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  <section id="object-protocol">
<span id="object"></span><h1>Object Protocol<a class="headerlink" href="#object-protocol" title="Link to this heading">¶</a></h1>
<dl class="c function">
<dt class="sig sig-object c" id="c.Py_GetConstant">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">Py_GetConstant</span></span></span><span class="sig-paren">(</span><span class="kt"><span class="pre">unsigned</span></span><span class="w"> </span><span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">constant_id</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.Py_GetConstant" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a> since version 3.13.</em><p>Get a <a class="reference internal" href="../glossary.html#term-strong-reference"><span class="xref std std-term">strong reference</span></a> to a constant.</p>
<p>Set an exception and return <code class="docutils literal notranslate"><span class="pre">NULL</span></code> if <em>constant_id</em> is invalid.</p>
<p><em>constant_id</em> must be one of these constant identifiers:</p>
<table class="docutils align-default">
<thead>
<tr class="row-odd"><th class="head"><p>Constant Identifier</p></th>
<th class="head"><p>Value</p></th>
<th class="head"><p>Returned object</p></th>
</tr>
</thead>
<tbody>
<tr class="row-even"><td><dl class="c macro">
<dt class="sig sig-object c" id="c.Py_CONSTANT_NONE">
<span class="sig-name descname"><span class="n"><span class="pre">Py_CONSTANT_NONE</span></span></span><a class="headerlink" href="#c.Py_CONSTANT_NONE" title="Link to this definition">¶</a><br /></dt>
<dd></dd></dl>

</td>
<td><p><code class="docutils literal notranslate"><span class="pre">0</span></code></p></td>
<td><p><a class="reference internal" href="../library/constants.html#None" title="None"><code class="xref py py-data docutils literal notranslate"><span class="pre">None</span></code></a></p></td>
</tr>
<tr class="row-odd"><td><dl class="c macro">
<dt class="sig sig-object c" id="c.Py_CONSTANT_FALSE">
<span class="sig-name descname"><span class="n"><span class="pre">Py_CONSTANT_FALSE</span></span></span><a class="headerlink" href="#c.Py_CONSTANT_FALSE" title="Link to this definition">¶</a><br /></dt>
<dd></dd></dl>

</td>
<td><p><code class="docutils literal notranslate"><span class="pre">1</span></code></p></td>
<td><p><a class="reference internal" href="../library/constants.html#False" title="False"><code class="xref py py-data docutils literal notranslate"><span class="pre">False</span></code></a></p></td>
</tr>
<tr class="row-even"><td><dl class="c macro">
<dt class="sig sig-object c" id="c.Py_CONSTANT_TRUE">
<span class="sig-name descname"><span class="n"><span class="pre">Py_CONSTANT_TRUE</span></span></span><a class="headerlink" href="#c.Py_CONSTANT_TRUE" title="Link to this definition">¶</a><br /></dt>
<dd></dd></dl>

</td>
<td><p><code class="docutils literal notranslate"><span class="pre">2</span></code></p></td>
<td><p><a class="reference internal" href="../library/constants.html#True" title="True"><code class="xref py py-data docutils literal notranslate"><span class="pre">True</span></code></a></p></td>
</tr>
<tr class="row-odd"><td><dl class="c macro">
<dt class="sig sig-object c" id="c.Py_CONSTANT_ELLIPSIS">
<span class="sig-name descname"><span class="n"><span class="pre">Py_CONSTANT_ELLIPSIS</span></span></span><a class="headerlink" href="#c.Py_CONSTANT_ELLIPSIS" title="Link to this definition">¶</a><br /></dt>
<dd></dd></dl>

</td>
<td><p><code class="docutils literal notranslate"><span class="pre">3</span></code></p></td>
<td><p><a class="reference internal" href="../library/constants.html#Ellipsis" title="Ellipsis"><code class="xref py py-data docutils literal notranslate"><span class="pre">Ellipsis</span></code></a></p></td>
</tr>
<tr class="row-even"><td><dl class="c macro">
<dt class="sig sig-object c" id="c.Py_CONSTANT_NOT_IMPLEMENTED">
<span class="sig-name descname"><span class="n"><span class="pre">Py_CONSTANT_NOT_IMPLEMENTED</span></span></span><a class="headerlink" href="#c.Py_CONSTANT_NOT_IMPLEMENTED" title="Link to this definition">¶</a><br /></dt>
<dd></dd></dl>

</td>
<td><p><code class="docutils literal notranslate"><span class="pre">4</span></code></p></td>
<td><p><a class="reference internal" href="../library/constants.html#NotImplemented" title="NotImplemented"><code class="xref py py-data docutils literal notranslate"><span class="pre">NotImplemented</span></code></a></p></td>
</tr>
<tr class="row-odd"><td><dl class="c macro">
<dt class="sig sig-object c" id="c.Py_CONSTANT_ZERO">
<span class="sig-name descname"><span class="n"><span class="pre">Py_CONSTANT_ZERO</span></span></span><a class="headerlink" href="#c.Py_CONSTANT_ZERO" title="Link to this definition">¶</a><br /></dt>
<dd></dd></dl>

</td>
<td><p><code class="docutils literal notranslate"><span class="pre">5</span></code></p></td>
<td><p><code class="docutils literal notranslate"><span class="pre">0</span></code></p></td>
</tr>
<tr class="row-even"><td><dl class="c macro">
<dt class="sig sig-object c" id="c.Py_CONSTANT_ONE">
<span class="sig-name descname"><span class="n"><span class="pre">Py_CONSTANT_ONE</span></span></span><a class="headerlink" href="#c.Py_CONSTANT_ONE" title="Link to this definition">¶</a><br /></dt>
<dd></dd></dl>

</td>
<td><p><code class="docutils literal notranslate"><span class="pre">6</span></code></p></td>
<td><p><code class="docutils literal notranslate"><span class="pre">1</span></code></p></td>
</tr>
<tr class="row-odd"><td><dl class="c macro">
<dt class="sig sig-object c" id="c.Py_CONSTANT_EMPTY_STR">
<span class="sig-name descname"><span class="n"><span class="pre">Py_CONSTANT_EMPTY_STR</span></span></span><a class="headerlink" href="#c.Py_CONSTANT_EMPTY_STR" title="Link to this definition">¶</a><br /></dt>
<dd></dd></dl>

</td>
<td><p><code class="docutils literal notranslate"><span class="pre">7</span></code></p></td>
<td><p><code class="docutils literal notranslate"><span class="pre">''</span></code></p></td>
</tr>
<tr class="row-even"><td><dl class="c macro">
<dt class="sig sig-object c" id="c.Py_CONSTANT_EMPTY_BYTES">
<span class="sig-name descname"><span class="n"><span class="pre">Py_CONSTANT_EMPTY_BYTES</span></span></span><a class="headerlink" href="#c.Py_CONSTANT_EMPTY_BYTES" title="Link to this definition">¶</a><br /></dt>
<dd></dd></dl>

</td>
<td><p><code class="docutils literal notranslate"><span class="pre">8</span></code></p></td>
<td><p><code class="docutils literal notranslate"><span class="pre">b''</span></code></p></td>
</tr>
<tr class="row-odd"><td><dl class="c macro">
<dt class="sig sig-object c" id="c.Py_CONSTANT_EMPTY_TUPLE">
