# Object Protocol

PyObject *Py_GetConstant(unsigned int constant_id)
  Część stabilnego ABI od wersji 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 | Wartość | 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.

  Added in version 3.13.

  Szczegół implementacyjny CPythona: In CPython, all of these constants are immortal.

PyObject *Py_GetConstantBorrowed(unsigned int constant_id)
  Część stabilnego ABI od wersji 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.

  Added in version 3.13.

PyObject *Py_NotImplemented

  The `NotImplemented` singleton, used to signal that an operation is not implemented for the given type combination.

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 function would 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, const char *attr_name)
  Część stabilnego ABI od wersji 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`.

  Added in version 3.13.

int PyObject_HasAttrStringWithError(PyObject *o, const char *attr_name)
  Część stabilnego ABI od wersji 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*.

  Added in version 3.13.

int PyObject_HasAttr(PyObject *o, PyObject *attr_name)
  Część stabilnego ABI.

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

  Informacja

  Exceptions that occur when this calls `__getattr__()` and `__getattribute__()` methods are silently ignored. For proper error handling, use `PyObject_HasAttrWithError()`, `PyObject_GetOptionalAttr()` or `PyObject_GetAttr()` instead.

int PyObject_HasAttrString(PyObject *o, const char *attr_name)
  Część stabilnego ABI.

  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*.

  Informacja

  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)
  Wartość zwracana: nowa referencja. Część stabilnego ABI.

  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)
  Wartość zwracana: nowa referencja. Część stabilnego ABI.

  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);
  Część stabilnego ABI od wersji 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`.

  Added in version 3.13.

int PyObject_GetOptionalAttrString(PyObject *obj, const char *attr_name, PyObject **result);
  Część stabilnego ABI od wersji 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*.

  Added in version 3.13.

PyObject *PyObject_GenericGetAttr(PyObject *o, PyObject *name)
  Wartość zwracana: nowa referencja. Część stabilnego ABI.

  Generic attribute getter function that is meant to be put into a type object’s `tp_getattro` slot. It looks for a descriptor in the dictionary of classes in the object’s MRO as well as an attribute in the object’s `__dict__` (if present). As outlined in Implementing Descriptors, data descriptors take preference over instance attributes, while non-data descriptors don’t. Otherwise, an `AttributeError` is raised.

int PyObject_SetAttr(PyObject *o, PyObject *attr_name, PyObject *v)
  Część stabilnego ABI.

  Set the value of the attribute named attr_name, for object o, 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.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)
  Część stabilnego ABI.

  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)
  Część stabilnego ABI.

  Generic attribute setter and deleter function that is meant to be put into a type object’s `tp_setattro` slot. It looks for a data descriptor in the dictionary of classes in the object’s MRO, and if found it takes preference over setting or deleting the attribute in the instance dictionary. Otherwise, the attribute is set or deleted in the object’s `__dict__` (if present). On success, `0` is returned, otherwise an `AttributeError` is raised and `-1` is returned.

int PyObject_DelAttr(PyObject *o, PyObject *attr_name)
  Część stabilnego ABI od wersji 3.13.

  Delete attribute named attr_name, for object o. Returns `-1` on failure. This is the equivalent of the Python statement `del o.attr_name`.

int PyObject_DelAttrString(PyObject *o, const char *attr_name)
  Część stabilnego ABI od wersji 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)
  Wartość zwracana: nowa referencja. Część stabilnego ABI od wersji 3.10.

  A generic implementation for the getter of a `__dict__` descriptor. It creates the dictionary if necessary.

  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.

  Added in version 3.3.

int PyObject_GenericSetDict(PyObject *o, PyObject *value, void *context)
  Część stabilnego ABI od wersji 3.7.

  A generic implementation for the setter of a `__dict__` descriptor. This implementation does not allow the dictionary to be deleted.

  Added in 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)
  Wartość zwracana: nowa referencja. Część stabilnego ABI.

  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)
  Część stabilnego ABI.

  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.

Informacja

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)
  Część stabilnego ABI.

  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)
  Wartość zwracana: nowa referencja. Część stabilnego ABI.

  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.

  Zmienione w wersji 3.4: This function now includes a debug assertion to help ensure that it does not silently discard an active exception.

PyObject *PyObject_ASCII(PyObject *o)
  Wartość zwracana: nowa referencja. Część stabilnego ABI.

  As `PyObject_Repr()`, compute a string representation of object o, but escape the non-ASCII characters in the string returned by `PyObject_Repr()` with `\x`, `\u` or `\U` escapes. This generates a string similar to that returned by `PyObject_Repr()` in Python 2. Called by the `ascii()` built-in function.

PyObject *PyObject_Str(PyObject *o)
  Wartość zwracana: nowa referencja. Część stabilnego ABI.

  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.

  Zmienione w wersji 3.4: This function now includes a debug assertion to help ensure that it does not silently discard an active exception.

PyObject *PyObject_Bytes(PyObject *o)
  Wartość zwracana: nowa referencja. Część stabilnego ABI.

  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)
  Część stabilnego ABI.

  Return `1` if the class derived is identical to or derived from the class cls, otherwise return `0`. In case of an error, return `-1`.

  If cls is a tuple, the check will be done against every entry in cls. The result will be `1` when at least one of the checks returns `1`, otherwise it will be `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)
  Część stabilnego ABI.

  Return `1` if inst is an instance of the class cls or a subclass of cls, or `0` if not. On error, returns `-1` and sets an exception.

  If cls is a tuple, the check will be done against every entry in cls. The result will be `1` when at least one of the checks returns `1`, otherwise it will be `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)
  Część stabilnego ABI.

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

  Zmienione w wersji 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)
  Część stabilnego ABI.

  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)
  Część stabilnego ABI.

  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)
  Część stabilnego ABI.

  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)
  Wartość zwracana: nowa referencja. Część stabilnego ABI.

  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)
  Część stabilnego ABI.

  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)`.

  Added in version 3.4.

PyObject *PyObject_GetItem(PyObject *o, PyObject *key)
  Wartość zwracana: nowa referencja. Część stabilnego ABI.

  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)
  Część stabilnego ABI.

  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)
  Część stabilnego ABI.

  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]`.

PyObject *PyObject_Dir(PyObject *o)
  Wartość zwracana: nowa referencja. Część stabilnego ABI.

  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)
  Wartość zwracana: nowa referencja. Część stabilnego ABI.

  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_GetAIter(PyObject *o)
  Wartość zwracana: nowa referencja. Część stabilnego ABI od wersji 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.

  Added in version 3.10.

void *PyObject_GetTypeData(PyObject *o, PyTypeObject *cls)
  Część stabilnego ABI od wersji 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`.

  Added in version 3.12.

Py_ssize_t PyType_GetTypeDataSize(PyTypeObject *cls)
  Część stabilnego ABI od wersji 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.

  Added in 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.

  Added in 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.

  Added in version 3.13.

void PyObject_ClearManagedDict(PyObject *obj)

  Clear 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.

  Added in version 3.13.