# Protocole Objet

PyObject *Py_GetConstant(unsigned int constant_id)
  Fait partie de l' ABI stable depuis la version 3.13.

  Get a strong reference to a constant.

  Set an exception and return `NULL` if constant_id is invalid.

  constant_id must be one of these constant identifiers:

  Constant Identifier | Valeur | Returned object
  --- | --- | ---
  Py_CONSTANT_NONE | `0` | `None`
  Py_CONSTANT_FALSE | `1` | `False`
  Py_CONSTANT_TRUE | `2` | `True`
  Py_CONSTANT_ELLIPSIS | `3` | `Ellipsis`
  Py_CONSTANT_NOT_IMPLEMENTED | `4` | `NotImplemented`
  Py_CONSTANT_ZERO | `5` | `0`
  Py_CONSTANT_ONE | `6` | `1`
  Py_CONSTANT_EMPTY_STR | `7` | `''`
  Py_CONSTANT_EMPTY_BYTES | `8` | `b''`
  Py_CONSTANT_EMPTY_TUPLE | `9` | `()`

  Numeric values are only given for projects which cannot use the constant identifiers.

  Ajouté dans la version 3.13.

  Particularité de l'implémentation CPython : In CPython, all of these constants are immortal.

PyObject *Py_GetConstantBorrowed(unsigned int constant_id)
  Fait partie de l' ABI stable depuis la version 3.13.

  Similar to `Py_GetConstant()`, but return a borrowed reference.

  This function is primarily intended for backwards compatibility: using `Py_GetConstant()` is recommended for new code.

  The reference is borrowed from the interpreter, and is valid until the interpreter finalization.

  Ajouté dans la version 3.13.

PyObject *Py_NotImplemented

  Le singleton `NotImplemented`, utilisé pour signaler qu'une opération n'est pas implémentée pour la combinaison de types en question.

Py_RETURN_NOTIMPLEMENTED

  Properly handle returning `Py_NotImplemented` from within a C function (that is, create a new strong reference to `NotImplemented` and return it).

Py_PRINT_RAW

  Flag to be used with multiple functions that print the object (like `PyObject_Print()` and `PyFile_WriteObject()`). If passed, these functions use the `str()` of the object instead of the `repr()`.

int PyObject_Print(PyObject *o, FILE *fp, int flags)

  Print an object o, on file fp. Returns `-1` on error. The flags argument is used to enable certain printing options. The only option currently supported is `Py_PRINT_RAW`; if given, the `str()` of the object is written instead of the `repr()`.

int PyObject_HasAttrWithError(PyObject *o, PyObject *attr_name)
  Fait partie de l' ABI stable depuis la version 3.13.

  Returns `1` if o has the attribute attr_name, and `0` otherwise. This is equivalent to the Python expression `hasattr(o, attr_name)`. On failure, return `-1`.

  Ajouté dans la version 3.13.

int PyObject_HasAttrStringWithError(PyObject *o, const char *attr_name)
  Fait partie de l' ABI stable depuis la version 3.13.

  This is the same as `PyObject_HasAttrWithError()`, but attr_name is specified as a const char* UTF-8 encoded bytes string, rather than a PyObject*.

  Ajouté dans la version 3.13.

int PyObject_HasAttr(PyObject *o, PyObject *attr_name)
  Fait partie de l' ABI stable.

  Returns `1` if o has the attribute attr_name, and `0` otherwise. This function always succeeds.

  Note

  Exceptions that occur when this calls `__getattr__()` and `__getattribute__()` methods aren't propagated, but instead given to `sys.unraisablehook()`. For proper error handling, use `PyObject_HasAttrWithError()`, `PyObject_GetOptionalAttr()` or `PyObject_GetAttr()` instead.

int PyObject_HasAttrString(PyObject *o, const char *attr_name)
  Fait partie de l' ABI stable.

  This is the same as `PyObject_HasAttr()`, but attr_name is specified as a const char* UTF-8 encoded bytes string, rather than a PyObject*.

