# 型オブジェクト

type PyTypeObject
  次に属します: Limited API (不透明な構造体として).

  組み込み型を記述する際に用いられる、オブジェクトを表す C 構造体です。

PyTypeObject PyType_Type
  次に属します: Stable ABI.

  型オブジェクト自身の型オブジェクトです。Python レイヤにおける `type` と同じオブジェクトです。

int PyType_Check(PyObject *o)

  Return non-zero if the object o is a type object, including instances of types derived from the standard type object. Return 0 in all other cases. This function always succeeds.

int PyType_CheckExact(PyObject *o)

  Return non-zero if the object o is a type object, but not a subtype of the standard type object. Return 0 in all other cases. This function always succeeds.

unsigned int PyType_ClearCache()
  次に属します: Stable ABI.

  内部の検索キャッシュをクリアします。現在のバージョンタグを返します。

unsigned long PyType_GetFlags(PyTypeObject *type)
  次に属します: Stable ABI.

  Return the `tp_flags` member of type. This function is primarily meant for use with `Py_LIMITED_API`; the individual flag bits are guaranteed to be stable across Python releases, but access to `tp_flags` itself is not part of the limited API.

  バージョン 3.2 で追加.

  バージョン 3.4 で変更: 返り値の型が `long` ではなく `unsigned long` になりました。

void PyType_Modified(PyTypeObject *type)
  次に属します: Stable ABI.

  内部の検索キャッシュを、その type とすべてのサブタイプに対して無効にします。この関数は type の属性や基底クラス列を変更したあとに手動で呼び出さなければなりません。

int PyType_HasFeature(PyTypeObject *o, int feature)

  Return non-zero if the type object o sets the feature feature. Type features are denoted by single bit flags.

int PyType_IS_GC(PyTypeObject *o)

  Return true if the type object includes support for the cycle detector; this tests the type flag `Py_TPFLAGS_HAVE_GC`.

int PyType_IsSubtype(PyTypeObject *a, PyTypeObject *b)
  次に属します: Stable ABI.

  a が b のサブタイプの場合に真を返します。

  This function only checks for actual subtypes, which means that `__subclasscheck__()` is not called on b. Call `PyObject_IsSubclass()` to do the same check that `issubclass()` would do.

PyObject *PyType_GenericAlloc(PyTypeObject *type, Py_ssize_t nitems)
  戻り値: 新しい参照。 次に属します: Stable ABI.

  Generic handler for the `tp_alloc` slot of a type object. Use Python's default memory allocation mechanism to allocate a new instance and initialize all its contents to `NULL`.

PyObject *PyType_GenericNew(PyTypeObject *type, PyObject *args, PyObject *kwds)
  戻り値: 新しい参照。 次に属します: Stable ABI.

  Generic handler for the `tp_new` slot of a type object. Create a new instance using the type's `tp_alloc` slot.

int PyType_Ready(PyTypeObject *type)
  次に属します: Stable ABI.

  型オブジェクトのファイナライズを行います。この関数は全てのオブジェクトで初期化を完了するために呼び出されなくてはなりません。この関数は、基底クラス型から継承したスロットを型オブジェクトに追加する役割があります。成功した場合には `0` を返し、エラーの場合には `-1` を返して例外情報を設定します。

  注釈

  If some of the base classes implements the GC protocol and the provided type does not include the `Py_TPFLAGS_HAVE_GC` in its flags, then the GC protocol will be automatically implemented from its parents. On the contrary, if the type being created does include `Py_TPFLAGS_HAVE_GC` in its flags then it must implement the GC protocol itself by at least implementing the `tp_traverse` handle.

PyObject *PyType_GetName(PyTypeObject *type)
  戻り値: 新しい参照。 次に属します: Stable ABI (バージョン 3.11 より).

  Return the type's name. Equivalent to getting the type's `__name__` attribute.

  バージョン 3.11 で追加.

PyObject *PyType_GetQualName(PyTypeObject *type)
  戻り値: 新しい参照。 次に属します: Stable ABI (バージョン 3.11 より).

  Return the type's qualified name. Equivalent to getting the type's `__qualname__` attribute.

  バージョン 3.11 で追加.

void *PyType_GetSlot(PyTypeObject *type, int slot)
  次に属します: Stable ABI (バージョン 3.4 より).

  与えられたスロットに格納されている関数ポインタを返します。返り値が `NULL` の場合は、スロットが `NULL` か、関数が不正な引数で呼ばれたことを示します。通常、呼び出し側は返り値のポインタを適切な関数型にキャストします。

  See `PyType_Slot.slot` for possible values of the slot argument.

  バージョン 3.4 で追加.

  バージョン 3.10 で変更: `PyType_GetSlot()` can now accept all types. Previously, it was limited to heap types.

PyObject *PyType_GetModule(PyTypeObject *type)
  次に属します: Stable ABI (バージョン 3.10 より).

  Return the module object associated with the given type when the type was created using `PyType_FromModuleAndSpec()`.

  If no module is associated with the given type, sets `TypeError` and returns `NULL`.

  This function is usually used to get the module in which a method is defined. Note that in such a method, `PyType_GetModule(Py_TYPE(self))` may not return the intended result. `Py_TYPE(self)` may be a subclass of the intended class, and subclasses are not necessarily defined in the same module as their superclass. See `PyCMethod` to get the class that defines the method. See `PyType_GetModuleByDef()` for cases when `PyCMethod` cannot be used.

