Objets à références faibles

Python gère les références faibles comme des objets de première classe. Il existe deux types d'objets spécifiques qui implémentent directement les références faibles. Le premier est un objet de référence simple, et le second agit autant que possible comme un mandataire vers l'objet original.

int PyWeakref_Check(PyObject *ob)

Return non-zero if ob is either a reference or proxy object. This function always succeeds.

int PyWeakref_CheckRef(PyObject *ob)

Return non-zero if ob is a reference object. This function always succeeds.

int PyWeakref_CheckProxy(PyObject *ob)

Return non-zero if ob is a proxy object. This function always succeeds.

PyObject *PyWeakref_NewRef(PyObject *ob, PyObject *callback)
Valeur de retour : nouvelle référence. Part of the Stable 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 return NULL and raise TypeError.

PyObject *PyWeakref_NewProxy(PyObject *ob, PyObject *callback)
Valeur de retour : nouvelle référence. Part of the Stable 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, None, or NULL, this will return NULL and raise TypeError.

int PyWeakref_GetRef(PyObject *ref, PyObject **pobj)
Part of the Stable ABI since version 3.13.

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.

PyObject *PyWeakref_GetObject(PyObject *ref)
Valeur de retour : référence empruntée. Part of the Stable ABI.

Return a borrowed reference to the referenced object from a weak reference, ref. If the referent is no longer live, returns Py_None.

Note

This function returns a borrowed reference to the referenced object. This means that you should always call Py_INCREF() on the object except when it cannot be destroyed before the last usage of the borrowed reference.

Obsolète depuis la version 3.13, sera supprimé dans la version 3.15: Use PyWeakref_GetRef() instead.

PyObject *PyWeakref_GET_OBJECT(PyObject *ref)
Valeur de retour : référence empruntée.

Similar to PyWeakref_GetObject(), but does no error checking.

Obsolète depuis la version 3.13, sera supprimé dans la version 3.15: Use PyWeakref_GetRef() instead.

void PyObject_ClearWeakRefs(PyObject *object)
Part of the Stable 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.