<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta charset="utf-8" />
<title>Allocating Objects on the Heap — Python 2.7.17 documentation</title>
<link rel="stylesheet" href="../_static/classic.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/language_data.js"></script>
<script type="text/javascript" src="../_static/sidebar.js"></script>
<link rel="search" type="application/opensearchdescription+xml"
title="Search within Python 2.7.17 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="Common Object Structures" href="structures.html" />
<link rel="prev" title="Object Implementation Support" href="objimpl.html" />
<link rel="shortcut icon" type="image/png" href="../_static/py.png" />
<link rel="canonical" href="https://docs.python.org/2/c-api/allocation.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="structures.html" title="Common Object Structures"
accesskey="N">next</a> |</li>
<li class="right" >
<a href="objimpl.html" title="Object Implementation Support"
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">Python 2.7.17 documentation</a> »
</li>
<li class="nav-item nav-item-1"><a href="index.html" >Python/C API Reference Manual</a> »</li>
<li class="nav-item nav-item-2"><a href="objimpl.html" accesskey="U">Object Implementation Support</a> »</li>
</ul>
</div>
<div class="document">
<div class="documentwrapper">
<div class="bodywrapper">
<div class="body" role="main">
<div class="section" id="allocating-objects-on-the-heap">
<span id="allocating-objects"></span><h1>Allocating Objects on the Heap<a class="headerlink" href="#allocating-objects-on-the-heap" title="Permalink to this headline">¶</a></h1>
<dl class="function">
<dt id="c._PyObject_New">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="descname">_PyObject_New</code><span class="sig-paren">(</span><a class="reference internal" href="type.html#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a><em> *type</em><span class="sig-paren">)</span><a class="headerlink" href="#c._PyObject_New" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: New reference.</em></dd></dl>
<dl class="function">
<dt id="c._PyObject_NewVar">
<a class="reference internal" href="structures.html#c.PyVarObject" title="PyVarObject">PyVarObject</a>* <code class="descname">_PyObject_NewVar</code><span class="sig-paren">(</span><a class="reference internal" href="type.html#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a><em> *type</em>, Py_ssize_t<em> size</em><span class="sig-paren">)</span><a class="headerlink" href="#c._PyObject_NewVar" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: New reference.</em><div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 2.5: </span>This function used an <code class="xref c c-type docutils literal notranslate"><span class="pre">int</span></code> type for <em>size</em>. This might require
changes in your code for properly supporting 64-bit systems.</p>
</div>
</dd></dl>
<dl class="function">
<dt id="c._PyObject_Del">
void <code class="descname">_PyObject_Del</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *op</em><span class="sig-paren">)</span><a class="headerlink" href="#c._PyObject_Del" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>
<dl class="function">
<dt id="c.PyObject_Init">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="descname">PyObject_Init</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *op</em>, <a class="reference internal" href="type.html#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a><em> *type</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_Init" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: Borrowed reference.</em><p>Initialize a newly-allocated object <em>op</em> with its type and initial
reference. Returns the initialized object. If <em>type</em> indicates that the
object participates in the cyclic garbage detector, it is added to the
detector’s set of observed objects. Other fields of the object are not
affected.</p>
</dd></dl>
<dl class="function">
<dt id="c.PyObject_InitVar">
<a class="reference internal" href="structures.html#c.PyVarObject" title="PyVarObject">PyVarObject</a>* <code class="descname">PyObject_InitVar</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyVarObject" title="PyVarObject">PyVarObject</a><em> *op</em>, <a class="reference internal" href="type.html#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a><em> *type</em>, Py_ssize_t<em> size</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_InitVar" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: Borrowed reference.</em><p>This does everything <a class="reference internal" href="#c.PyObject_Init" title="PyObject_Init"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_Init()</span></code></a> does, and also initializes the