  Note

  Exceptions that occur when this calls `__getattr__()` and `__getattribute__()` methods or while creating the temporary `str` object are silently ignored. For proper error handling, use `PyObject_HasAttrStringWithError()`, `PyObject_GetOptionalAttrString()` or `PyObject_GetAttrString()` instead.

PyObject *PyObject_GetAttr(PyObject *o, PyObject *attr_name)
  Valeur de retour : nouvelle référence. Fait partie de l' ABI stable.

  Retrieve an attribute named attr_name from object o. Returns the attribute value on success, or `NULL` on failure. This is the equivalent of the Python expression `o.attr_name`.

  If the missing attribute should not be treated as a failure, you can use `PyObject_GetOptionalAttr()` instead.

PyObject *PyObject_GetAttrString(PyObject *o, const char *attr_name)
  Valeur de retour : nouvelle référence. Fait partie de l' ABI stable.

  This is the same as `PyObject_GetAttr()`, but attr_name is specified as a const char* UTF-8 encoded bytes string, rather than a PyObject*.

  If the missing attribute should not be treated as a failure, you can use `PyObject_GetOptionalAttrString()` instead.

int PyObject_GetOptionalAttr(PyObject *obj, PyObject *attr_name, PyObject **result);
  Fait partie de l' ABI stable depuis la version 3.13.

  Variant of `PyObject_GetAttr()` which doesn't raise `AttributeError` if the attribute is not found.

  If the attribute is found, return `1` and set *result to a new strong reference to the attribute. If the attribute is not found, return `0` and set *result to `NULL`; the `AttributeError` is silenced. If an error other than `AttributeError` is raised, return `-1` and set *result to `NULL`.

  Ajouté dans la version 3.13.

int PyObject_GetOptionalAttrString(PyObject *obj, const char *attr_name, PyObject **result);
  Fait partie de l' ABI stable depuis la version 3.13.

  This is the same as `PyObject_GetOptionalAttr()`, but attr_name is specified as a const char* UTF-8 encoded bytes string, rather than a PyObject*.

  Ajouté dans la version 3.13.

PyObject *PyObject_GenericGetAttr(PyObject *o, PyObject *name)
  Valeur de retour : nouvelle référence. Fait partie de l' ABI stable.

  Accesseur d'attribut générique destiné à être mis dans le slot `tp_getattro` d'un objet type. Recherche un descripteur dans le dictionnaire de classes du MRO de l'objet ainsi qu'un attribut dans le `__dict__` de l'objet (si présent). Comme défini dans Implémentation de descripteurs, les descripteurs de données sont prioritaires sur les attributs d'instance, contrairement aux autres descripteurs. Sinon, une `AttributeError` est levée.

int PyObject_SetAttr(PyObject *o, PyObject *attr_name, PyObject *v)
  Fait partie de l' ABI stable.

  Définit la valeur de l'attribut nommé attr_name, pour l'objet o, à la valeur v. Lève une exception et renvoie `-1` en cas d'échec ; renvoie `0` en cas de succès. Ceci est équivalent à l'instruction Python `o.attr_name = v`.

  If v is `NULL`, the attribute is deleted. This behaviour is deprecated in favour of using `PyObject_DelAttr()`, but there are currently no plans to remove it.

int PyObject_SetAttrString(PyObject *o, const char *attr_name, PyObject *v)
  Fait partie de l' ABI stable.

  This is the same as `PyObject_SetAttr()`, but attr_name is specified as a const char* UTF-8 encoded bytes string, rather than a PyObject*.

  If v is `NULL`, the attribute is deleted, but this feature is deprecated in favour of using `PyObject_DelAttrString()`.

  The number of different attribute names passed to this function should be kept small, usually by using a statically allocated string as attr_name. For attribute names that aren't known at compile time, prefer calling `PyUnicode_FromString()` and `PyObject_SetAttr()` directly. For more details, see `PyUnicode_InternFromString()`, which may be used internally to create a key object.

int PyObject_GenericSetAttr(PyObject *o, PyObject *name, PyObject *value)
  Fait partie de l' ABI stable.

