dtype[int64], Type[int64], _Int64Codes, _SupportsDType[dtype[int64]]] = ...,
+        dtype: None | dtype[int64] | Type[int64] | _Int64Codes | _SupportsDType[dtype[int64]] = ...,
         endpoint: bool = ...,
     ) -> ndarray[Any, dtype[int64]]: ...
     @overload
@@ -279,7 +279,7 @@ class Generator:
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[dtype[uint8], Type[uint8], _UInt8Codes, _SupportsDType[dtype[uint8]]] = ...,
+        dtype: dtype[uint8] | Type[uint8] | _UInt8Codes | _SupportsDType[dtype[uint8]] = ...,
         endpoint: bool = ...,
     ) -> ndarray[Any, dtype[uint8]]: ...
     @overload
@@ -288,20 +288,16 @@ class Generator:
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[
-            dtype[uint16], Type[uint16], _UInt16Codes, _SupportsDType[dtype[uint16]]
-        ] = ...,
+        dtype: dtype[uint16] | Type[uint16] | _UInt16Codes | _SupportsDType[dtype[uint16]] = ...,
         endpoint: bool = ...,
-    ) -> ndarray[Any, dtype[Union[uint16]]]: ...
+    ) -> ndarray[Any, dtype[uint16]]: ...
     @overload
     def integers(  # type: ignore[misc]
         self,
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[
-            dtype[uint32], Type[uint32], _UInt32Codes, _SupportsDType[dtype[uint32]]
-        ] = ...,
+        dtype: dtype[uint32] | Type[uint32] | _UInt32Codes | _SupportsDType[dtype[uint32]] = ...,
         endpoint: bool = ...,
     ) -> ndarray[Any, dtype[uint32]]: ...
     @overload
@@ -310,9 +306,7 @@ class Generator:
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[
-            dtype[uint64], Type[uint64], _UInt64Codes, _SupportsDType[dtype[uint64]]
-        ] = ...,
+        dtype: dtype[uint64] | Type[uint64] | _UInt64Codes | _SupportsDType[dtype[uint64]] = ...,
         endpoint: bool = ...,
     ) -> ndarray[Any, dtype[uint64]]: ...
     @overload
@@ -321,9 +315,7 @@ class Generator:
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[
-            dtype[int_], Type[int], Type[int_], _IntCodes, _SupportsDType[dtype[int_]]
-        ] = ...,
+        dtype: dtype[int_] | Type[int] | Type[int_] | _IntCodes | _SupportsDType[dtype[int_]] = ...,
         endpoint: bool = ...,
     ) -> ndarray[Any, dtype[int_]]: ...
     @overload
@@ -332,10 +324,10 @@ class Generator:
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[dtype[uint], Type[uint], _UIntCodes, _SupportsDType[dtype[uint]]] = ...,
+        dtype: dtype[uint] | Type[uint] | _UIntCodes | _SupportsDType[dtype[uint]] = ...,
         endpoint: bool = ...,
     ) -> ndarray[Any, dtype[uint]]: ...
-    # TODO: Use a TypeVar _T here to get away from Any output?  Should be int->ndarray[Any,dtype[int64]], ArrayLike[_T] -> Union[_T, ndarray[Any,Any]]
+    # TODO: Use a TypeVar _T here to get away from Any output?  Should be int->ndarray[Any,dtype[int64]], ArrayLike[_T] -> _T | ndarray[Any,Any]
     @overload
     def choice(
         self,
@@ -399,7 +391,7 @@ class Generator:
         self,
         shape: float,
         size: None = ...,
-        dtype: Union[_DTypeLikeFloat32, _DTypeLikeFloat64] = ...,
+        dtype: _DTypeLikeFloat32 | _DTypeLikeFloat64 = ...,
         out: None = ...,
     ) -> float: ...
     @overload
@@ -641,5 +633,5 @@ class Generator:
     def shuffle(self, x: ArrayLike, axis: int = ...) -> None: ...
 
