MAINT: Directly use np.ndarray.__class_getitem__ for the definition of npt.NDArray

Author: BvB93

numpy/typing/_generic_alias.py

@@ -205,12 +205,9 @@ def __getattribute__(self, name: str) -> Any:
 
 ScalarType = TypeVar("ScalarType", bound=np.generic, covariant=True)
 
-if TYPE_CHECKING:
+if TYPE_CHECKING or sys.version_info >= (3, 9):
     _DType = np.dtype[ScalarType]
     NDArray = np.ndarray[Any, np.dtype[ScalarType]]
-elif sys.version_info >= (3, 9):
-    _DType = types.GenericAlias(np.dtype, (ScalarType,))
-    NDArray = types.GenericAlias(np.ndarray, (Any, _DType))
 else:
     _DType = _GenericAlias(np.dtype, (ScalarType,))
     NDArray = _GenericAlias(np.ndarray, (Any, _DType))