  Accesseur et suppresseur générique d'attributs qui est fait pour être mis dans le `tp_setattro` d'un objet type. Il cherche un descripteur de données dans le dictionnaire de classes dans le MRO de l'objet et, si ce descripteur est trouvé, c'est lui qui est utilisé de préférence pour la suppression et la définition de l'attribut dans le dictionnaire d'instance. Sinon, l'attribut est défini ou supprimé dans le `__dict__` de l'objet (si présent). En cas de succès, `0` est renvoyé, sinon une `AttributeError` est levée et `-1` est renvoyé.

int PyObject_DelAttr(PyObject *o, PyObject *attr_name)
  Fait partie de l' ABI stable depuis la version 3.13.

  Supprime l'attribut nommé attr_name, pour l'objet o. Renvoie `-1` en cas d'échec. Ceci est l'équivalent de l'expression Python `del o.attr_name`.

int PyObject_DelAttrString(PyObject *o, const char *attr_name)
  Fait partie de l' ABI stable depuis la version 3.13.

  This is the same as `PyObject_DelAttr()`, but attr_name is specified as a const char* UTF-8 encoded bytes string, rather than a PyObject*.

  The number of different attribute names passed to this function should be kept small, usually by using a statically allocated string as attr_name. For attribute names that aren't known at compile time, prefer calling `PyUnicode_FromString()` and `PyObject_DelAttr()` directly. For more details, see `PyUnicode_InternFromString()`, which may be used internally to create a key object for lookup.

PyObject *PyObject_GenericGetDict(PyObject *o, void *context)
  Valeur de retour : nouvelle référence. Fait partie de l' ABI stable depuis la version 3.10.

  Une implémentation générique de l'accesseur d'un descripteur d'un `__dict__`. Crée le dictionnaire si nécessaire.

  This function may also be called to get the `__dict__` of the object o. Pass `NULL` for context when calling it. Since this function may need to allocate memory for the dictionary, it may be more efficient to call `PyObject_GetAttr()` when accessing an attribute on the object.

  On failure, returns `NULL` with an exception set.

  Ajouté dans la version 3.3.

int PyObject_GenericSetDict(PyObject *o, PyObject *value, void *context)
  Fait partie de l' ABI stable depuis la version 3.7.

  Une implémentation générique du mutateur d'un descripteur de `__dict__`. Cette implémentation n'autorise pas la suppression du dictionnaire.

  Ajouté dans la version 3.3.

PyObject **_PyObject_GetDictPtr(PyObject *obj)

  Return a pointer to `__dict__` of the object obj. If there is no `__dict__`, return `NULL` without setting an exception.

  This function may need to allocate memory for the dictionary, so it may be more efficient to call `PyObject_GetAttr()` when accessing an attribute on the object.

PyObject *PyObject_RichCompare(PyObject *o1, PyObject *o2, int opid)
  Valeur de retour : nouvelle référence. Fait partie de l' ABI stable.

  Compare the values of o1 and o2 using the operation specified by opid, which must be one of `Py_LT`, `Py_LE`, `Py_EQ`, `Py_NE`, `Py_GT`, or `Py_GE`, corresponding to `<`, `<=`, `==`, `!=`, `>`, or `>=` respectively. This is the equivalent of the Python expression `o1 op o2`, where `op` is the operator corresponding to opid. Returns the value of the comparison on success, or `NULL` on failure.

int PyObject_RichCompareBool(PyObject *o1, PyObject *o2, int opid)
  Fait partie de l' ABI stable.

  Compare the values of o1 and o2 using the operation specified by opid, like `PyObject_RichCompare()`, but returns `-1` on error, `0` if the result is false, `1` otherwise.

Note

If o1 and o2 are the same object, `PyObject_RichCompareBool()` will always return `1` for `Py_EQ` and `0` for `Py_NE`.

PyObject *PyObject_Format(PyObject *obj, PyObject *format_spec)
  Fait partie de l' ABI stable.

  Format obj using format_spec. This is equivalent to the Python expression `format(obj, format_spec)`.

  format_spec may be `NULL`. In this case the call is equivalent to `format(obj)`. Returns the formatted string on success, `NULL` on failure.

