githubmirror/cpython

Doc/c-api/none.rst

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Stéphane Wirtel

Doc: Replace the deprecated highlightlang directive by highlight. (#13377)

17 май 2019, 12:55

17 май 2019, 12:55cbb6484

.. highlight:: c

.. _noneobject:

The ``None`` Object
-------------------

.. index:: object: None

Note that the :c:type:`PyTypeObject` for ``None`` is not directly exposed in the
Python/C API.  Since ``None`` is a singleton, testing for object identity (using
``==`` in C) is sufficient. There is no :c:func:`PyNone_Check` function for the
same reason.


.. c:var:: PyObject* Py_None

   The Python ``None`` object, denoting lack of value.  This object has no methods.
   It needs to be treated just like any other object with respect to reference
   counts.


.. c:macro:: Py_RETURN_NONE

   Properly handle returning :c:data:`Py_None` from within a C function (that is,
   increment the reference count of ``None`` and return it.)