类型对象 ¶

type PyTypeObject ¶: 属于 Limited API (as an opaque struct).
The C structure of the objects used to describe built-in types.

PyTypeObject PyType_Type ¶: 属于稳定 ABI (应用程序二进制接口) .
This is the type object for type objects; it is the same object as type 在 Python 层。

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 ( ) ¶: 属于稳定 ABI (应用程序二进制接口) .
Clear the internal lookup cache. Return the current version tag.

unsigned long PyType_GetFlags ( PyTypeObject * type ) ¶

属于稳定 ABI (应用程序二进制接口) .

返回 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 .

Added in version 3.2.

3.4 版改变： The return type is now unsigned long 而不是 long .

Creating Heap-Allocated Types ¶

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

PyObject * PyType_FromMetaclass ( PyTypeObject * metaclass , PyObject * 模块 , PyType_Spec * spec , PyObject * bases ) ¶

属于稳定 ABI (应用程序二进制接口) since version 3.12.

Create and return a heap type 从 spec (见 Py_TPFLAGS_HEAPTYPE ).

The metaclass metaclass is used to construct the resulting type object. When metaclass is NULL , the metaclass is derived from bases (或 Py_tp_base[s] slots if bases is NULL , see below).

Metaclasses that override tp_new are not supported, except if tp_new is NULL . (For backwards compatibility, other PyType_From* functions allow such metaclasses. They ignore tp_new , which may result in incomplete initialization. This is deprecated and in Python 3.14+ such metaclasses will not be supported.)

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 ， Py_tp_bases slot is used instead. If that also is NULL ， Py_tp_base slot is used instead. If that also is NULL , the new type derives from object .

The 模块 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.

此函数调用 PyType_Ready() on the new type.

Note that this function does not fully match the behavior of calling type() or using the class statement. With user-provided base types or metaclasses, prefer 调用 type (or the metaclass) over PyType_From* functions. Specifically:

__new__() is not called on the new class (and it must be set to type.__new__ ).
__init__() is not called on the new class.
__init_subclass__() is not called on any bases.
__set_name__() is not called on new descriptors.

3.12 版添加。

PyObject * PyType_FromModuleAndSpec ( PyObject * 模块 , PyType_Spec * spec , PyObject * bases ) ¶

返回值：新引用。 属于稳定 ABI (应用程序二进制接口) since version 3.10.

相当于 PyType_FromMetaclass(NULL, module, spec, bases) .

Added in version 3.9.

3.10 版改变： The function now accepts a single class as the bases argument and NULL 作为 tp_doc 槽。

3.12 版改变： The function now finds and uses a metaclass corresponding to the provided base classes. Previously, only type instances were returned.

The tp_new of the metaclass is ignored . which may result in incomplete initialization. Creating classes whose metaclass overrides tp_new is deprecated and in Python 3.14+ it will be no longer allowed.

PyObject * PyType_FromSpecWithBases ( PyType_Spec * spec , PyObject * bases ) ¶

返回值：新引用。 属于稳定 ABI (应用程序二进制接口) since version 3.3.

相当于 PyType_FromMetaclass(NULL, NULL, spec, bases) .

Added in version 3.3.

3.12 版改变： The function now finds and uses a metaclass corresponding to the provided base classes. Previously, only type instances were returned.

PyObject * PyType_FromSpec ( PyType_Spec * spec ) ¶

返回值：新引用。 属于稳定 ABI (应用程序二进制接口) .

相当于 PyType_FromMetaclass(NULL, NULL, spec, NULL) .

3.12 版改变： The function now finds and uses a metaclass corresponding to the base classes provided in Py_tp_base[s] slots. Previously, only type instances were returned.

type PyType_Spec ¶

属于稳定 ABI (应用程序二进制接口) (including all members).

Structure defining a type’s behavior.

const char * 名称 ¶: Name of the type, used to set PyTypeObject.tp_name .

int basicsize ¶

If positive, specifies the size of the instance in bytes. It is used to set PyTypeObject.tp_basicsize .

If zero, specifies that tp_basicsize should be inherited.

If negative, the absolute value specifies how much space instances of the class need in addition to the superclass. Use PyObject_GetTypeData() to get a pointer to subclass-specific memory reserved this way.

3.12 版改变： Previously, this field could not be negative.

int itemsize ¶

Size of one element of a variable-size type, in bytes. Used to set PyTypeObject.tp_itemsize 。见 tp_itemsize documentation for caveats.

If zero, tp_itemsize is inherited. Extending arbitrary variable-sized classes is dangerous, since some types use a fixed offset for variable-sized memory, which can then overlap fixed-sized memory used by a subclass. To help prevent mistakes, inheriting itemsize is only possible in the following situations:

The base is not variable-sized (its tp_itemsize ).
The requested PyType_Spec.basicsize is positive, suggesting that the memory layout of the base class is known.
The requested PyType_Spec.basicsize is zero, suggesting that the subclass does not access the instance’s memory directly.
With the Py_TPFLAGS_ITEMS_AT_END 标志。

unsigned int flags ¶

Type flags, used to set PyTypeObject.tp_flags .

若 Py_TPFLAGS_HEAPTYPE flag is not set, PyType_FromSpecWithBases() sets it automatically.

PyType_Slot * slots ¶

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

Each slot ID should be specified at most once.

type PyType_Slot ¶

属于稳定 ABI (应用程序二进制接口) (including all members).

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

int 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 “offset” fields cannot be set using PyType_Slot :

tp_weaklistoffset (使用 Py_TPFLAGS_MANAGED_WEAKREF instead if possible)
tp_dictoffset (使用 Py_TPFLAGS_MANAGED_DICT instead if possible)
tp_vectorcall_offset (使用 "__vectorcalloffset__" in PyMemberDef )

If it is not possible to switch to a MANAGED flag (for example, for vectorcall or to support Python older than 3.12), specify the offset in Py_tp_members 。见 PyMemberDef documentation 了解细节。

The following fields cannot be set at all when creating a heap type:

tp_vectorcall (使用 tp_new and/or tp_init )
Internal fields: tp_dict , tp_mro , tp_cache , tp_subclasses ，和 tp_weaklist .

设置 Py_tp_bases or Py_tp_base may be problematic on some platforms. To avoid issues, use the bases 自变量 PyType_FromSpecWithBases() 代替。

3.9 版改变： Slots in PyBufferProcs may be set in the unlimited API.

3.11 版改变： bf_getbuffer and bf_releasebuffer are now available under the limited API .

void * 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 .

类型对象 ¶

Creating Heap-Allocated Types ¶

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