Objects for Type Hinting¶
Various built-in types for type hinting are provided.  Currently,
two types exist – GenericAlias and
Union.  Only GenericAlias is exposed to C.
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PyObject *Py_GenericAlias(PyObject *origin, PyObject *args)¶
-  Part of the Stable ABI since version 3.9.Create a GenericAlias object. Equivalent to calling the Python class types.GenericAlias. The origin and args arguments set theGenericAlias‘s__origin__and__args__attributes respectively. origin should be a PyTypeObject*, and args can be a PyTupleObject* or anyPyObject*. If args passed is not a tuple, a 1-tuple is automatically constructed and__args__is set to(args,). Minimal checking is done for the arguments, so the function will succeed even if origin is not a type. TheGenericAlias‘s__parameters__attribute is constructed lazily from__args__. On failure, an exception is raised andNULLis returned.Here’s an example of how to make an extension type generic: ... static PyMethodDef my_obj_methods[] = { // Other methods. ... {"__class_getitem__", Py_GenericAlias, METH_O|METH_CLASS, "See PEP 585"} ... } See also The data model method __class_getitem__().Added in version 3.9. 
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PyTypeObject Py_GenericAliasType¶
-  Part of the Stable ABI since version 3.9.The C type of the object returned by Py_GenericAlias(). Equivalent totypes.GenericAliasin Python.Added in version 3.9.