PyObject *PyObject_Repr(PyObject *o)
  Valeur de retour : nouvelle référence. Fait partie de l' ABI stable.

  Compute a string representation of object o. Returns the string representation on success, `NULL` on failure. This is the equivalent of the Python expression `repr(o)`. Called by the `repr()` built-in function.

  Modifié dans la version 3.4: Cette fonction inclut maintenant une assertion de débogage afin d'assurer qu'elle ne passe pas sous silence une exception active.

PyObject *PyObject_ASCII(PyObject *o)
  Valeur de retour : nouvelle référence. Fait partie de l' ABI stable.

  Comme `PyObject_Repr()`, calcule une représentation en chaîne de caractères de l'objet o, mais échappe les caractères non ASCII dans la chaîne de caractères renvoyée par `PyObject_Repr()` avec' `\x`, `\u` ou `\U`. Cela génère une chaîne de caractères similaire à celle renvoyée par `PyObject_Repr()` en Python 2. Appelée par la fonction native `ascii()`.

PyObject *PyObject_Str(PyObject *o)
  Valeur de retour : nouvelle référence. Fait partie de l' ABI stable.

  Compute a string representation of object o. Returns the string representation on success, `NULL` on failure. This is the equivalent of the Python expression `str(o)`. Called by the `str()` built-in function and, therefore, by the `print()` function.

  Modifié dans la version 3.4: Cette fonction inclut maintenant une assertion de débogage afin d'assurer qu'elle ne passe pas sous silence une exception active.

PyObject *PyObject_Bytes(PyObject *o)
  Valeur de retour : nouvelle référence. Fait partie de l' ABI stable.

  Compute a bytes representation of object o. `NULL` is returned on failure and a bytes object on success. This is equivalent to the Python expression `bytes(o)`, when o is not an integer. Unlike `bytes(o)`, a TypeError is raised when o is an integer instead of a zero-initialized bytes object.

int PyObject_IsSubclass(PyObject *derived, PyObject *cls)
  Fait partie de l' ABI stable.

  Renvoie `1` si la classe derived est identique à ou dérivée de la classe cls, renvoie `0` sinon. En cas d'erreur, renvoie `-1`.

  Si cls est un n-uplet, la vérification est menée sur chaque entrée de cls. Le résultat sera `1` quand au moins une des vérifications renvoie `1`, sinon ce sera `0`.

  If cls has a `__subclasscheck__()` method, it will be called to determine the subclass status as described in PEP 3119. Otherwise, derived is a subclass of cls if it is a direct or indirect subclass, i.e. contained in `cls.__mro__`.

  Normally only class objects, i.e. instances of `type` or a derived class, are considered classes. However, objects can override this by having a `__bases__` attribute (which must be a tuple of base classes).

int PyObject_IsInstance(PyObject *inst, PyObject *cls)
  Fait partie de l' ABI stable.

  Renvoie `1` si inst est une instance de la classe cls ou une sous-classe de cls, ou `0` sinon. En cas d'erreur, renvoie `-1` et initialise une exception.

  Si cls est un n-uplet, la vérification est menée sur chaque entrée de cls. Le résultat sera `1` quand au moins une des vérifications renvoie `1`, sinon ce sera `0`.

  If cls has a `__instancecheck__()` method, it will be called to determine the subclass status as described in PEP 3119. Otherwise, inst is an instance of cls if its class is a subclass of cls.

  An instance inst can override what is considered its class by having a `__class__` attribute.

  An object cls can override if it is considered a class, and what its base classes are, by having a `__bases__` attribute (which must be a tuple of base classes).

Py_hash_t PyObject_Hash(PyObject *o)
  Fait partie de l' ABI stable.

  Compute and return the hash value of an object o. On failure, return `-1`. This is the equivalent of the Python expression `hash(o)`.

  Modifié dans la version 3.2: The return type is now Py_hash_t. This is a signed integer the same size as `Py_ssize_t`.

Py_hash_t PyObject_HashNotImplemented(PyObject *o)
  Fait partie de l' ABI stable.