length information for a variable-size object.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 2.5: </span>This function used an <code class="xref c c-type docutils literal notranslate"><span class="pre">int</span></code> type for <em>size</em>. This might require
changes in your code for properly supporting 64-bit systems.</p>
</div>
</dd></dl>
<dl class="function">
<dt id="c.PyObject_New">
TYPE* <code class="descname">PyObject_New</code><span class="sig-paren">(</span>TYPE, <a class="reference internal" href="type.html#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a><em> *type</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_New" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: New reference.</em><p>Allocate a new Python object using the C structure type <em>TYPE</em> and the
Python type object <em>type</em>. Fields not defined by the Python object header
are not initialized; the object’s reference count will be one. The size of
the memory allocation is determined from the <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_basicsize" title="PyTypeObject.tp_basicsize"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_basicsize</span></code></a> field of
the type object.</p>
</dd></dl>
<dl class="function">
<dt id="c.PyObject_NewVar">
TYPE* <code class="descname">PyObject_NewVar</code><span class="sig-paren">(</span>TYPE, <a class="reference internal" href="type.html#c.PyTypeObject" title="PyTypeObject">PyTypeObject</a><em> *type</em>, Py_ssize_t<em> size</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_NewVar" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: New reference.</em><p>Allocate a new Python object using the C structure type <em>TYPE</em> and the
Python type object <em>type</em>. Fields not defined by the Python object header
are not initialized. The allocated memory allows for the <em>TYPE</em> structure
plus <em>size</em> fields of the size given by the <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_itemsize" title="PyTypeObject.tp_itemsize"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_itemsize</span></code></a> field of
<em>type</em>. This is useful for implementing objects like tuples, which are
able to determine their size at construction time. Embedding the array of
fields into the same allocation decreases the number of allocations,
improving the memory management efficiency.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 2.5: </span>This function used an <code class="xref c c-type docutils literal notranslate"><span class="pre">int</span></code> type for <em>size</em>. This might require
changes in your code for properly supporting 64-bit systems.</p>
</div>
</dd></dl>
<dl class="function">
<dt id="c.PyObject_Del">
void <code class="descname">PyObject_Del</code><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *op</em><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_Del" title="Permalink to this definition">¶</a></dt>
<dd><p>Releases memory allocated to an object using <a class="reference internal" href="#c.PyObject_New" title="PyObject_New"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_New()</span></code></a> or
<a class="reference internal" href="#c.PyObject_NewVar" title="PyObject_NewVar"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_NewVar()</span></code></a>. This is normally called from the
<a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_dealloc" title="PyTypeObject.tp_dealloc"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_dealloc</span></code></a> handler specified in the object’s type. The fields of
the object should not be accessed after this call as the memory is no
longer a valid Python object.</p>
</dd></dl>
<dl class="function">
<dt id="c.Py_InitModule">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="descname">Py_InitModule</code><span class="sig-paren">(</span>char<em> *name</em>, <a class="reference internal" href="structures.html#c.PyMethodDef" title="PyMethodDef">PyMethodDef</a><em> *methods</em><span class="sig-paren">)</span><a class="headerlink" href="#c.Py_InitModule" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: Borrowed reference.</em><p>Create a new module object based on a name and table of functions,
returning the new module object.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 2.3: </span>Older versions of Python did not support <em>NULL</em> as the value for the
<em>methods</em> argument.</p>
</div>
</dd></dl>
<dl class="function">
