numpy
diff --git a/‎numpy/__init__.pyi‎
Lines changed: 32 additions & 3 deletions b/‎numpy/__init__.pyi‎
Lines changed: 32 additions & 3 deletions
diff --git a/‎numpy/typing/tests/data/reveal/scalars.pyi‎
Lines changed: 29 additions & 0 deletions b/‎numpy/typing/tests/data/reveal/scalars.pyi‎
Lines changed: 29 additions & 0 deletions
@@ -2848,12 +2848,41 @@ class bool(generic):
 
 bool_: TypeAlias = bool
 
+_StringType = TypeVar("_StringType", bound=str | bytes)
+_StringType = TypeVar("_StringType", bound=str | bytes)
+_ShapeType = TypeVar("_ShapeType", bound=Any)
+_ObjectType = TypeVar("_ObjectType", bound=object)
+
+# A sequence-like interface like `collections.abc.Sequence`, but without the
+# irrelevant methods.
+class _SimpleSequence(Protocol):
+    def __len__(self, /) -> int: ...
+    def __getitem__(self, index: int, /) -> Any: ...
+
+# The `object_` constructor returns the passed object, so instances with type
+# `object_` cannot exists (at runtime).
 class object_(generic):
-    def __init__(self, value: object = ..., /) -> None: ...
+    @overload
+    def __new__(cls, nothing_to_see_here: None = ..., /) -> None: ...
+    @overload
+    def __new__(cls, stringy: _StringType, /) -> _StringType: ...
+    @overload
+    def __new__(
+        cls,
+        array: ndarray[_ShapeType, Any], /,
+    ) -> ndarray[_ShapeType, dtype[object_]]: ...
+    @overload
+    def __new__(cls, sequence: _SimpleSequence, /) -> NDArray[object_]: ...
+    @overload
+    def __new__(cls, value: _ObjectType, /) -> _ObjectType: ...
+    # catch-all
+    @overload
+    def __new__(cls, value: Any = ..., /) -> object | NDArray[object_]: ...
+
     @property
-    def real(self: _ArraySelf) -> _ArraySelf: ...
+    def real(self) -> object_: ...
     @property
-    def imag(self: _ArraySelf) -> _ArraySelf: ...
+    def imag(self) -> object_: ...
     # The 3 protocols below may or may not raise,
     # depending on the underlying object
     def __int__(self) -> int: ...
 
@@ -19,6 +19,11 @@ m: np.timedelta64
 U: np.str_
 S: np.bytes_
 V: np.void
+O: np.object_  # cannot exists at runtime
+
+array_nd: np.ndarray[Any, Any]
+array_0d: np.ndarray[tuple[()], Any]
+array_2d_2x2: np.ndarray[tuple[Literal[2], Literal[2]], Any]
 
 assert_type(c8.real, np.float32)
 assert_type(c8.imag, np.float32)
@@ -156,3 +161,27 @@ assert_type(f8.__ceil__(), int)
 assert_type(f8.__floor__(), int)
 
 assert_type(i8.is_integer(), Literal[True])
+
+assert_type(O.real, np.object_)
+assert_type(O.imag, np.object_)
+assert_type(int(O), int)
+assert_type(float(O), float)
+assert_type(complex(O), complex)
+
+# These fail fail because of a mypy __new__ bug:
+# https://github.com/python/mypy/issues/15182
+# According to the typing spec, the following statements are valid, see
+# https://typing.readthedocs.io/en/latest/spec/constructors.html#new-method
+
+# assert_type(np.object_(), None)
+# assert_type(np.object_(None), None)
+# assert_type(np.object_(array_nd), np.ndarray[Any, np.dtype[np.object_]])
+# assert_type(np.object_([]), npt.NDArray[np.object_])
+# assert_type(np.object_(()), npt.NDArray[np.object_])
+# assert_type(np.object_(range(4)), npt.NDArray[np.object_])
+# assert_type(np.object_(+42), int)
+# assert_type(np.object_(1 / 137), float)
+# assert_type(np.object_('Developers! ' * (1 << 6)), str)
+# assert_type(np.object_(object()), object)
+# assert_type(np.object_({False, True, NotADirectoryError}), set[Any])
+# assert_type(np.object_({'spam': 'food', 'ham': 'food'}), dict[str, str])