 def default_rng(
-    seed: Union[None, _ArrayLikeInt_co, SeedSequence, BitGenerator, Generator] = ...
+    seed: None | _ArrayLikeInt_co | SeedSequence | BitGenerator | Generator = ...
 ) -> Generator: ...
diff --git a/numpy/random/_mt19937.pyi b/numpy/random/_mt19937.pyi
index 820f27392..1494aad59 100644
--- a/numpy/random/_mt19937.pyi
+++ b/numpy/random/_mt19937.pyi
@@ -1,4 +1,4 @@
-from typing import Any, Union, TypedDict
+from typing import Any, TypedDict
 
 from numpy import dtype, ndarray, uint32
 from numpy.random.bit_generator import BitGenerator, SeedSequence
@@ -13,7 +13,7 @@ class _MT19937State(TypedDict):
     state: _MT19937Internal
 
 class MT19937(BitGenerator):
-    def __init__(self, seed: Union[None, _ArrayLikeInt_co, SeedSequence] = ...) -> None: ...
+    def __init__(self, seed: None | _ArrayLikeInt_co | SeedSequence = ...) -> None: ...
     def _legacy_seeding(self, seed: _ArrayLikeInt_co) -> None: ...
     def jumped(self, jumps: int = ...) -> MT19937: ...
     @property
diff --git a/numpy/random/_pcg64.pyi b/numpy/random/_pcg64.pyi
index 4881a987e..b1e73565e 100644
--- a/numpy/random/_pcg64.pyi
+++ b/numpy/random/_pcg64.pyi
@@ -1,4 +1,4 @@
-from typing import Union, TypedDict
+from typing import TypedDict
 
 from numpy.random.bit_generator import BitGenerator, SeedSequence
 from numpy.typing import _ArrayLikeInt_co
@@ -14,7 +14,7 @@ class _PCG64State(TypedDict):
     uinteger: int
 
 class PCG64(BitGenerator):
-    def __init__(self, seed: Union[None, _ArrayLikeInt_co, SeedSequence] = ...) -> None: ...
+    def __init__(self, seed: None | _ArrayLikeInt_co | SeedSequence = ...) -> None: ...
     def jumped(self, jumps: int = ...) -> PCG64: ...
     @property
     def state(
@@ -28,7 +28,7 @@ class PCG64(BitGenerator):
     def advance(self, delta: int) -> PCG64: ...
 
 class PCG64DXSM(BitGenerator):
-    def __init__(self, seed: Union[None, _ArrayLikeInt_co, SeedSequence] = ...) -> None: ...
+    def __init__(self, seed: None | _ArrayLikeInt_co | SeedSequence = ...) -> None: ...
     def jumped(self, jumps: int = ...) -> PCG64DXSM: ...
     @property
     def state(
diff --git a/numpy/random/_philox.pyi b/numpy/random/_philox.pyi
index dd1c5e6e9..1f289f5de 100644
--- a/numpy/random/_philox.pyi
+++ b/numpy/random/_philox.pyi
@@ -1,4 +1,4 @@
-from typing import Any, Union, TypedDict
+from typing import Any, TypedDict
 
 from numpy import dtype, ndarray, uint64
 from numpy.random.bit_generator import BitGenerator, SeedSequence
@@ -19,9 +19,9 @@ class _PhiloxState(TypedDict):
 class Philox(BitGenerator):
     def __init__(
         self,
-        seed: Union[None, _ArrayLikeInt_co, SeedSequence] = ...,
-        counter: Union[None, _ArrayLikeInt_co] = ...,
-        key: Union[None, _ArrayLikeInt_co] = ...,
+        seed: None | _ArrayLikeInt_co | SeedSequence = ...,
+        counter: None | _ArrayLikeInt_co = ...,
+        key: None | _ArrayLikeInt_co = ...,
     ) -> None: ...
     @property
     def state(
diff --git a/numpy/random/_sfc64.pyi b/numpy/random/_sfc64.pyi
index 94d11a210..333aa92c4 100644
--- a/numpy/random/_sfc64.pyi
+++ b/numpy/random/_sfc64.pyi
@@ -1,4 +1,4 @@
-from typing import Any, Union, TypedDict
+from typing import Any, TypedDict
 