<span class="sig-name descname"><span class="n"><span class="pre">Py_CONSTANT_EMPTY_TUPLE</span></span></span><a class="headerlink" href="#c.Py_CONSTANT_EMPTY_TUPLE" title="Link to this definition">¶</a><br /></dt>
<dd></dd></dl>

</td>
<td><p><code class="docutils literal notranslate"><span class="pre">9</span></code></p></td>
<td><p><code class="docutils literal notranslate"><span class="pre">()</span></code></p></td>
</tr>
</tbody>
</table>
<p>Numeric values are only given for projects which cannot use the constant
identifiers.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.13.</span></p>
</div>
<div class="impl-detail compound">
<p><strong>CPython implementation detail:</strong> In CPython, all of these constants are <a class="reference internal" href="../glossary.html#term-immortal"><span class="xref std std-term">immortal</span></a>.</p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.Py_GetConstantBorrowed">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">Py_GetConstantBorrowed</span></span></span><span class="sig-paren">(</span><span class="kt"><span class="pre">unsigned</span></span><span class="w"> </span><span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">constant_id</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.Py_GetConstantBorrowed" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a> since version 3.13.</em><p>Similar to <a class="reference internal" href="#c.Py_GetConstant" title="Py_GetConstant"><code class="xref c c-func docutils literal notranslate"><span class="pre">Py_GetConstant()</span></code></a>, but return a <a class="reference internal" href="../glossary.html#term-borrowed-reference"><span class="xref std std-term">borrowed
reference</span></a>.</p>
<p>This function is primarily intended for backwards compatibility:
using <a class="reference internal" href="#c.Py_GetConstant" title="Py_GetConstant"><code class="xref c c-func docutils literal notranslate"><span class="pre">Py_GetConstant()</span></code></a> is recommended for new code.</p>
<p>The reference is borrowed from the interpreter, and is valid until the
interpreter finalization.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.13.</span></p>
</div>
</dd></dl>

<dl class="c var">
<dt class="sig sig-object c" id="c.Py_NotImplemented">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">Py_NotImplemented</span></span></span><a class="headerlink" href="#c.Py_NotImplemented" title="Link to this definition">¶</a><br /></dt>
<dd><p>The <code class="docutils literal notranslate"><span class="pre">NotImplemented</span></code> singleton, used to signal that an operation is
not implemented for the given type combination.</p>
</dd></dl>

<dl class="c macro">
<dt class="sig sig-object c" id="c.Py_RETURN_NOTIMPLEMENTED">
<span class="sig-name descname"><span class="n"><span class="pre">Py_RETURN_NOTIMPLEMENTED</span></span></span><a class="headerlink" href="#c.Py_RETURN_NOTIMPLEMENTED" title="Link to this definition">¶</a><br /></dt>
<dd><p>Properly handle returning <a class="reference internal" href="#c.Py_NotImplemented" title="Py_NotImplemented"><code class="xref c c-data docutils literal notranslate"><span class="pre">Py_NotImplemented</span></code></a> from within a C
function (that is, create a new <a class="reference internal" href="../glossary.html#term-strong-reference"><span class="xref std std-term">strong reference</span></a>
to <a class="reference internal" href="../library/constants.html#NotImplemented" title="NotImplemented"><code class="xref py py-const docutils literal notranslate"><span class="pre">NotImplemented</span></code></a> and return it).</p>
</dd></dl>

<dl class="c macro">
<dt class="sig sig-object c" id="c.Py_PRINT_RAW">
<span class="sig-name descname"><span class="n"><span class="pre">Py_PRINT_RAW</span></span></span><a class="headerlink" href="#c.Py_PRINT_RAW" title="Link to this definition">¶</a><br /></dt>
<dd><p>Flag to be used with multiple functions that print the object (like
<a class="reference internal" href="#c.PyObject_Print" title="PyObject_Print"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_Print()</span></code></a> and <a class="reference internal" href="file.html#c.PyFile_WriteObject" title="PyFile_WriteObject"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyFile_WriteObject()</span></code></a>).
If passed, these functions use the <a class="reference internal" href="../library/stdtypes.html#str" title="str"><code class="xref py py-func docutils literal notranslate"><span class="pre">str()</span></code></a> of the object
instead of the <a class="reference internal" href="../library/functions.html#repr" title="repr"><code class="xref py py-func docutils literal notranslate"><span class="pre">repr()</span></code></a>.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_Print">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_Print</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <span class="n"><span class="pre">FILE</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">fp</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">flags</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_Print" title="Link to this definition">¶</a><br /></dt>
<dd><p>Print an object <em>o</em>, on file <em>fp</em>.  Returns <code class="docutils literal notranslate"><span class="pre">-1</span></code> on error.  The flags argument
is used to enable certain printing options.  The only option currently supported
is <a class="reference internal" href="#c.Py_PRINT_RAW" title="Py_PRINT_RAW"><code class="xref c c-macro docutils literal notranslate"><span class="pre">Py_PRINT_RAW</span></code></a>; if given, the <a class="reference internal" href="../library/stdtypes.html#str" title="str"><code class="xref py py-func docutils literal notranslate"><span class="pre">str()</span></code></a> of the object is written
instead of the <a class="reference internal" href="../library/functions.html#repr" title="repr"><code class="xref py py-func docutils literal notranslate"><span class="pre">repr()</span></code></a>.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_HasAttrWithError">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_HasAttrWithError</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">attr_name</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_HasAttrWithError" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a> since version 3.13.</em><p>Returns <code class="docutils literal notranslate"><span class="pre">1</span></code> if <em>o</em> has the attribute <em>attr_name</em>, and <code class="docutils literal notranslate"><span class="pre">0</span></code> otherwise.
This is equivalent to the Python expression <code class="docutils literal notranslate"><span class="pre">hasattr(o,</span> <span class="pre">attr_name)</span></code>.
