참조 횟수
*********

이 섹션의 매크로는 파이썬 객체의 참조 횟수를 관리하는 데 사용됩니다.

void Py_INCREF(PyObject *o)

   Indicate taking a new *strong reference* to object *o*, indicating
   it is in use and should not be destroyed.

   This function is usually used to convert a *borrowed reference* to
   a *strong reference* in-place. The "Py_NewRef()" function can be
   used to create a new *strong reference*.

   When done using the object, release it by calling "Py_DECREF()".

   The object must not be "NULL"; if you aren't sure that it isn't
   "NULL", use "Py_XINCREF()".

   Do not expect this function to actually modify *o* in any way.

void Py_XINCREF(PyObject *o)

   Similar to "Py_INCREF()", but the object *o* can be "NULL", in
   which case this has no effect.

   See also "Py_XNewRef()".

PyObject *Py_NewRef(PyObject *o)
    * Part of the Stable ABI since version 3.10.*

   Create a new *strong reference* to an object: call "Py_INCREF()" on
   *o* and return the object *o*.

   When the *strong reference* is no longer needed, "Py_DECREF()"
   should be called on it to release the reference.

   The object *o* must not be "NULL"; use "Py_XNewRef()" if *o* can be
   "NULL".

   For example:

      Py_INCREF(obj);
      self->attr = obj;

   can be written as:

      self->attr = Py_NewRef(obj);

   See also "Py_INCREF()".

   버전 3.10에 추가.

PyObject *Py_XNewRef(PyObject *o)
    * Part of the Stable ABI since version 3.10.*

   Similar to "Py_NewRef()", but the object *o* can be NULL.

   If the object *o* is "NULL", the function just returns "NULL".

   버전 3.10에 추가.

void Py_DECREF(PyObject *o)

   Release a *strong reference* to object *o*, indicating the
   reference is no longer used.

   Once the last *strong reference* is released (i.e. the object's
   reference count reaches 0), the object's type's deallocation
   function (which must not be "NULL") is invoked.

   This function is usually used to delete a *strong reference* before
   exiting its scope.

   The object must not be "NULL"; if you aren't sure that it isn't
   "NULL", use "Py_XDECREF()".

   Do not expect this function to actually modify *o* in any way.

   경고:

     할당 해제 함수는 임의의 파이썬 코드가 호출되도록 할 수 있습니다 (
     예를 들어, "__del__()" 메서드가 있는 클래스 인스턴스가 할당 해제
     될 때). 이러한 코드에서의 예외는 전파되지 않지만, 실행된 코드는
     모든 파이썬 전역 변수에 자유롭게 액세스할 수 있습니다. 이것은
     "Py_DECREF()"가 호출되기 전에 전역 변수에서 도달할 수 있는 모든
     객체가 일관성 있는 상태에 있어야 함을 뜻합니다. 예를 들어, 리스트
     에서 객체를 삭제하는 코드는 삭제된 객체에 대한 참조를 임시 변수에
     복사하고, 리스트 데이터 구조를 갱신한 다음, 임시 변수에 대해
     "Py_DECREF()"를 호출해야 합니다.

void Py_XDECREF(PyObject *o)

   Similar to "Py_DECREF()", but the object *o* can be "NULL", in
   which case this has no effect. The same warning from "Py_DECREF()"
   applies here as well.

void Py_CLEAR(PyObject *o)

   Release a *strong reference* for object *o*. The object may be
   "NULL", in which case the macro has no effect; otherwise the effect
   is the same as for "Py_DECREF()", except that the argument is also
   set to "NULL".  The warning for "Py_DECREF()" does not apply with
   respect to the object passed because the macro carefully uses a
   temporary variable and sets the argument to "NULL" before releasing
   the reference.

   It is a good idea to use this macro whenever releasing a reference
   to an object that might be traversed during garbage collection.

void Py_IncRef(PyObject *o)
    * Part of the Stable ABI.*

   Indicate taking a new *strong reference* to object *o*. A function
   version of "Py_XINCREF()". It can be used for runtime dynamic
   embedding of Python.

void Py_DecRef(PyObject *o)
    * Part of the Stable ABI.*

   Release a *strong reference* to object *o*. A function version of
   "Py_XDECREF()". It can be used for runtime dynamic embedding of
   Python.

다음 함수나 매크로는 인터프리터 코어에서만 사용할 수 있습니다:
"_Py_Dealloc()", "_Py_ForgetReference()", "_Py_NewReference()" 및 전역
변수 "_Py_RefTotal".