 from numpy import dtype as dtype
 from numpy import ndarray as ndarray
@@ -16,7 +16,7 @@ class _SFC64State(TypedDict):
     uinteger: int
 
 class SFC64(BitGenerator):
-    def __init__(self, seed: Union[None, _ArrayLikeInt_co, SeedSequence] = ...) -> None: ...
+    def __init__(self, seed: None | _ArrayLikeInt_co | SeedSequence = ...) -> None: ...
     @property
     def state(
         self,
diff --git a/numpy/random/bit_generator.pyi b/numpy/random/bit_generator.pyi
index 5d8b12651..071301e5d 100644
--- a/numpy/random/bit_generator.pyi
+++ b/numpy/random/bit_generator.pyi
@@ -36,7 +36,7 @@ _DTypeLikeUint64 = Union[
 ]
 
 class _SeedSeqState(TypedDict):
-    entropy: Union[None, int, Sequence[int]]
+    entropy: None | int | Sequence[int]
     spawn_key: Tuple[int, ...]
     pool_size: int
     n_children_spawned: int
@@ -52,8 +52,8 @@ class _Interface(NamedTuple):
 class ISeedSequence(abc.ABC):
     @abc.abstractmethod
     def generate_state(
-        self, n_words: int, dtype: Union[_DTypeLikeUint32, _DTypeLikeUint64] = ...
-    ) -> ndarray[Any, dtype[Union[uint32, uint64]]]: ...
+        self, n_words: int, dtype: _DTypeLikeUint32 | _DTypeLikeUint64 = ...
+    ) -> ndarray[Any, dtype[uint32 | uint64]]: ...
 
 class ISpawnableSeedSequence(ISeedSequence):
     @abc.abstractmethod
@@ -61,19 +61,19 @@ class ISpawnableSeedSequence(ISeedSequence):
 
 class SeedlessSeedSequence(ISpawnableSeedSequence):
     def generate_state(
-        self, n_words: int, dtype: Union[_DTypeLikeUint32, _DTypeLikeUint64] = ...
-    ) -> ndarray[Any, dtype[Union[uint32, uint64]]]: ...
+        self, n_words: int, dtype: _DTypeLikeUint32 | _DTypeLikeUint64 = ...
+    ) -> ndarray[Any, dtype[uint32 | uint64]]: ...
     def spawn(self: _T, n_children: int) -> List[_T]: ...
 
 class SeedSequence(ISpawnableSeedSequence):
-    entropy: Union[None, int, Sequence[int]]
+    entropy: None | int | Sequence[int]
     spawn_key: Tuple[int, ...]
     pool_size: int
     n_children_spawned: int
     pool: ndarray[Any, dtype[uint32]]
     def __init__(
         self,
-        entropy: Union[None, int, Sequence[int], _ArrayLikeInt_co] = ...,
+        entropy: None | int | Sequence[int] | _ArrayLikeInt_co = ...,
         *,
         spawn_key: Sequence[int] = ...,
         pool_size: int = ...,
@@ -85,13 +85,13 @@ class SeedSequence(ISpawnableSeedSequence):
         self,
     ) -> _SeedSeqState: ...
     def generate_state(
-        self, n_words: int, dtype: Union[_DTypeLikeUint32, _DTypeLikeUint64] = ...
-    ) -> ndarray[Any, dtype[Union[uint32, uint64]]]: ...
+        self, n_words: int, dtype: _DTypeLikeUint32 | _DTypeLikeUint64 = ...
+    ) -> ndarray[Any, dtype[uint32 | uint64]]: ...
     def spawn(self, n_children: int) -> List[SeedSequence]: ...
 