On failure, return <code class="docutils literal notranslate"><span class="pre">-1</span></code>.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.13.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_HasAttrStringWithError">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_HasAttrStringWithError</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <span class="k"><span class="pre">const</span></span><span class="w"> </span><span class="kt"><span class="pre">char</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">attr_name</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_HasAttrStringWithError" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a> since version 3.13.</em><p>This is the same as <a class="reference internal" href="#c.PyObject_HasAttrWithError" title="PyObject_HasAttrWithError"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_HasAttrWithError()</span></code></a>, but <em>attr_name</em> is
specified as a <span class="c-expr sig sig-inline c"><span class="k">const</span><span class="w"> </span><span class="kt">char</span><span class="p">*</span></span> UTF-8 encoded bytes string,
rather than a <span class="c-expr sig sig-inline c"><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n">PyObject</span></a><span class="p">*</span></span>.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.13.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_HasAttr">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_HasAttr</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">attr_name</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_HasAttr" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>Returns <code class="docutils literal notranslate"><span class="pre">1</span></code> if <em>o</em> has the attribute <em>attr_name</em>, and <code class="docutils literal notranslate"><span class="pre">0</span></code> otherwise.
This function always succeeds.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>Exceptions that occur when this calls <a class="reference internal" href="../reference/datamodel.html#object.__getattr__" title="object.__getattr__"><code class="xref py py-meth docutils literal notranslate"><span class="pre">__getattr__()</span></code></a> and
<a class="reference internal" href="../reference/datamodel.html#object.__getattribute__" title="object.__getattribute__"><code class="xref py py-meth docutils literal notranslate"><span class="pre">__getattribute__()</span></code></a> methods aren’t propagated,
but instead given to <a class="reference internal" href="../library/sys.html#sys.unraisablehook" title="sys.unraisablehook"><code class="xref py py-func docutils literal notranslate"><span class="pre">sys.unraisablehook()</span></code></a>.
For proper error handling, use <a class="reference internal" href="#c.PyObject_HasAttrWithError" title="PyObject_HasAttrWithError"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_HasAttrWithError()</span></code></a>,
<a class="reference internal" href="#c.PyObject_GetOptionalAttr" title="PyObject_GetOptionalAttr"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_GetOptionalAttr()</span></code></a> or <a class="reference internal" href="#c.PyObject_GetAttr" title="PyObject_GetAttr"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_GetAttr()</span></code></a> instead.</p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_HasAttrString">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_HasAttrString</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <span class="k"><span class="pre">const</span></span><span class="w"> </span><span class="kt"><span class="pre">char</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">attr_name</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_HasAttrString" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>This is the same as <a class="reference internal" href="#c.PyObject_HasAttr" title="PyObject_HasAttr"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_HasAttr()</span></code></a>, but <em>attr_name</em> is
specified as a <span class="c-expr sig sig-inline c"><span class="k">const</span><span class="w"> </span><span class="kt">char</span><span class="p">*</span></span> UTF-8 encoded bytes string,
rather than a <span class="c-expr sig sig-inline c"><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n">PyObject</span></a><span class="p">*</span></span>.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>Exceptions that occur when this calls <a class="reference internal" href="../reference/datamodel.html#object.__getattr__" title="object.__getattr__"><code class="xref py py-meth docutils literal notranslate"><span class="pre">__getattr__()</span></code></a> and
<a class="reference internal" href="../reference/datamodel.html#object.__getattribute__" title="object.__getattribute__"><code class="xref py py-meth docutils literal notranslate"><span class="pre">__getattribute__()</span></code></a> methods or while creating the temporary
<a class="reference internal" href="../library/stdtypes.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a> object are silently ignored.
For proper error handling, use <a class="reference internal" href="#c.PyObject_HasAttrStringWithError" title="PyObject_HasAttrStringWithError"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_HasAttrStringWithError()</span></code></a>,
<a class="reference internal" href="#c.PyObject_GetOptionalAttrString" title="PyObject_GetOptionalAttrString"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_GetOptionalAttrString()</span></code></a>
or <a class="reference internal" href="#c.PyObject_GetAttrString" title="PyObject_GetAttrString"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_GetAttrString()</span></code></a> instead.</p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_GetAttr">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_GetAttr</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">attr_name</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_GetAttr" title="Link to this definition">¶</a><br /></dt>
<dd><em class="refcount return_new_ref">Return value: New reference.</em><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>Retrieve an attribute named <em>attr_name</em> from object <em>o</em>. Returns the attribute
value on success, or <code class="docutils literal notranslate"><span class="pre">NULL</span></code> on failure.  This is the equivalent of the Python
expression <code class="docutils literal notranslate"><span class="pre">o.attr_name</span></code>.</p>
<p>If the missing attribute should not be treated as a failure, you can use
<a class="reference internal" href="#c.PyObject_GetOptionalAttr" title="PyObject_GetOptionalAttr"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_GetOptionalAttr()</span></code></a> instead.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_GetAttrString">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_GetAttrString</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <span class="k"><span class="pre">const</span></span><span class="w"> </span><span class="kt"><span class="pre">char</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">attr_name</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_GetAttrString" title="Link to this definition">¶</a><br /></dt>
<dd><em class="refcount return_new_ref">Return value: New reference.</em><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>This is the same as <a class="reference internal" href="#c.PyObject_GetAttr" title="PyObject_GetAttr"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_GetAttr()</span></code></a>, but <em>attr_name</em> is
specified as a <span class="c-expr sig sig-inline c"><span class="k">const</span><span class="w"> </span><span class="kt">char</span><span class="p">*</span></span> UTF-8 encoded bytes string,
rather than a <span class="c-expr sig sig-inline c"><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n">PyObject</span></a><span class="p">*</span></span>.</p>
<p>If the missing attribute should not be treated as a failure, you can use
<a class="reference internal" href="#c.PyObject_GetOptionalAttrString" title="PyObject_GetOptionalAttrString"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_GetOptionalAttrString()</span></code></a> instead.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_GetOptionalAttr">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_GetOptionalAttr</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">obj</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">attr_name</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">result</span></span><span class="sig-paren">)</span><span class="p"><span class="pre">;</span></span><a class="headerlink" href="#c.PyObject_GetOptionalAttr" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a> since version 3.13.</em><p>Variant of <a class="reference internal" href="#c.PyObject_GetAttr" title="PyObject_GetAttr"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_GetAttr()</span></code></a> which doesn’t raise
<a class="reference internal" href="../library/exceptions.html#AttributeError" title="AttributeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">AttributeError</span></code></a> if the attribute is not found.</p>
<p>If the attribute is found, return <code class="docutils literal notranslate"><span class="pre">1</span></code> and set <em>*result</em> to a new
<a class="reference internal" href="../glossary.html#term-strong-reference"><span class="xref std std-term">strong reference</span></a> to the attribute.