  Set a `TypeError` indicating that `type(o)` is not hashable and return `-1`. This function receives special treatment when stored in a `tp_hash` slot, allowing a type to explicitly indicate to the interpreter that it is not hashable.

int PyObject_IsTrue(PyObject *o)
  Fait partie de l' ABI stable.

  Returns `1` if the object o is considered to be true, and `0` otherwise. This is equivalent to the Python expression `not not o`. On failure, return `-1`.

int PyObject_Not(PyObject *o)
  Fait partie de l' ABI stable.

  Returns `0` if the object o is considered to be true, and `1` otherwise. This is equivalent to the Python expression `not o`. On failure, return `-1`.

PyObject *PyObject_Type(PyObject *o)
  Valeur de retour : nouvelle référence. Fait partie de l' ABI stable.

  When o is non-`NULL`, returns a type object corresponding to the object type of object o. On failure, raises `SystemError` and returns `NULL`. This is equivalent to the Python expression `type(o)`. This function creates a new strong reference to the return value. There's really no reason to use this function instead of the `Py_TYPE()` function, which returns a pointer of type PyTypeObject*, except when a new strong reference is needed.

int PyObject_TypeCheck(PyObject *o, PyTypeObject *type)

  Return non-zero if the object o is of type type or a subtype of type, and `0` otherwise. Both parameters must be non-`NULL`.

Py_ssize_t PyObject_Size(PyObject *o)
Py_ssize_t PyObject_Length(PyObject *o)
  Fait partie de l' ABI stable.

  Return the length of object o. If the object o provides either the sequence and mapping protocols, the sequence length is returned. On error, `-1` is returned. This is the equivalent to the Python expression `len(o)`.

Py_ssize_t PyObject_LengthHint(PyObject *o, Py_ssize_t defaultvalue)

  Return an estimated length for the object o. First try to return its actual length, then an estimate using `__length_hint__()`, and finally return the default value. On error return `-1`. This is the equivalent to the Python expression `operator.length_hint(o, defaultvalue)`.

  Ajouté dans la version 3.4.

PyObject *PyObject_GetItem(PyObject *o, PyObject *key)
  Valeur de retour : nouvelle référence. Fait partie de l' ABI stable.

  Return element of o corresponding to the object key or `NULL` on failure. This is the equivalent of the Python expression `o[key]`.

int PyObject_SetItem(PyObject *o, PyObject *key, PyObject *v)
  Fait partie de l' ABI stable.

  Map the object key to the value v. Raise an exception and return `-1` on failure; return `0` on success. This is the equivalent of the Python statement `o[key] = v`. This function does not steal a reference to v.

int PyObject_DelItem(PyObject *o, PyObject *key)
  Fait partie de l' ABI stable.

  Remove the mapping for the object key from the object o. Return `-1` on failure. This is equivalent to the Python statement `del o[key]`.

int PyObject_DelItemString(PyObject *o, const char *key)
  Fait partie de l' ABI stable.

  This is the same as `PyObject_DelItem()`, but key is specified as a const char* UTF-8 encoded bytes string, rather than a PyObject*.

PyObject *PyObject_Dir(PyObject *o)
  Valeur de retour : nouvelle référence. Fait partie de l' ABI stable.

  This is equivalent to the Python expression `dir(o)`, returning a (possibly empty) list of strings appropriate for the object argument, or `NULL` if there was an error. If the argument is `NULL`, this is like the Python `dir()`, returning the names of the current locals; in this case, if no execution frame is active then `NULL` is returned but `PyErr_Occurred()` will return false.

PyObject *PyObject_GetIter(PyObject *o)
  Valeur de retour : nouvelle référence. Fait partie de l' ABI stable.

  This is equivalent to the Python expression `iter(o)`. It returns a new iterator for the object argument, or the object itself if the object is already an iterator. Raises `TypeError` and returns `NULL` if the object cannot be iterated.

PyObject *PyObject_SelfIter(PyObject *obj)
  Valeur de retour : nouvelle référence. Fait partie de l' ABI stable.

