약한 참조 객체

파이썬은 약한 참조를 1급 객체로 지원합니다. 약한 참조를 직접 구현하는 두 가지 구체적인 객체 형이 있습니다. 첫 번째는 간단한 참조 객체이며, 두 번째는 가능한 한 원래 객체의 프락시 역할을 합니다.

int PyWeakref_Check(PyObject *ob)

ob가 참조 객체나 프락시 객체면 0이 아닌 값을 반환합니다. 이 함수는 항상 성공합니다.

int PyWeakref_CheckRef(PyObject *ob)

Return non-zero if ob is a reference object or a subclass of the reference type. This function always succeeds.

int PyWeakref_CheckRefExact(PyObject *ob)

Return non-zero if ob is a reference object, but not a subclass of the reference type. This function always succeeds.

int PyWeakref_CheckProxy(PyObject *ob)

ob가 프락시 객체면 0이 아닌 값을 반환합니다. 이 함수는 항상 성공합니다.

PyObject *PyWeakref_NewRef(PyObject *ob, PyObject *callback)

반환값: 새 참조. Part of the 안정 ABI.

Return a weak reference object for the object ob. This will always return a new reference, but is not guaranteed to create a new object; an existing reference object may be returned. The second parameter, callback, can be a callable object that receives notification when ob is garbage collected; it should accept a single parameter, which will be the weak reference object itself. callback may also be None or NULL. If ob is not a weakly referenceable object, or if callback is not callable, None, or NULL, this will raise TypeError and return NULL.

버전 3.16.0a0 (unreleased)에서 변경: Raise TypeError if callback is not callable, None, or NULL.

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PyType_SUPPORTS_WEAKREFS() for checking if ob is weakly referenceable.

PyObject *PyWeakref_NewProxy(PyObject *ob, PyObject *callback)

반환값: 새 참조. Part of the 안정 ABI.

Return a weak reference proxy object for the object ob. This will always return a new reference, but is not guaranteed to create a new object; an existing proxy object may be returned. The second parameter, callback, can be a callable object that receives notification when ob is garbage collected; it should accept a single parameter, which will be the weak reference object itself. callback may also be None or NULL. If ob is not a weakly referenceable object, or if callback is not callable, NULL, this will raise TypeError and return NULL.

버전 3.16.0a0 (unreleased)에서 변경: Raise TypeError if callback is not callable, None, or NULL.

더 보기

PyType_SUPPORTS_WEAKREFS() for checking if ob is weakly referenceable.

int PyWeakref_GetRef(PyObject *ref, PyObject **pobj)

Part of the 안정 ABI 버전 3.13 이후로.

Get a strong reference to the referenced object from a weak reference, ref, into *pobj.

• On success, set *pobj to a new strong reference to the referenced object and return 1.

• If the reference is dead, set *pobj to NULL and return 0.

• On error, raise an exception and return -1.

Added in version 3.13.

int PyWeakref_IsDead(PyObject *ref)

Test if the weak reference ref is dead. Returns 1 if the reference is dead, 0 if it is alive, and -1 with an error set if ref is not a weak reference object.

Added in version 3.14.

void PyObject_ClearWeakRefs(PyObject *object)

Part of the 안정 ABI.

This function is called by the tp_dealloc handler to clear weak references.

This iterates through the weak references for object and calls callbacks for those references which have one. It returns when all callbacks have been attempted.

void PyUnstable_Object_ClearWeakRefsNoCallbacks(PyObject *object)

이것은 불안정 API. It may change without warning in minor releases.

Clears the weakrefs for object without calling the callbacks.

This function is called by the tp_dealloc handler for types with finalizers (i.e., __del__()). The handler for those objects first calls PyObject_ClearWeakRefs() to clear weakrefs and call their callbacks, then the finalizer, and finally this function to clear any weakrefs that may have been created by the finalizer.

In most circumstances, it’s more appropriate to use PyObject_ClearWeakRefs() to clear weakrefs instead of this function.

Added in version 3.13.