If the attribute is not found, return <code class="docutils literal notranslate"><span class="pre">0</span></code> and set <em>*result</em> to <code class="docutils literal notranslate"><span class="pre">NULL</span></code>;
the <a class="reference internal" href="../library/exceptions.html#AttributeError" title="AttributeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">AttributeError</span></code></a> is silenced.
If an error other than <code class="xref py py-exc docutils literal notranslate"><span class="pre">AttributeError</span></code> is raised, return <code class="docutils literal notranslate"><span class="pre">-1</span></code> and
set <em>*result</em> to <code class="docutils literal notranslate"><span class="pre">NULL</span></code>.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.13.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_GetOptionalAttrString">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_GetOptionalAttrString</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">obj</span></span>, <span class="k"><span class="pre">const</span></span><span class="w"> </span><span class="kt"><span class="pre">char</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">attr_name</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">result</span></span><span class="sig-paren">)</span><span class="p"><span class="pre">;</span></span><a class="headerlink" href="#c.PyObject_GetOptionalAttrString" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a> since version 3.13.</em><p>This is the same as <a class="reference internal" href="#c.PyObject_GetOptionalAttr" title="PyObject_GetOptionalAttr"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_GetOptionalAttr()</span></code></a>, but <em>attr_name</em> is
specified as a <span class="c-expr sig sig-inline c"><span class="k">const</span><span class="w"> </span><span class="kt">char</span><span class="p">*</span></span> UTF-8 encoded bytes string,
rather than a <span class="c-expr sig sig-inline c"><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n">PyObject</span></a><span class="p">*</span></span>.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.13.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_GenericGetAttr">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_GenericGetAttr</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">name</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_GenericGetAttr" title="Link to this definition">¶</a><br /></dt>
<dd><em class="refcount return_new_ref">Return value: New reference.</em><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>Generic attribute getter function that is meant to be put into a type
object’s <code class="docutils literal notranslate"><span class="pre">tp_getattro</span></code> slot.  It looks for a descriptor in the dictionary
of classes in the object’s MRO as well as an attribute in the object’s
<a class="reference internal" href="../reference/datamodel.html#object.__dict__" title="object.__dict__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__dict__</span></code></a> (if present).  As outlined in <a class="reference internal" href="../reference/datamodel.html#descriptors"><span class="std std-ref">Implementing Descriptors</span></a>,
data descriptors take preference over instance attributes, while non-data
descriptors don’t.  Otherwise, an <a class="reference internal" href="../library/exceptions.html#AttributeError" title="AttributeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">AttributeError</span></code></a> is raised.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_SetAttr">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_SetAttr</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">attr_name</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">v</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_SetAttr" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>Set the value of the attribute named <em>attr_name</em>, for object <em>o</em>, to the value
<em>v</em>. Raise an exception and return <code class="docutils literal notranslate"><span class="pre">-1</span></code> on failure;
return <code class="docutils literal notranslate"><span class="pre">0</span></code> on success.  This is the equivalent of the Python statement
<code class="docutils literal notranslate"><span class="pre">o.attr_name</span> <span class="pre">=</span> <span class="pre">v</span></code>.</p>
<p>If <em>v</em> is <code class="docutils literal notranslate"><span class="pre">NULL</span></code>, the attribute is deleted. This behaviour is deprecated
in favour of using <a class="reference internal" href="#c.PyObject_DelAttr" title="PyObject_DelAttr"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_DelAttr()</span></code></a>, but there are currently no
plans to remove it.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_SetAttrString">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_SetAttrString</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <span class="k"><span class="pre">const</span></span><span class="w"> </span><span class="kt"><span class="pre">char</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">attr_name</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">v</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_SetAttrString" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>This is the same as <a class="reference internal" href="#c.PyObject_SetAttr" title="PyObject_SetAttr"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_SetAttr()</span></code></a>, but <em>attr_name</em> is
specified as a <span class="c-expr sig sig-inline c"><span class="k">const</span><span class="w"> </span><span class="kt">char</span><span class="p">*</span></span> UTF-8 encoded bytes string,
rather than a <span class="c-expr sig sig-inline c"><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n">PyObject</span></a><span class="p">*</span></span>.</p>
<p>If <em>v</em> is <code class="docutils literal notranslate"><span class="pre">NULL</span></code>, the attribute is deleted, but this feature is
deprecated in favour of using <a class="reference internal" href="#c.PyObject_DelAttrString" title="PyObject_DelAttrString"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_DelAttrString()</span></code></a>.</p>
<p>The number of different attribute names passed to this function
should be kept small, usually by using a statically allocated string
as <em>attr_name</em>.
For attribute names that aren’t known at compile time, prefer calling
<a class="reference internal" href="unicode.html#c.PyUnicode_FromString" title="PyUnicode_FromString"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyUnicode_FromString()</span></code></a> and <a class="reference internal" href="#c.PyObject_SetAttr" title="PyObject_SetAttr"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_SetAttr()</span></code></a> directly.
For more details, see <a class="reference internal" href="unicode.html#c.PyUnicode_InternFromString" title="PyUnicode_InternFromString"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyUnicode_InternFromString()</span></code></a>, which may be
used internally to create a key object.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_GenericSetAttr">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_GenericSetAttr</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">name</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">value</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_GenericSetAttr" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>Generic attribute setter and deleter function that is meant
to be put into a type object’s <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_setattro" title="PyTypeObject.tp_setattro"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_setattro</span></code></a>
slot.  It looks for a data descriptor in the
dictionary of classes in the object’s MRO, and if found it takes preference
over setting or deleting the attribute in the instance dictionary. Otherwise, the
attribute is set or deleted in the object’s <a class="reference internal" href="../reference/datamodel.html#object.__dict__" title="object.__dict__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__dict__</span></code></a> (if present).
On success, <code class="docutils literal notranslate"><span class="pre">0</span></code> is returned, otherwise an <a class="reference internal" href="../library/exceptions.html#AttributeError" title="AttributeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">AttributeError</span></code></a>
is raised and <code class="docutils literal notranslate"><span class="pre">-1</span></code> is returned.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_DelAttr">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_DelAttr</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">attr_name</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_DelAttr" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a> since version 3.13.</em><p>Delete attribute named <em>attr_name</em>, for object <em>o</em>. Returns <code class="docutils literal notranslate"><span class="pre">-1</span></code> on failure.