 class BitGenerator(abc.ABC):
     lock: Lock
-    def __init__(self, seed: Union[None, _ArrayLikeInt_co, SeedSequence] = ...) -> None: ...
+    def __init__(self, seed: None | _ArrayLikeInt_co | SeedSequence = ...) -> None: ...
     def __getstate__(self) -> Dict[str, Any]: ...
     def __setstate__(self, state: Dict[str, Any]) -> None: ...
     def __reduce__(
diff --git a/numpy/random/mtrand.pyi b/numpy/random/mtrand.pyi
index 0769ff19e..87bdf8141 100644
--- a/numpy/random/mtrand.pyi
+++ b/numpy/random/mtrand.pyi
@@ -62,7 +62,7 @@ _DTypeLikeFloat64 = Union[
 
 class RandomState:
     _bit_generator: BitGenerator
-    def __init__(self, seed: Union[None, _ArrayLikeInt_co, BitGenerator] = ...) -> None: ...
+    def __init__(self, seed: None | _ArrayLikeInt_co | BitGenerator = ...) -> None: ...
     def __repr__(self) -> str: ...
     def __str__(self) -> str: ...
     def __getstate__(self) -> Dict[str, Any]: ...
@@ -74,9 +74,9 @@ class RandomState:
     @overload
     def get_state(
         self, legacy: Literal[True] = ...
-    ) -> Union[Dict[str, Any], Tuple[str, ndarray[Any, dtype[uint32]], int, int, float]]: ...
+    ) -> Dict[str, Any] | Tuple[str, ndarray[Any, dtype[uint32]], int, int, float]: ...
     def set_state(
-        self, state: Union[Dict[str, Any], Tuple[str, ndarray[Any, dtype[uint32]], int, int, float]]
+        self, state: Dict[str, Any] | Tuple[str, ndarray[Any, dtype[uint32]], int, int, float]
     ) -> None: ...
     @overload
     def random_sample(self, size: None = ...) -> float: ...  # type: ignore[misc]
@@ -126,7 +126,7 @@ class RandomState:
         low: int,
         high: None | int = ...,
         size: None = ...,
-        dtype: Union[_DTypeLikeInt, _DTypeLikeUInt] = ...,
+        dtype: _DTypeLikeInt | _DTypeLikeUInt = ...,
     ) -> int: ...
     @overload
     def randint(  # type: ignore[misc]
@@ -149,7 +149,7 @@ class RandomState:
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[dtype[int8], Type[int8], _Int8Codes, _SupportsDType[dtype[int8]]] = ...,
+        dtype: dtype[int8] | Type[int8] | _Int8Codes | _SupportsDType[dtype[int8]] = ...,
     ) -> ndarray[Any, dtype[int8]]: ...
     @overload
     def randint(  # type: ignore[misc]
@@ -157,7 +157,7 @@ class RandomState:
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[dtype[int16], Type[int16], _Int16Codes, _SupportsDType[dtype[int16]]] = ...,
+        dtype: dtype[int16] | Type[int16] | _Int16Codes | _SupportsDType[dtype[int16]] = ...,
     ) -> ndarray[Any, dtype[int16]]: ...
     @overload
     def randint(  # type: ignore[misc]
@@ -165,8 +165,8 @@ class RandomState:
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[dtype[int32], Type[int32], _Int32Codes, _SupportsDType[dtype[int32]]] = ...,
-    ) -> ndarray[Any, dtype[Union[int32]]]: ...
+        dtype: dtype[int32] | Type[int32] | _Int32Codes | _SupportsDType[dtype[int32]] = ...,
+    ) -> ndarray[Any, dtype[int32]]: ...
     @overload
     def randint(  # type: ignore[misc]
         self,
@@ -181,7 +181,7 @@ class RandomState:
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[dtype[uint8], Type[uint8], _UInt8Codes, _SupportsDType[dtype[uint8]]] = ...,
+        dtype: dtype[uint8] | Type[uint8] | _UInt8Codes | _SupportsDType[dtype[uint8]] = ...,
     ) -> ndarray[Any, dtype[uint8]]: ...
     @overload
     def randint(  # type: ignore[misc]
@@ -189,19 +189,15 @@ class RandomState:
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[
-            dtype[uint16], Type[uint16], _UInt16Codes, _SupportsDType[dtype[uint16]]
-        ] = ...,
-    ) -> ndarray[Any, dtype[Union[uint16]]]: ...
+        dtype: dtype[uint16] | Type[uint16] | _UInt16Codes | _SupportsDType[dtype[uint16]] = ...,
+    ) -> ndarray[Any, dtype[uint16]]: ...
     @overload
     def randint(  # type: ignore[misc]
         self,
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[
-            dtype[uint32], Type[uint32], _UInt32Codes, _SupportsDType[dtype[uint32]]
-        ] = ...,
+        dtype: dtype[uint32] | Type[uint32] | _UInt32Codes | _SupportsDType[dtype[uint32]] = ...,
     ) -> ndarray[Any, dtype[uint32]]: ...
     @overload
     def randint(  # type: ignore[misc]
@@ -209,9 +205,7 @@ class RandomState:
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[
-            dtype[uint64], Type[uint64], _UInt64Codes, _SupportsDType[dtype[uint64]]
-        ] = ...,
+        dtype: dtype[uint64] | Type[uint64] | _UInt64Codes | _SupportsDType[dtype[uint64]] = ...,
     ) -> ndarray[Any, dtype[uint64]]: ...
     @overload
     def randint(  # type: ignore[misc]
@@ -219,9 +213,7 @@ class RandomState:
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[
-            dtype[int_], Type[int], Type[int_], _IntCodes, _SupportsDType[dtype[int_]]
-        ] = ...,
+        dtype: dtype[int_] | Type[int] | Type[int_] | _IntCodes | _SupportsDType[dtype[int_]] = ...,
     ) -> ndarray[Any, dtype[int_]]: ...
     @overload
     def randint(  # type: ignore[misc]
@@ -229,7 +221,7 @@ class RandomState:
         low: _ArrayLikeInt_co,
         high: None | _ArrayLikeInt_co = ...,
         size: None | _ShapeLike = ...,
-        dtype: Union[dtype[uint], Type[uint], _UIntCodes, _SupportsDType[dtype[uint]]] = ...,
+        dtype: dtype[uint] | Type[uint] | _UIntCodes | _SupportsDType[dtype[uint]] = ...,
     ) -> ndarray[Any, dtype[uint]]: ...
     def bytes(self, length: int) -> bytes: ...
     @overload
diff --git a/numpy/typing/_callable.pyi b/numpy/typing/_callable.pyi
index e1149f26a..59af13e01 100644
--- a/numpy/typing/_callable.pyi
+++ b/numpy/typing/_callable.pyi
@@ -11,7 +11,6 @@ See the `Mypy documentation`_ on protocols for more details.
 from __future__ import annotations
 
