/
usr
/
share
/
doc
/
python3-docs
/
html
/
c-api
/
/usr/share/doc/python3-docs/html/c-api
mkdir
upload
Name
Size
Mode
Actions
abstract.html
9716
0644
edit
dl
rm
allocation.html
14728
0644
edit
dl
rm
apiabiversion.html
10681
0644
edit
dl
rm
arg.html
89735
0644
edit
dl
rm
bool.html
10333
0644
edit
dl
rm
buffer.html
64150
0644
edit
dl
rm
bytearray.html
15098
0644
edit
dl
rm
bytes.html
25487
0644
edit
dl
rm
capsule.html
21699
0644
edit
dl
rm
cell.html
11942
0644
edit
dl
rm
code.html
12388
0644
edit
dl
rm
codec.html
22641
0644
edit
dl
rm
complex.html
21268
0644
edit
dl
rm
concrete.html
17602
0644
edit
dl
rm
conversion.html
19525
0644
edit
dl
rm
coro.html
9452
0644
edit
dl
rm
datetime.html
26513
0644
edit
dl
rm
descriptor.html
11959
0644
edit
dl
rm
dict.html
35244
0644
edit
dl
rm
exceptions.html
128414
0644
edit
dl
rm
file.html
14544
0644
edit
dl
rm
float.html
15155
0644
edit
dl
rm
function.html
18215
0644
edit
dl
rm
gcsupport.html
23787
0644
edit
dl
rm
gen.html
10939
0644
edit
dl
rm
import.html
42920
0644
edit
dl
rm
index.html
15759
0644
edit
dl
rm
init.html
116862
0644
edit
dl
rm
intro.html
68136
0644
edit
dl
rm
iter.html
10062
0644
edit
dl
rm
iterator.html
11928
0644
edit
dl
rm
list.html
22504
0644
edit
dl
rm
long.html
44839
0644
edit
dl
rm
mapping.html
17524
0644
edit
dl
rm
marshal.html
16935
0644
edit
dl
rm
memory.html
58531
0644
edit
dl
rm
memoryview.html
13510
0644
edit
dl
rm
method.html
17051
0644
edit
dl
rm
module.html
56821
0644
edit
dl
rm
none.html
8755
0644
edit
dl
rm
number.html
44801
0644
edit
dl
rm
objbuffer.html
12624
0644
edit
dl
rm
object.html
60861
0644
edit
dl
rm
objimpl.html
8087
0644
edit
dl
rm
refcounting.html
13454
0644
edit
dl
rm
reflection.html
11189
0644
edit
dl
rm
sequence.html
28925
0644
edit
dl
rm
set.html
31197
0644
edit
dl
rm
slice.html
13459
0644
edit
dl
rm
stable.html
9193
0644
edit
dl
rm
structures.html
37151
0644
edit
dl
rm
sys.html
35639
0644
edit
dl
rm
tuple.html
30022
0644
edit
dl
rm
type.html
18813
0644
edit
dl
rm
typeobj.html
164125
0644
edit
dl
rm
unicode.html
188046
0644
edit
dl
rm
utilities.html
8966
0644
edit
dl
rm
veryhigh.html
54572
0644
edit
dl
rm
weakref.html
13615
0644
edit
dl
rm
Edit:
/usr/share/doc/python3-docs/html/c-api/refcounting.html
(13454B)
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="X-UA-Compatible" content="IE=Edge" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Reference Counting — Python 3.6.7 documentation</title> <link rel="stylesheet" href="../_static/pydoctheme.css" type="text/css" /> <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> <script type="text/javascript" id="documentation_options" data-url_root="../" src="../_static/documentation_options.js"></script> <script type="text/javascript" src="../_static/jquery.js"></script> <script type="text/javascript" src="../_static/underscore.js"></script> <script type="text/javascript" src="../_static/doctools.js"></script> <script type="text/javascript" src="../_static/sidebar.js"></script> <link rel="search" type="application/opensearchdescription+xml" title="Search within Python 3.6.7 documentation" href="../_static/opensearch.xml"/> <link rel="author" title="About these documents" href="../about.html" /> <link rel="index" title="Index" href="../genindex.html" /> <link rel="search" title="Search" href="../search.html" /> <link rel="copyright" title="Copyright" href="../copyright.html" /> <link rel="next" title="Exception Handling" href="exceptions.html" /> <link rel="prev" title="The Very High Level Layer" href="veryhigh.html" /> <link rel="shortcut icon" type="image/png" href="../_static/py.png" /> <link rel="canonical" href="https://docs.python.org/3/c-api/refcounting.html" /> <script type="text/javascript" src="../_static/copybutton.js"></script> </head><body> <div class="related" role="navigation" aria-label="related navigation"> <h3>Navigation</h3> <ul> <li class="right" style="margin-right: 10px"> <a href="../genindex.html" title="General Index" accesskey="I">index</a></li> <li class="right" > <a href="../py-modindex.html" title="Python Module Index" >modules</a> |</li> <li class="right" > <a href="exceptions.html" title="Exception Handling" accesskey="N">next</a> |</li> <li class="right" > <a href="veryhigh.html" title="The Very High Level Layer" accesskey="P">previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="https://www.python.org/">Python</a> »</li> <li> <a href="../index.html">3.6.7 Documentation</a> » </li> <li class="nav-item nav-item-1"><a href="index.html" accesskey="U">Python/C API Reference Manual</a> »</li> <li