This is the equivalent of the Python statement <code class="docutils literal notranslate"><span class="pre">del</span> <span class="pre">o.attr_name</span></code>.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_DelAttrString">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_DelAttrString</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <span class="k"><span class="pre">const</span></span><span class="w"> </span><span class="kt"><span class="pre">char</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">attr_name</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_DelAttrString" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a> since version 3.13.</em><p>This is the same as <a class="reference internal" href="#c.PyObject_DelAttr" title="PyObject_DelAttr"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_DelAttr()</span></code></a>, but <em>attr_name</em> is
specified as a <span class="c-expr sig sig-inline c"><span class="k">const</span><span class="w"> </span><span class="kt">char</span><span class="p">*</span></span> UTF-8 encoded bytes string,
rather than a <span class="c-expr sig sig-inline c"><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n">PyObject</span></a><span class="p">*</span></span>.</p>
<p>The number of different attribute names passed to this function
should be kept small, usually by using a statically allocated string
as <em>attr_name</em>.
For attribute names that aren’t known at compile time, prefer calling
<a class="reference internal" href="unicode.html#c.PyUnicode_FromString" title="PyUnicode_FromString"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyUnicode_FromString()</span></code></a> and <a class="reference internal" href="#c.PyObject_DelAttr" title="PyObject_DelAttr"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_DelAttr()</span></code></a> directly.
For more details, see <a class="reference internal" href="unicode.html#c.PyUnicode_InternFromString" title="PyUnicode_InternFromString"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyUnicode_InternFromString()</span></code></a>, which may be
used internally to create a key object for lookup.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_GenericGetDict">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_GenericGetDict</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <span class="kt"><span class="pre">void</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">context</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_GenericGetDict" title="Link to this definition">¶</a><br /></dt>
<dd><em class="refcount return_new_ref">Return value: New reference.</em><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a> since version 3.10.</em><p>A generic implementation for the getter of a <code class="docutils literal notranslate"><span class="pre">__dict__</span></code> descriptor. It
creates the dictionary if necessary.</p>
<p>This function may also be called to get the <a class="reference internal" href="../reference/datamodel.html#object.__dict__" title="object.__dict__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__dict__</span></code></a>
of the object <em>o</em>. Pass <code class="docutils literal notranslate"><span class="pre">NULL</span></code> for <em>context</em> when calling it.
Since this function may need to allocate memory for the
dictionary, it may be more efficient to call <a class="reference internal" href="#c.PyObject_GetAttr" title="PyObject_GetAttr"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_GetAttr()</span></code></a>
when accessing an attribute on the object.</p>
<p>On failure, returns <code class="docutils literal notranslate"><span class="pre">NULL</span></code> with an exception set.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.3.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_GenericSetDict">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_GenericSetDict</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">value</span></span>, <span class="kt"><span class="pre">void</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">context</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_GenericSetDict" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a> since version 3.7.</em><p>A generic implementation for the setter of a <code class="docutils literal notranslate"><span class="pre">__dict__</span></code> descriptor. This
implementation does not allow the dictionary to be deleted.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.3.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c._PyObject_GetDictPtr">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">_PyObject_GetDictPtr</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">obj</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c._PyObject_GetDictPtr" title="Link to this definition">¶</a><br /></dt>
<dd><p>Return a pointer to <a class="reference internal" href="../reference/datamodel.html#object.__dict__" title="object.__dict__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__dict__</span></code></a> of the object <em>obj</em>.
If there is no <code class="docutils literal notranslate"><span class="pre">__dict__</span></code>, return <code class="docutils literal notranslate"><span class="pre">NULL</span></code> without setting an exception.</p>
<p>This function may need to allocate memory for the
dictionary, so it may be more efficient to call <a class="reference internal" href="#c.PyObject_GetAttr" title="PyObject_GetAttr"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_GetAttr()</span></code></a>
when accessing an attribute on the object.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_RichCompare">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_RichCompare</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o1</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o2</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">opid</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_RichCompare" title="Link to this definition">¶</a><br /></dt>
<dd><em class="refcount return_new_ref">Return value: New reference.</em><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>Compare the values of <em>o1</em> and <em>o2</em> using the operation specified by <em>opid</em>,
which must be one of <a class="reference internal" href="typeobj.html#c.Py_LT" title="Py_LT"><code class="xref c c-macro docutils literal notranslate"><span class="pre">Py_LT</span></code></a>, <a class="reference internal" href="typeobj.html#c.Py_LE" title="Py_LE"><code class="xref c c-macro docutils literal notranslate"><span class="pre">Py_LE</span></code></a>, <a class="reference internal" href="typeobj.html#c.Py_EQ" title="Py_EQ"><code class="xref c c-macro docutils literal notranslate"><span class="pre">Py_EQ</span></code></a>,
<a class="reference internal" href="typeobj.html#c.Py_NE" title="Py_NE"><code class="xref c c-macro docutils literal notranslate"><span class="pre">Py_NE</span></code></a>, <a class="reference internal" href="typeobj.html#c.Py_GT" title="Py_GT"><code class="xref c c-macro docutils literal notranslate"><span class="pre">Py_GT</span></code></a>, or <a class="reference internal" href="typeobj.html#c.Py_GE" title="Py_GE"><code class="xref c c-macro docutils literal notranslate"><span class="pre">Py_GE</span></code></a>, corresponding to <code class="docutils literal notranslate"><span class="pre">&lt;</span></code>,
<code class="docutils literal notranslate"><span class="pre">&lt;=</span></code>, <code class="docutils literal notranslate"><span class="pre">==</span></code>, <code class="docutils literal notranslate"><span class="pre">!=</span></code>, <code class="docutils literal notranslate"><span class="pre">&gt;</span></code>, or <code class="docutils literal notranslate"><span class="pre">&gt;=</span></code> respectively. This is the equivalent of
the Python expression <code class="docutils literal notranslate"><span class="pre">o1</span> <span class="pre">op</span> <span class="pre">o2</span></code>, where <code class="docutils literal notranslate"><span class="pre">op</span></code> is the operator corresponding
to <em>opid</em>. Returns the value of the comparison on success, or <code class="docutils literal notranslate"><span class="pre">NULL</span></code> on failure.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_RichCompareBool">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_RichCompareBool</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o1</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o2</span></span>, <span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="n"><span class="pre">opid</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_RichCompareBool" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>Compare the values of <em>o1</em> and <em>o2</em> using the operation specified by <em>opid</em>,
like <a class="reference internal" href="#c.PyObject_RichCompare" title="PyObject_RichCompare"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_RichCompare()</span></code></a>, but returns <code class="docutils literal notranslate"><span class="pre">-1</span></code> on error, <code class="docutils literal notranslate"><span class="pre">0</span></code> if
the result is false, <code class="docutils literal notranslate"><span class="pre">1</span></code> otherwise.</p>
</dd></dl>

<div class="admonition note">
<p class="admonition-title">Note</p>
<p>If <em>o1</em> and <em>o2</em> are the same object, <a class="reference internal" href="#c.PyObject_RichCompareBool" title="PyObject_RichCompareBool"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_RichCompareBool()</span></code></a>
will always return <code class="docutils literal notranslate"><span class="pre">1</span></code> for <a class="reference internal" href="typeobj.html#c.Py_EQ" title="Py_EQ"><code class="xref c c-macro docutils literal notranslate"><span class="pre">Py_EQ</span></code></a> and <code class="docutils literal notranslate"><span class="pre">0</span></code> for <a class="reference internal" href="typeobj.html#c.Py_NE" title="Py_NE"><code class="xref c c-macro docutils literal notranslate"><span class="pre">Py_NE</span></code></a>.</p>
</div>
<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_Format">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_Format</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">obj</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">format_spec</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_Format" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>Format <em>obj</em> using <em>format_spec</em>. This is equivalent to the Python
expression <code class="docutils literal notranslate"><span class="pre">format(obj,</span> <span class="pre">format_spec)</span></code>.</p>
<p><em>format_spec</em> may be <code class="docutils literal notranslate"><span class="pre">NULL</span></code>. In this case the call is equivalent
to <code class="docutils literal notranslate"><span class="pre">format(obj)</span></code>.