  This is equivalent to the Python `__iter__(self): return self` method. It is intended for iterator types, to be used in the `PyTypeObject.tp_iter` slot.

PyObject *PyObject_GetAIter(PyObject *o)
  Valeur de retour : nouvelle référence. Fait partie de l' ABI stable depuis la version 3.10.

  This is the equivalent to the Python expression `aiter(o)`. Takes an `AsyncIterable` object and returns an `AsyncIterator` for it. This is typically a new iterator but if the argument is an `AsyncIterator`, this returns itself. Raises `TypeError` and returns `NULL` if the object cannot be iterated.

  Ajouté dans la version 3.10.

void *PyObject_GetTypeData(PyObject *o, PyTypeObject *cls)
  Fait partie de l' ABI stable depuis la version 3.12.

  Get a pointer to subclass-specific data reserved for cls.

  The object o must be an instance of cls, and cls must have been created using negative `PyType_Spec.basicsize`. Python does not check this.

  On error, set an exception and return `NULL`.

  Ajouté dans la version 3.12.

Py_ssize_t PyType_GetTypeDataSize(PyTypeObject *cls)
  Fait partie de l' ABI stable depuis la version 3.12.

  Return the size of the instance memory space reserved for cls, i.e. the size of the memory `PyObject_GetTypeData()` returns.

  This may be larger than requested using `-PyType_Spec.basicsize`; it is safe to use this larger size (e.g. with `memset()`).

  The type cls must have been created using negative `PyType_Spec.basicsize`. Python does not check this.

  On error, set an exception and return a negative value.

  Ajouté dans la version 3.12.

void *PyObject_GetItemData(PyObject *o)

  Get a pointer to per-item data for a class with `Py_TPFLAGS_ITEMS_AT_END`.

  On error, set an exception and return `NULL`. `TypeError` is raised if o does not have `Py_TPFLAGS_ITEMS_AT_END` set.

  Ajouté dans la version 3.12.

int PyObject_VisitManagedDict(PyObject *obj, visitproc visit, void *arg)

  Visit the managed dictionary of obj.

  This function must only be called in a traverse function of the type which has the `Py_TPFLAGS_MANAGED_DICT` flag set.

  Ajouté dans la version 3.13.

void PyObject_ClearManagedDict(PyObject *obj)

  Clear the managed dictionary of obj.

  This function must only be called in a clear function of the type which has the `Py_TPFLAGS_MANAGED_DICT` flag set.

  Ajouté dans la version 3.13.

int PyUnstable_Object_EnableDeferredRefcount(PyObject *obj)
  Fait partie de l' API instable. Peut changer sans avertissement d'une version mineure à l'autre.

  Enable deferred reference counting on obj, if supported by the runtime. In the free-threaded build, this allows the interpreter to avoid reference count adjustments to obj, which may improve multi-threaded performance. The tradeoff is that obj will only be deallocated by the tracing garbage collector, and not when the interpreter no longer has any references to it.

  This function returns `1` if deferred reference counting is enabled on obj, and `0` if deferred reference counting is not supported or if the hint was ignored by the interpreter, such as when deferred reference counting is already enabled on obj. This function is thread-safe, and cannot fail.

  This function does nothing on builds with the GIL enabled, which do not support deferred reference counting. This also does nothing if obj is not an object tracked by the garbage collector (see `gc.is_tracked()` and `PyObject_GC_IsTracked()`).

  This function is intended to be used soon after obj is created, by the code that creates it, such as in the object's `tp_new` slot.

  Ajouté dans la version 3.14.

int PyUnstable_Object_IsUniqueReferencedTemporary(PyObject *obj)
  Fait partie de l' API instable. Peut changer sans avertissement d'une version mineure à l'autre.

  Check if obj is a unique temporary object. Returns `1` if obj is known to be a unique temporary object, and `0` otherwise. This function cannot fail, but the check is conservative, and may return `0` in some cases even if obj is a unique temporary object.

