# 类型对象

`PyTypeObject`

  对象的 C 结构用于描述 built-in 类型。

PyObject* `PyType_Type`

  This is the type object for type objects; it is the same object as `type` and `types.TypeType` in the Python layer.

int `PyType_Check`(PyObject *o)

  如果对象 o 是一个类型对象，包括继承于标准类型对象的类型实例，返回真。在其它所有情况下返回假。

int `PyType_CheckExact`(PyObject *o)

  如果对象 o 是一个类型对象，但不是标准类型对象的子类型时，返回真。在其它所有情况下返回假。

  2.2 新版功能.

unsigned int `PyType_ClearCache`()

  Clear the internal lookup cache. Return the current version tag.

  2.6 新版功能.

void `PyType_Modified`(PyTypeObject *type)

  Invalidate the internal lookup cache for the type and all of its subtypes. This function must be called after any manual modification of the attributes or base classes of the type.

  2.6 新版功能.

int `PyType_HasFeature`(PyObject *o, int feature)

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

int `PyType_IS_GC`(PyObject *o)

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

  2.0 新版功能.

int `PyType_IsSubtype`(PyTypeObject *a, PyTypeObject *b)

  Return true if a is a subtype of b.

  2.2 新版功能.

  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)
  Return value: New reference.

  2.2 新版功能.

  在 2.5 版更改: This function used an `int` type for nitems. This might require changes in your code for properly supporting 64-bit systems.

PyObject* `PyType_GenericNew`(PyTypeObject *type, PyObject *args, PyObject *kwds)
  Return value: New reference.

  2.2 新版功能.

int `PyType_Ready`(PyTypeObject *type)

  Finalize a type object. This should be called on all type objects to finish their initialization. This function is responsible for adding inherited slots from a type’s base class. Return `0` on success, or return `-1` and sets an exception on error.

  2.2 新版功能.