Returns the formatted string on success, <code class="docutils literal notranslate"><span class="pre">NULL</span></code> on failure.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_Repr">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_Repr</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_Repr" title="Link to this definition">¶</a><br /></dt>
<dd><em class="refcount return_new_ref">Return value: New reference.</em><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p id="index-0">Compute a string representation of object <em>o</em>.  Returns the string
representation on success, <code class="docutils literal notranslate"><span class="pre">NULL</span></code> on failure.  This is the equivalent of the
Python expression <code class="docutils literal notranslate"><span class="pre">repr(o)</span></code>.  Called by the <a class="reference internal" href="../library/functions.html#repr" title="repr"><code class="xref py py-func docutils literal notranslate"><span class="pre">repr()</span></code></a> built-in function.</p>
<p>If argument is <code class="docutils literal notranslate"><span class="pre">NULL</span></code>, return the string <code class="docutils literal notranslate"><span class="pre">'&lt;NULL&gt;'</span></code>.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>This function now includes a debug assertion to help ensure that it
does not silently discard an active exception.</p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_ASCII">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_ASCII</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_ASCII" title="Link to this definition">¶</a><br /></dt>
<dd><em class="refcount return_new_ref">Return value: New reference.</em><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p id="index-1">As <a class="reference internal" href="#c.PyObject_Repr" title="PyObject_Repr"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_Repr()</span></code></a>, compute a string representation of object <em>o</em>, but
escape the non-ASCII characters in the string returned by
<code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_Repr()</span></code> with <code class="docutils literal notranslate"><span class="pre">\x</span></code>, <code class="docutils literal notranslate"><span class="pre">\u</span></code> or <code class="docutils literal notranslate"><span class="pre">\U</span></code> escapes.  This generates
a string similar to that returned by <code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_Repr()</span></code> in Python 2.
Called by the <a class="reference internal" href="../library/functions.html#ascii" title="ascii"><code class="xref py py-func docutils literal notranslate"><span class="pre">ascii()</span></code></a> built-in function.</p>
<p>If argument is <code class="docutils literal notranslate"><span class="pre">NULL</span></code>, return the string <code class="docutils literal notranslate"><span class="pre">'&lt;NULL&gt;'</span></code>.</p>
<span class="target" id="index-2"></span></dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_Str">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_Str</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_Str" title="Link to this definition">¶</a><br /></dt>
<dd><em class="refcount return_new_ref">Return value: New reference.</em><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>Compute a string representation of object <em>o</em>.  Returns the string
representation on success, <code class="docutils literal notranslate"><span class="pre">NULL</span></code> on failure.  This is the equivalent of the
Python expression <code class="docutils literal notranslate"><span class="pre">str(o)</span></code>.  Called by the <a class="reference internal" href="../library/stdtypes.html#str" title="str"><code class="xref py py-func docutils literal notranslate"><span class="pre">str()</span></code></a> built-in function
and, therefore, by the <a class="reference internal" href="../library/functions.html#print" title="print"><code class="xref py py-func docutils literal notranslate"><span class="pre">print()</span></code></a> function.</p>
<p>If argument is <code class="docutils literal notranslate"><span class="pre">NULL</span></code>, return the string <code class="docutils literal notranslate"><span class="pre">'&lt;NULL&gt;'</span></code>.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>This function now includes a debug assertion to help ensure that it
does not silently discard an active exception.</p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_Bytes">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_Bytes</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_Bytes" title="Link to this definition">¶</a><br /></dt>
<dd><em class="refcount return_new_ref">Return value: New reference.</em><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p id="index-3">Compute a bytes representation of object <em>o</em>.  <code class="docutils literal notranslate"><span class="pre">NULL</span></code> is returned on
failure and a bytes object on success.  This is equivalent to the Python
expression <code class="docutils literal notranslate"><span class="pre">bytes(o)</span></code>, when <em>o</em> is not an integer.  Unlike <code class="docutils literal notranslate"><span class="pre">bytes(o)</span></code>,
a TypeError is raised when <em>o</em> is an integer instead of a zero-initialized
bytes object.</p>
<p>If argument is <code class="docutils literal notranslate"><span class="pre">NULL</span></code>, return the <a class="reference internal" href="../library/stdtypes.html#bytes" title="bytes"><code class="xref py py-class docutils literal notranslate"><span class="pre">bytes</span></code></a> object <code class="docutils literal notranslate"><span class="pre">b'&lt;NULL&gt;'</span></code>.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_IsSubclass">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_IsSubclass</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">derived</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">cls</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_IsSubclass" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>Return <code class="docutils literal notranslate"><span class="pre">1</span></code> if the class <em>derived</em> is identical to or derived from the class
<em>cls</em>, otherwise return <code class="docutils literal notranslate"><span class="pre">0</span></code>.  In case of an error, return <code class="docutils literal notranslate"><span class="pre">-1</span></code>.</p>
<p>If <em>cls</em> is a tuple, the check will be done against every entry in <em>cls</em>.