  If an object is a unique temporary, it is guaranteed that the current code has the only reference to the object. For arguments to C functions, this should be used instead of checking if the reference count is `1`. Starting with Python 3.14, the interpreter internally avoids some reference count modifications when loading objects onto the operands stack by borrowing references when possible, which means that a reference count of `1` by itself does not guarantee that a function argument uniquely referenced.

  In the example below, `my_func` is called with a unique temporary object as its argument:

      my_func([1, 2, 3])

  In the example below, `my_func` is not called with a unique temporary object as its argument, even if its refcount is `1`:

      my_list = [1, 2, 3]
      my_func(my_list)

  See also the function `Py_REFCNT()`.

  Ajouté dans la version 3.14.

int PyUnstable_IsImmortal(PyObject *obj)
  Fait partie de l' API instable. Peut changer sans avertissement d'une version mineure à l'autre.

  This function returns non-zero if obj is immortal, and zero otherwise. This function cannot fail.

  Note

  Objects that are immortal in one CPython version are not guaranteed to be immortal in another.

  Ajouté dans la version 3.14.

int PyUnstable_TryIncRef(PyObject *obj)
  Fait partie de l' API instable. Peut changer sans avertissement d'une version mineure à l'autre.

  Increments the reference count of obj if it is not zero. Returns `1` if the object's reference count was successfully incremented. Otherwise, this function returns `0`.

  `PyUnstable_EnableTryIncRef()` must have been called earlier on obj or this function may spuriously return `0` in the free-threaded build.

  This function is logically equivalent to the following C code, except that it behaves atomically in the free-threaded build:

      if (Py_REFCNT(op) > 0) {
         Py_INCREF(op);
         return 1;
      }
      return 0;

  This is intended as a building block for managing weak references without the overhead of a Python weak reference object.

  Typically, correct use of this function requires support from obj's deallocator (`tp_dealloc`). For example, the following sketch could be adapted to implement a "weakmap" that works like a `WeakValueDictionary` for a specific type:

      PyMutex mutex;

      PyObject *
      add_entry(weakmap_key_type *key, PyObject *value)
      {
          PyUnstable_EnableTryIncRef(value);
          weakmap_type weakmap = ...;
          PyMutex_Lock(&mutex);
          weakmap_add_entry(weakmap, key, value);
          PyMutex_Unlock(&mutex);
          Py_RETURN_NONE;
      }

      PyObject *
      get_value(weakmap_key_type *key)
      {
          weakmap_type weakmap = ...;
          PyMutex_Lock(&mutex);
          PyObject *result = weakmap_find(weakmap, key);
          if (PyUnstable_TryIncRef(result)) {
              // `result` is safe to use
              PyMutex_Unlock(&mutex);
              return result;
          }
          // if we get here, `result` is starting to be garbage-collected,
          // but has not been removed from the weakmap yet
          PyMutex_Unlock(&mutex);
          return NULL;
      }

      // tp_dealloc function for weakmap values
      void
      value_dealloc(PyObject *value)
      {
          weakmap_type weakmap = ...;
          PyMutex_Lock(&mutex);
          weakmap_remove_value(weakmap, value);

          ...
          PyMutex_Unlock(&mutex);
      }

  Ajouté dans la version 3.14.

void PyUnstable_EnableTryIncRef(PyObject *obj)
  Fait partie de l' API instable. Peut changer sans avertissement d'une version mineure à l'autre.

  Enables subsequent uses of `PyUnstable_TryIncRef()` on obj. The caller must hold a strong reference to obj when calling this.

  Ajouté dans la version 3.14.

int PyUnstable_Object_IsUniquelyReferenced(PyObject *op)
  Fait partie de l' API instable. Peut changer sans avertissement d'une version mineure à l'autre.

  Determine if op only has one reference.

  On GIL-enabled builds, this function is equivalent to Py_REFCNT(op) == 1.

  On a free-threaded build, this checks if op's reference count is equal to one and additionally checks if op is only used by this thread. Py_REFCNT(op) == 1 is not thread-safe on free-threaded builds; prefer this function.

  The caller must hold an attached thread state, despite the fact that this function doesn't call into the Python interpreter. This function cannot fail.

  Ajouté dans la version 3.14.