 from typing import (
-    Union,
     TypeVar,
     overload,
     Any,
@@ -310,11 +309,11 @@ class _ComplexOp(Protocol[_NBit1]):
     @overload
     def __call__(
         self,
-        other: Union[
-            integer[_NBit2],
-            floating[_NBit2],
-            complexfloating[_NBit2, _NBit2],
-        ], /,
+        other: (
+            integer[_NBit2]
+            | floating[_NBit2]
+            | complexfloating[_NBit2, _NBit2]
+        ), /,
     ) -> complexfloating[_NBit1 | _NBit2, _NBit1 | _NBit2]: ...
 
 class _NumberOp(Protocol):
diff --git a/numpy/typing/tests/data/reveal/nbit_base_example.pyi b/numpy/typing/tests/data/reveal/nbit_base_example.pyi
index d34f6f69a..a7cc68194 100644
--- a/numpy/typing/tests/data/reveal/nbit_base_example.pyi
+++ b/numpy/typing/tests/data/reveal/nbit_base_example.pyi
@@ -1,11 +1,13 @@
-from typing import TypeVar, Union
+from __future__ import annotations
+
+from typing import TypeVar
 import numpy as np
 import numpy.typing as npt
 
 T1 = TypeVar("T1", bound=npt.NBitBase)
 T2 = TypeVar("T2", bound=npt.NBitBase)
 
-def add(a: np.floating[T1], b: np.integer[T2]) -> np.floating[Union[T1, T2]]:
+def add(a: np.floating[T1], b: np.integer[T2]) -> np.floating[T1 | T2]:
     return a + b
 
 i8: np.int64