The result will be <code class="docutils literal notranslate"><span class="pre">1</span></code> when at least one of the checks returns <code class="docutils literal notranslate"><span class="pre">1</span></code>,
otherwise it will be <code class="docutils literal notranslate"><span class="pre">0</span></code>.</p>
<p>If <em>cls</em> has a <a class="reference internal" href="../reference/datamodel.html#type.__subclasscheck__" title="type.__subclasscheck__"><code class="xref py py-meth docutils literal notranslate"><span class="pre">__subclasscheck__()</span></code></a> method, it will be called to
determine the subclass status as described in <span class="target" id="index-4"></span><a class="pep reference external" href="https://peps.python.org/pep-3119/"><strong>PEP 3119</strong></a>.  Otherwise,
<em>derived</em> is a subclass of <em>cls</em> if it is a direct or indirect subclass,
i.e. contained in <a class="reference internal" href="../reference/datamodel.html#type.__mro__" title="type.__mro__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">cls.__mro__</span></code></a>.</p>
<p>Normally only class objects, i.e. instances of <a class="reference internal" href="../library/functions.html#type" title="type"><code class="xref py py-class docutils literal notranslate"><span class="pre">type</span></code></a> or a derived
class, are considered classes.  However, objects can override this by having
a <a class="reference internal" href="../reference/datamodel.html#type.__bases__" title="type.__bases__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__bases__</span></code></a> attribute (which must be a tuple of base classes).</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_IsInstance">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_IsInstance</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">inst</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">cls</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_IsInstance" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>Return <code class="docutils literal notranslate"><span class="pre">1</span></code> if <em>inst</em> is an instance of the class <em>cls</em> or a subclass of
<em>cls</em>, or <code class="docutils literal notranslate"><span class="pre">0</span></code> if not.  On error, returns <code class="docutils literal notranslate"><span class="pre">-1</span></code> and sets an exception.</p>
<p>If <em>cls</em> is a tuple, the check will be done against every entry in <em>cls</em>.
The result will be <code class="docutils literal notranslate"><span class="pre">1</span></code> when at least one of the checks returns <code class="docutils literal notranslate"><span class="pre">1</span></code>,
otherwise it will be <code class="docutils literal notranslate"><span class="pre">0</span></code>.</p>
<p>If <em>cls</em> has a <a class="reference internal" href="../reference/datamodel.html#type.__instancecheck__" title="type.__instancecheck__"><code class="xref py py-meth docutils literal notranslate"><span class="pre">__instancecheck__()</span></code></a> method, it will be called to
determine the subclass status as described in <span class="target" id="index-5"></span><a class="pep reference external" href="https://peps.python.org/pep-3119/"><strong>PEP 3119</strong></a>.  Otherwise, <em>inst</em>
is an instance of <em>cls</em> if its class is a subclass of <em>cls</em>.</p>
<p>An instance <em>inst</em> can override what is considered its class by having a
<a class="reference internal" href="../reference/datamodel.html#object.__class__" title="object.__class__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__class__</span></code></a> attribute.</p>
<p>An object <em>cls</em> can override if it is considered a class, and what its base
classes are, by having a <a class="reference internal" href="../reference/datamodel.html#type.__bases__" title="type.__bases__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__bases__</span></code></a> attribute (which must be a tuple
of base classes).</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_Hash">
<a class="reference internal" href="hash.html#c.Py_hash_t" title="Py_hash_t"><span class="n"><span class="pre">Py_hash_t</span></span></a><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_Hash</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_Hash" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p id="index-6">Compute and return the hash value of an object <em>o</em>.  On failure, return <code class="docutils literal notranslate"><span class="pre">-1</span></code>.
This is the equivalent of the Python expression <code class="docutils literal notranslate"><span class="pre">hash(o)</span></code>.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.2: </span>The return type is now Py_hash_t.  This is a signed integer the same size
as <a class="reference internal" href="intro.html#c.Py_ssize_t" title="Py_ssize_t"><code class="xref c c-type docutils literal notranslate"><span class="pre">Py_ssize_t</span></code></a>.</p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_HashNotImplemented">
<a class="reference internal" href="hash.html#c.Py_hash_t" title="Py_hash_t"><span class="n"><span class="pre">Py_hash_t</span></span></a><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_HashNotImplemented</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_HashNotImplemented" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>Set a <a class="reference internal" href="../library/exceptions.html#TypeError" title="TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a> indicating that <code class="docutils literal notranslate"><span class="pre">type(o)</span></code> is not <a class="reference internal" href="../glossary.html#term-hashable"><span class="xref std std-term">hashable</span></a> and return <code class="docutils literal notranslate"><span class="pre">-1</span></code>.
This function receives special treatment when stored in a <code class="docutils literal notranslate"><span class="pre">tp_hash</span></code> slot,
allowing a type to explicitly indicate to the interpreter that it is not
hashable.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_IsTrue">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_IsTrue</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_IsTrue" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>Returns <code class="docutils literal notranslate"><span class="pre">1</span></code> if the object <em>o</em> is considered to be true, and <code class="docutils literal notranslate"><span class="pre">0</span></code> otherwise.
This is equivalent to the Python expression <code class="docutils literal notranslate"><span class="pre">not</span> <span class="pre">not</span> <span class="pre">o</span></code>.  On failure, return
<code class="docutils literal notranslate"><span class="pre">-1</span></code>.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_Not">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_Not</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_Not" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>Returns <code class="docutils literal notranslate"><span class="pre">0</span></code> if the object <em>o</em> is considered to be true, and <code class="docutils literal notranslate"><span class="pre">1</span></code> otherwise.
This is equivalent to the Python expression <code class="docutils literal notranslate"><span class="pre">not</span> <span class="pre">o</span></code>.  On failure, return
<code class="docutils literal notranslate"><span class="pre">-1</span></code>.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_Type">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_Type</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_Type" title="Link to this definition">¶</a><br /></dt>
<dd><em class="refcount return_new_ref">Return value: New reference.</em><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p id="index-7">When <em>o</em> is non-<code class="docutils literal notranslate"><span class="pre">NULL</span></code>, returns a type object corresponding to the object type
of object <em>o</em>. On failure, raises <a class="reference internal" href="../library/exceptions.html#SystemError" title="SystemError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">SystemError</span></code></a> and returns <code class="docutils literal notranslate"><span class="pre">NULL</span></code>.  This
is equivalent to the Python expression <code class="docutils literal notranslate"><span class="pre">type(o)</span></code>.
This function creates a new <a class="reference internal" href="../glossary.html#term-strong-reference"><span class="xref std std-term">strong reference</span></a> to the return value.