class="right"> <div class="inline-search" style="display: none" role="search"> <form class="inline-search" action="../search.html" method="get"> <input placeholder="Quick search" type="text" name="q" /> <input type="submit" value="Go" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> </div> <script type="text/javascript">$('.inline-search').show(0);</script> | </li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body" role="main"> <div class="section" id="reference-counting"> <span id="countingrefs"></span><h1>Reference Counting<a class="headerlink" href="#reference-counting" title="Permalink to this headline">¶</a></h1> <p>The macros in this section are used for managing reference counts of Python objects.</p> <dl class="function"> <dt id="c.Py_INCREF"> void <code class="descname">Py_INCREF</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *o</em><span class="sig-paren">)</span><a class="headerlink" href="#c.Py_INCREF" title="Permalink to this definition">¶</a></dt> <dd><p>Increment the reference count for object <em>o</em>. The object must not be <em>NULL</em>; if you aren’t sure that it isn’t <em>NULL</em>, use <a class="reference internal" href="#c.Py_XINCREF" title="Py_XINCREF"><code class="xref c c-func docutils literal notranslate"><span class="pre">Py_XINCREF()</span></code></a>.</p> </dd></dl> <dl class="function"> <dt id="c.Py_XINCREF"> void <code class="descname">Py_XINCREF</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *o</em><span class="sig-paren">)</span><a class="headerlink" href="#c.Py_XINCREF" title="Permalink to this definition">¶</a></dt> <dd><p>Increment the reference count for object <em>o</em>. The object may be <em>NULL</em>, in which case the macro has no effect.</p> </dd></dl> <dl class="function"> <dt id="c.Py_DECREF"> void <code class="descname">Py_DECREF</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *o</em><span class="sig-paren">)</span><a class="headerlink" href="#c.Py_DECREF" title="Permalink to this definition">¶</a></dt> <dd><p>Decrement the reference count for object <em>o</em>. The object must not be <em>NULL</em>; if you aren’t sure that it isn’t <em>NULL</em>, use <a class="reference internal" href="#c.Py_XDECREF" title="Py_XDECREF"><code class="xref c c-func docutils literal notranslate"><span class="pre">Py_XDECREF()</span></code></a>. If the reference count reaches zero, the object’s type’s deallocation function (which must not be <em>NULL</em>) is invoked.</p> <div class="admonition warning"> <p class="first admonition-title">Warning</p> <p class="last">The deallocation function can cause arbitrary Python code to be invoked (e.g. when a class instance with a <a class="reference internal" href="../reference/datamodel.html#object.__del__" title="object.__del__"><code class="xref py py-meth docutils literal notranslate"><span class="pre">__del__()</span></code></a> method is deallocated). While exceptions in such code are not propagated, the executed code has free access to all Python global variables. This means that any object that is reachable from a global variable should be in a consistent state before <a class="reference internal" href="#c.Py_DECREF" title="Py_DECREF"><code class="xref c c-func docutils literal notranslate"><span class="pre">Py_DECREF()</span></code></a> is invoked. For example, code to delete an object from a list should copy a reference to the deleted object in a temporary variable, update the list data structure, and then call <a class="reference internal" href="#c.Py_DECREF" title="Py_DECREF"><code class="xref c c-func docutils literal notranslate"><span class="pre">Py_DECREF()</span></code></a> for the temporary variable.</p> </div> </dd></dl> <dl class="function"> <dt id="c.Py_XDECREF"> void <code class="descname">Py_XDECREF</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *o</em><span class="sig-paren">)</span><a class="headerlink" href="#c.Py_XDECREF" title="Permalink to this definition">¶</a></dt> <dd><p>Decrement the reference count for object <em>o</em>. The object may be <em>NULL</em>, in which case the macro has no effect; otherwise the effect is the same as for <a class="reference internal" href="#c.Py_DECREF" title="Py_DECREF"><code class="xref c c-func docutils literal notranslate"><span class="pre">Py_DECREF()</span></code></a>, and the same warning applies.