7.5.8 Weak Reference Objects
Python supports weak references as first-class objects. There are two specific
object types which directly implement weak references. The first is a simple reference object,
and the second acts as a proxy for the original object as much as it can.
-
- Return true if ob is either a reference or proxy object. New in version 2.2.
-
| int PyWeakref_CheckRef( |
ob) |
- Return true if ob is a reference object. New in
version 2.2.
-
| int PyWeakref_CheckProxy( |
ob) |
- Return true if ob is a proxy object. New in version
2.2.
-
| PyObject* PyWeakref_NewRef( |
PyObject *ob, PyObject *callback) |
-
Return value: New reference.
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
paramter, which will be the weak reference object itself. callback may also be None
or NULL. If ob is not a weakly-referencable object,
or if callback is not callable, None, or NULL,
this will return NULL and raise TypeError.
New in version 2.2.
-
| PyObject* PyWeakref_NewProxy( |
PyObject *ob, PyObject *callback) |
-
Return value: New reference.
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
paramter, which will be the weak reference object itself. callback may also be None
or NULL. If ob is not a weakly-referencable object,
or if callback is not callable, None, or NULL,
this will return NULL and raise TypeError.
New in version 2.2.
-
| PyObject* PyWeakref_GetObject( |
PyObject *ref) |
-
Return value: Borrowed reference.
Returns the referenced object from a weak reference, ref. If the referent is no
longer live, returns None. New in version 2.2.
-
| PyObject* PyWeakref_GET_OBJECT( |
PyObject *ref) |
-
Return value: Borrowed reference.
Similar to PyWeakref_GetObject(), but implemented as a macro
that does no error checking. New in version 2.2.
|