<dt id="c.Py_InitModule3">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="descname">Py_InitModule3</code><span class="sig-paren">(</span>char<em> *name</em>, <a class="reference internal" href="structures.html#c.PyMethodDef" title="PyMethodDef">PyMethodDef</a><em> *methods</em>, char<em> *doc</em><span class="sig-paren">)</span><a class="headerlink" href="#c.Py_InitModule3" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: Borrowed reference.</em><p>Create a new module object based on a name and table of functions,
returning the new module object. If <em>doc</em> is non-<em>NULL</em>, it will be used
to define the docstring for the module.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 2.3: </span>Older versions of Python did not support <em>NULL</em> as the value for the
<em>methods</em> argument.</p>
</div>
</dd></dl>
<dl class="function">
<dt id="c.Py_InitModule4">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a>* <code class="descname">Py_InitModule4</code><span class="sig-paren">(</span>char<em> *name</em>, <a class="reference internal" href="structures.html#c.PyMethodDef" title="PyMethodDef">PyMethodDef</a><em> *methods</em>, char<em> *doc</em>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a><em> *self</em>, int<em> apiver</em><span class="sig-paren">)</span><a class="headerlink" href="#c.Py_InitModule4" title="Permalink to this definition">¶</a></dt>
<dd><em class="refcount">Return value: Borrowed reference.</em><p>Create a new module object based on a name and table of functions,
returning the new module object. If <em>doc</em> is non-<em>NULL</em>, it will be used
to define the docstring for the module. If <em>self</em> is non-<em>NULL</em>, it will
be passed to the functions of the module as their (otherwise <em>NULL</em>) first
parameter. (This was added as an experimental feature, and there are no
known uses in the current version of Python.) For <em>apiver</em>, the only value
which should be passed is defined by the constant
<code class="xref py py-const docutils literal notranslate"><span class="pre">PYTHON_API_VERSION</span></code>.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>Most uses of this function should probably be using the
<a class="reference internal" href="#c.Py_InitModule3" title="Py_InitModule3"><code class="xref c c-func docutils literal notranslate"><span class="pre">Py_InitModule3()</span></code></a> instead; only use this if you are sure you need
it.</p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 2.3: </span>Older versions of Python did not support <em>NULL</em> as the value for the
<em>methods</em> argument.</p>
</div>
</dd></dl>
<dl class="var">
<dt id="c._Py_NoneStruct">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject">PyObject</a> <code class="descname">_Py_NoneStruct</code><a class="headerlink" href="#c._Py_NoneStruct" title="Permalink to this definition">¶</a></dt>
<dd><p>Object which is visible in Python as <code class="docutils literal notranslate"><span class="pre">None</span></code>. This should only be
accessed using the <code class="docutils literal notranslate"><span class="pre">Py_None</span></code> macro, which evaluates to a pointer to this
object.</p>
</dd></dl>
</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="objimpl.html"
title="previous chapter">Object Implementation Support</a></p>
<h4>Next topic</h4>
<p class="topless"><a href="structures.html"
title="next chapter">Common Object Structures</a></p>
<div role="note" aria-label="source link">
<h3>This Page</h3>
<ul class="this-page-menu">
<li><a href="../_sources/c-api/allocation.rst.txt"
rel="nofollow">Show Source</a></li>
</ul>
</div>
<div id="searchbox" style="display: none" role="search">
<h3>Quick search</h3>
<div class="searchformwrapper">
<form class="search" action="../search.html" method="get">
<input type="text" name="q" />
<input type="submit" value="Go" />
</form>
</div>
</div>
<script type="text/javascript">$('#searchbox').show(0);</script>
</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="structures.html" title="Common Object Structures"
>next</a> |</li>
<li class="right" >
<a href="objimpl.html" title="Object Implementation Support"
>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">Python 2.7.17 documentation</a> »
</li>
<li class="nav-item nav-item-1"><a href="index.html" >Python/C API Reference Manual</a> »</li>
<li class="nav-item nav-item-2"><a href="objimpl.html" >Object Implementation Support</a> »</li>
</ul>
</div>
<div class="footer">
© <a href="../copyright.html">Copyright</a> 1990-2019, 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 Oct 19, 2019.
<a href="../bugs.html">Found a bug</a>?
<br />
Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 2.0.1.
</div>
</body>
</html>
distrib
>
Mageia
>
7
>
armv7hl
>
media
>
core-updates
>
by-pkgid
>
e1011ddec34cda34f3a002b121247943
>
files
>
523