</p> </dd></dl> <dl class="function"> <dt id="c.Py_CLEAR"> void <code class="descname">Py_CLEAR</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *o</em><span class="sig-paren">)</span><a class="headerlink" href="#c.Py_CLEAR" title="Permalink to this definition">¶</a></dt> <dd><p>Decrement the reference count for object <em>o</em>. The object may be <em>NULL</em>, in which case the macro has no effect; otherwise the effect is the same as for <a class="reference internal" href="#c.Py_DECREF" title="Py_DECREF"><code class="xref c c-func docutils literal notranslate"><span class="pre">Py_DECREF()</span></code></a>, except that the argument is also set to <em>NULL</em>. The warning for <a class="reference internal" href="#c.Py_DECREF" title="Py_DECREF"><code class="xref c c-func docutils literal notranslate"><span class="pre">Py_DECREF()</span></code></a> does not apply with respect to the object passed because the macro carefully uses a temporary variable and sets the argument to <em>NULL</em> before decrementing its reference count.</p> <p>It is a good idea to use this macro whenever decrementing the value of a variable that might be traversed during garbage collection.</p> </dd></dl> <p>The following functions are for runtime dynamic embedding of Python: <code class="docutils literal notranslate"><span class="pre">Py_IncRef(PyObject</span> <span class="pre">*o)</span></code>, <code class="docutils literal notranslate"><span class="pre">Py_DecRef(PyObject</span> <span class="pre">*o)</span></code>. They are simply exported function versions of <a class="reference internal" href="#c.Py_XINCREF" title="Py_XINCREF"><code class="xref c c-func docutils literal notranslate"><span class="pre">Py_XINCREF()</span></code></a> and <a class="reference internal" href="#c.Py_XDECREF" title="Py_XDECREF"><code class="xref c c-func docutils literal notranslate"><span class="pre">Py_XDECREF()</span></code></a>, respectively.</p> <p>The following functions or macros are only for use within the interpreter core: <code class="xref c c-func docutils literal notranslate"><span class="pre">_Py_Dealloc()</span></code>, <code class="xref c c-func docutils literal notranslate"><span class="pre">_Py_ForgetReference()</span></code>, <code class="xref c c-func docutils literal notranslate"><span class="pre">_Py_NewReference()</span></code>, as well as the global variable <code class="xref c c-data docutils literal notranslate"><span class="pre">_Py_RefTotal</span></code>.</p> </div> </div> </div> </div> <div class="sphinxsidebar" role="navigation" aria-label="main navigation"> <div class="sphinxsidebarwrapper"> <h4>Previous topic</h4> <p class="topless"><a href="veryhigh.html" title="previous chapter">The Very High Level Layer</a></p> <h4>Next topic</h4> <p class="topless"><a href="exceptions.html" title="next chapter">Exception Handling</a></p> <div role="note" aria-label="source link"> <h3>This Page</h3> <ul class="this-page-menu"> <li><a href="../bugs.html">Report a Bug</a></li> <li> <a href="https://github.com/python/cpython/blob/3.6/Doc/c-api/refcounting.rst" rel="nofollow">Show Source </a> </li> </ul> </div> </div> </div> <div class="clearer"></div> </div> <div class="related" role="navigation" aria-label="related navigation"> <h3>Navigation</h3> <ul> <li class="right" style="margin-right: 10px"> <a href="../genindex.html" title="General Index" >index</a></li> <li class="right" > <a href="../py-modindex.html" title="Python Module Index" >modules</a> |</li> <li class="right" > <a href="exceptions.html" title="Exception Handling" >next</a> |</li> <li class="right" > <a href="veryhigh.html" title="The Very High Level Layer" >previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="https://www.python.org/">Python</a> »</li> <li> <a href="../index.html">3.6.7 Documentation</a> » </li> <li class="nav-item nav-item-1"><a href="index.html" >Python/C API Reference Manual</a> »</li> <li class="right"> <div class="inline-search" style="display: none" role="search"> <form class="inline-search" action="../search.html" method="get"> <input placeholder="Quick search" type="text" name="q" /> <input type="submit" value="Go" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> </div> <script type="text/javascript">$('.inline-search').show(0);</script> | </li> </ul> </div> <div class="footer"> © <a href="../copyright.html">Copyright</a> 2001-2023, Python Software Foundation. <br /> The Python Software Foundation is a non-profit corporation. <a href="https://www.python.org/psf/donations/">Please donate.</a> <br /> Last updated on Dec 18, 2023. <a href="../bugs.html">Found a bug</a>? <br /> Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 1.7.6. </div> </body> </html>
Save
cmd:
run