  バージョン 3.9 で追加.

void *PyType_GetModuleState(PyTypeObject *type)
  次に属します: Stable ABI (バージョン 3.10 より).

  Return the state of the module object associated with the given type. This is a shortcut for calling `PyModule_GetState()` on the result of `PyType_GetModule()`.

  If no module is associated with the given type, sets `TypeError` and returns `NULL`.

  If the type has an associated module but its state is `NULL`, returns `NULL` without setting an exception.

  バージョン 3.9 で追加.

PyObject *PyType_GetModuleByDef(PyTypeObject *type, struct PyModuleDef *def)

  Find the first superclass whose module was created from the given `PyModuleDef` def, and return that module.

  If no module is found, raises a `TypeError` and returns `NULL`.

  This function is intended to be used together with `PyModule_GetState()` to get module state from slot methods (such as `tp_init` or `nb_add`) and other places where a method's defining class cannot be passed using the `PyCMethod` calling convention.

  バージョン 3.11 で追加.

## Creating Heap-Allocated Types

The following functions and structs are used to create heap types.

PyObject *PyType_FromModuleAndSpec(PyObject *module, PyType_Spec *spec, PyObject *bases)
  戻り値: 新しい参照。 次に属します: Stable ABI (バージョン 3.10 より).

  Creates and returns a heap type from the spec (`Py_TPFLAGS_HEAPTYPE`).

  The bases argument can be used to specify base classes; it can either be only one class or a tuple of classes. If bases is `NULL`, the Py_tp_bases slot is used instead. If that also is `NULL`, the Py_tp_base slot is used instead. If that also is `NULL`, the new type derives from `object`.

  The module argument can be used to record the module in which the new class is defined. It must be a module object or `NULL`. If not `NULL`, the module is associated with the new type and can later be retrieved with `PyType_GetModule()`. The associated module is not inherited by subclasses; it must be specified for each class individually.

  This function calls `PyType_Ready()` on the new type.

  バージョン 3.9 で追加.

  バージョン 3.10 で変更: The function now accepts a single class as the bases argument and `NULL` as the `tp_doc` slot.

PyObject *PyType_FromSpecWithBases(PyType_Spec *spec, PyObject *bases)
  戻り値: 新しい参照。 次に属します: Stable ABI (バージョン 3.3 より).

  Equivalent to `PyType_FromModuleAndSpec(NULL, spec, bases)`.

  バージョン 3.3 で追加.

PyObject *PyType_FromSpec(PyType_Spec *spec)
  戻り値: 新しい参照。 次に属します: Stable ABI.

  Equivalent to `PyType_FromSpecWithBases(spec, NULL)`.

type PyType_Spec
  次に属します: Stable ABI (すべてのメンバーを含む).

  Structure defining a type's behavior.

  const char *PyType_Spec.name

    Name of the type, used to set `PyTypeObject.tp_name`.

  int PyType_Spec.basicsize
  int PyType_Spec.itemsize

    Size of the instance in bytes, used to set `PyTypeObject.tp_basicsize` and `PyTypeObject.tp_itemsize`.

  int PyType_Spec.flags

    Type flags, used to set `PyTypeObject.tp_flags`.

    If the `Py_TPFLAGS_HEAPTYPE` flag is not set, `PyType_FromSpecWithBases()` sets it automatically.

  PyType_Slot *PyType_Spec.slots

    Array of `PyType_Slot` structures. Terminated by the special slot value `{0, NULL}`.

type PyType_Slot
  次に属します: Stable ABI (すべてのメンバーを含む).

  Structure defining optional functionality of a type, containing a slot ID and a value pointer.

  int PyType_Slot.slot

    > A slot ID.

    > Slot IDs are named like the field names of the structures `PyTypeObject`, `PyNumberMethods`, `PySequenceMethods`, `PyMappingMethods` and `PyAsyncMethods` with an added `Py_` prefix. For example, use:

    > - `Py_tp_dealloc` to set `PyTypeObject.tp_dealloc`

    > - `Py_nb_add` to set `PyNumberMethods.nb_add`

    > - `Py_sq_length` to set `PySequenceMethods.sq_length`

    > The following fields cannot be set at all using `PyType_Spec` and `PyType_Slot`:

    > - `tp_dict`

    > - `tp_mro`

    > - `tp_cache`

    > - `tp_subclasses`

    > - `tp_weaklist`

    > - `tp_vectorcall`

    > - `tp_weaklistoffset` (see PyMemberDef)

    > - `tp_dictoffset` (see PyMemberDef)

    > - `tp_vectorcall_offset` (see PyMemberDef)

    > Setting `Py_tp_bases` or `Py_tp_base` may be problematic on some platforms. To avoid issues, use the bases argument of `PyType_FromSpecWithBases()` instead.

    バージョン 3.9 で変更: Slots in `PyBufferProcs` may be set in the unlimited API.

    バージョン 3.11 で変更: `bf_getbuffer` and `bf_releasebuffer` are now available under the limited API.

  void *PyType_Slot.pfunc

    The desired value of the slot. In most cases, this is a pointer to a function.

    Slots other than `Py_tp_doc` may not be `NULL`.