Descriptor Objects

"Descriptors" are objects that describe some attribute of an object. They are found in the dictionary of type objects.

Create a new get-set descriptor for extension type type from the PyGetSetDef structure getset.

Get-set descriptors expose attributes implemented by C getter and setter functions rather than stored directly in the instance. This is the same kind of descriptor created for entries in ~PyTypeObject.tp_getset, and it appears in Python as a types.GetSetDescriptorType object.

On success, return a strong reference to the descriptor. Return NULL with an exception set on failure.

Create a new member descriptor for extension type type from the PyMemberDef structure member.

Member descriptors expose fields in the type's C struct as Python attributes. This is the same kind of descriptor created for entries in ~PyTypeObject.tp_members, and it appears in Python as a types.MemberDescriptorType object.

On success, return a strong reference to the descriptor. Return NULL with an exception set on failure.

The type object for member descriptor objects created from PyMemberDef structures. These descriptors expose fields of a C struct as attributes on a type, and correspond to types.MemberDescriptorType objects in Python.

The type object for get/set descriptor objects created from PyGetSetDef structures. These descriptors implement attributes whose value is computed by C getter and setter functions, and are used for many built-in type attributes. They correspond to types.GetSetDescriptorType objects in Python.

Create a new method descriptor for extension type type from the PyMethodDef structure meth.

Method descriptors expose C functions as methods on a type. This is the same kind of descriptor created for entries in ~PyTypeObject.tp_methods, and it appears in Python as a types.MethodDescriptorType object.

On success, return a strong reference to the descriptor. Return NULL with an exception set on failure.

The type object for method descriptor objects created from PyMethodDef structures. These descriptors expose C functions as methods on a type, and correspond to types.MethodDescriptorType objects in Python.

The type object for wrapper descriptor objects created by PyDescr_NewWrapper and PyWrapper_New.

Wrapper descriptors are used internally to expose special methods such as __repr__ or __add__, which are implemented by type slots. The type is exposed in Python as types.WrapperDescriptorType.

Create a new wrapper descriptor of type PyWrapperDescr_Type.

This function is meant for internal use only; it and related API (struct wrapperbase and the PyWrapperFlag_KEYWORDS flag) are exposed publicly for backwards compatibility reasons.

See PyCMethod_New for wrapping a C function.

Create a new class method descriptor for extension type type from the PyMethodDef structure method.

Class method descriptors expose C methods that receive the class rather than an instance when accessed. This is the same kind of descriptor created for METH_CLASS entries in ~PyTypeObject.tp_methods, and it appears in Python as a types.ClassMethodDescriptorType object.

On success, return a strong reference to the descriptor. Return NULL with an exception set on failure.

Return non-zero if the descriptor object descr describes a data attribute, or 0 if it describes a method. descr must be a descriptor object; there is no error checking.

Create a new bound wrapper object from the wrapper descriptor d and the instance self.

This is the bound form of a wrapper descriptor created by PyDescr_NewWrapper. CPython creates these objects when a slot wrapper is accessed through an instance, and they appear in Python as types.MethodWrapperType objects.

On success, return a strong reference to the wrapper object. Return NULL with an exception set on failure.

Return a borrowed reference to the type that the descriptor descr belongs to. This is accessible as ~object.__objclass__ in Python.

descr must be a descriptor object created by one of the PyDescr_New* functions (an instance of PyMethodDescr_Type, PyClassMethodDescr_Type, PyMemberDescr_Type, PyGetSetDescr_Type, or PyWrapperDescr_Type). If the passed descriptor is not an instance of one of these types, the behavior is undefined.

Return the name of the descriptor descr as a borrowed reference to a str object. This is available as ~definition.__name__ in Python.

descr must be a descriptor object created by one of the PyDescr_New* functions. If not, the behavior is undefined.

This is a macro including the common fields for a descriptor object.

This was included in Python's C API by mistake; do not use it in extensions. For creating custom descriptor objects, create a class implementing the descriptor protocol (~PyTypeObject.tp_descr_get and ~PyTypeObject.tp_descr_set).

3.15

Built-in descriptors

The type object for property objects. This is the same object as property in the Python layer.

The type object for super objects. This is the same object as super in the Python layer.

The type of class method objects. This is the same object as classmethod in the Python layer.

The type object for C-level class method descriptor objects. This is the type of the descriptors created for classmethod defined in C extension types, and corresponds to types.ClassMethodDescriptorType objects in Python.

Create a new classmethod object wrapping callable. callable must be a callable object and must not be NULL.

On success, this function returns a strong reference to a new class method descriptor. On failure, this function returns NULL with an exception set.

The type of static method objects. This is the same object as staticmethod in the Python layer.

Create a new staticmethod object wrapping callable. callable must be a callable object and must not be NULL.

On success, this function returns a strong reference to a new static method descriptor. On failure, this function returns NULL with an exception set.