Class and Instance Objects — Python 2.7.18 documentation

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# Class and Instance Objects

Note that the class objects described here represent old-style classes, which will go away in Python 3. When creating new types for extension modules, you will want to work with type objects (section Type Objects).

`PyClassObject`

  The C structure of the objects used to describe built-in classes.

PyObject* `PyClass_Type`

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

int `PyClass_Check`(PyObject *o)

  Return true if the object o is a class object, including instances of types derived from the standard class object. Return false in all other cases.

int `PyClass_IsSubclass`(PyObject *klass, PyObject *base)

  Return true if klass is a subclass of base. Return false in all other cases.

There are very few functions specific to instance objects.

PyTypeObject `PyInstance_Type`

  Type object for class instances.

int `PyInstance_Check`(PyObject *obj)

  Return true if obj is an instance.

PyObject* `PyInstance_New`(PyObject *class, PyObject *arg, PyObject *kw)
  Return value: New reference.

  Create a new instance of a specific class. The parameters arg and kw are used as the positional and keyword parameters to the object’s constructor.

PyObject* `PyInstance_NewRaw`(PyObject *class, PyObject *dict)
  Return value: New reference.

  Create a new instance of a specific class without calling its constructor. class is the class of new object. The dict parameter will be used as the object’s `__dict__`; if NULL, a new dictionary will be created for the instance.