There’s really no reason to use this
function instead of the <a class="reference internal" href="structures.html#c.Py_TYPE" title="Py_TYPE"><code class="xref c c-func docutils literal notranslate"><span class="pre">Py_TYPE()</span></code></a> function, which returns a
pointer of type <span class="c-expr sig sig-inline c"><a class="reference internal" href="type.html#c.PyTypeObject" title="PyTypeObject"><span class="n">PyTypeObject</span></a><span class="p">*</span></span>, except when a new
<span class="xref std std-term">strong reference</span> is needed.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_TypeCheck">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_TypeCheck</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <a class="reference internal" href="type.html#c.PyTypeObject" title="PyTypeObject"><span class="n"><span class="pre">PyTypeObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">type</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_TypeCheck" title="Link to this definition">¶</a><br /></dt>
<dd><p>Return non-zero if the object <em>o</em> is of type <em>type</em> or a subtype of <em>type</em>, and
<code class="docutils literal notranslate"><span class="pre">0</span></code> otherwise.  Both parameters must be non-<code class="docutils literal notranslate"><span class="pre">NULL</span></code>.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_Size">
<a class="reference internal" href="intro.html#c.Py_ssize_t" title="Py_ssize_t"><span class="n"><span class="pre">Py_ssize_t</span></span></a><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_Size</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_Size" title="Link to this definition">¶</a><br /></dt>
<dt class="sig sig-object c" id="c.PyObject_Length">
<a class="reference internal" href="intro.html#c.Py_ssize_t" title="Py_ssize_t"><span class="n"><span class="pre">Py_ssize_t</span></span></a><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_Length</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_Length" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p id="index-8">Return the length of object <em>o</em>.  If the object <em>o</em> provides either the sequence
and mapping protocols, the sequence length is returned.  On error, <code class="docutils literal notranslate"><span class="pre">-1</span></code> is
returned.  This is the equivalent to the Python expression <code class="docutils literal notranslate"><span class="pre">len(o)</span></code>.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_LengthHint">
<a class="reference internal" href="intro.html#c.Py_ssize_t" title="Py_ssize_t"><span class="n"><span class="pre">Py_ssize_t</span></span></a><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_LengthHint</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <a class="reference internal" href="intro.html#c.Py_ssize_t" title="Py_ssize_t"><span class="n"><span class="pre">Py_ssize_t</span></span></a><span class="w"> </span><span class="n"><span class="pre">defaultvalue</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_LengthHint" title="Link to this definition">¶</a><br /></dt>
<dd><p>Return an estimated length for the object <em>o</em>. First try to return its
actual length, then an estimate using <a class="reference internal" href="../reference/datamodel.html#object.__length_hint__" title="object.__length_hint__"><code class="xref py py-meth docutils literal notranslate"><span class="pre">__length_hint__()</span></code></a>, and
finally return the default value. On error return <code class="docutils literal notranslate"><span class="pre">-1</span></code>. This is the
equivalent to the Python expression <code class="docutils literal notranslate"><span class="pre">operator.length_hint(o,</span> <span class="pre">defaultvalue)</span></code>.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.4.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_GetItem">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_GetItem</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">key</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_GetItem" title="Link to this definition">¶</a><br /></dt>
<dd><em class="refcount return_new_ref">Return value: New reference.</em><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>Return element of <em>o</em> corresponding to the object <em>key</em> or <code class="docutils literal notranslate"><span class="pre">NULL</span></code> on failure.
This is the equivalent of the Python expression <code class="docutils literal notranslate"><span class="pre">o[key]</span></code>.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_SetItem">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_SetItem</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">key</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">v</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_SetItem" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>Map the object <em>key</em> to the value <em>v</em>.  Raise an exception and
return <code class="docutils literal notranslate"><span class="pre">-1</span></code> on failure; return <code class="docutils literal notranslate"><span class="pre">0</span></code> on success.  This is the
equivalent of the Python statement <code class="docutils literal notranslate"><span class="pre">o[key]</span> <span class="pre">=</span> <span class="pre">v</span></code>.  This function <em>does
not</em> steal a reference to <em>v</em>.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_DelItem">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_DelItem</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">key</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_DelItem" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>Remove the mapping for the object <em>key</em> from the object <em>o</em>.  Return <code class="docutils literal notranslate"><span class="pre">-1</span></code>
on failure.  This is equivalent to the Python statement <code class="docutils literal notranslate"><span class="pre">del</span> <span class="pre">o[key]</span></code>.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_DelItemString">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_DelItemString</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <span class="k"><span class="pre">const</span></span><span class="w"> </span><span class="kt"><span class="pre">char</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">key</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_DelItemString" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>This is the same as <a class="reference internal" href="#c.PyObject_DelItem" title="PyObject_DelItem"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_DelItem()</span></code></a>, but <em>key</em> is
specified as a <span class="c-expr sig sig-inline c"><span class="k">const</span><span class="w"> </span><span class="kt">char</span><span class="p">*</span></span> UTF-8 encoded bytes string,
rather than a <span class="c-expr sig sig-inline c"><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n">PyObject</span></a><span class="p">*</span></span>.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_Dir">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_Dir</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_Dir" title="Link to this definition">¶</a><br /></dt>
<dd><em class="refcount return_new_ref">Return value: New reference.</em><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>This is equivalent to the Python expression <code class="docutils literal notranslate"><span class="pre">dir(o)</span></code>, returning a (possibly
empty) list of strings appropriate for the object argument, or <code class="docutils literal notranslate"><span class="pre">NULL</span></code> if there
was an error.  If the argument is <code class="docutils literal notranslate"><span class="pre">NULL</span></code>, this is like the Python <code class="docutils literal notranslate"><span class="pre">dir()</span></code>,
returning the names of the current locals; in this case, if no execution frame
is active then <code class="docutils literal notranslate"><span class="pre">NULL</span></code> is returned but <a class="reference internal" href="exceptions.html#c.PyErr_Occurred" title="PyErr_Occurred"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyErr_Occurred()</span></code></a> will return false.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_GetIter">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_GetIter</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_GetIter" title="Link to this definition">¶</a><br /></dt>
<dd><em class="refcount return_new_ref">Return value: New reference.</em><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>This is equivalent to the Python expression <code class="docutils literal notranslate"><span class="pre">iter(o)</span></code>. It returns a new
iterator for the object argument, or the object  itself if the object is already
an iterator.  Raises <a class="reference internal" href="../library/exceptions.html#TypeError" title="TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a> and returns <code class="docutils literal notranslate"><span class="pre">NULL</span></code> if the object cannot be
iterated.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_SelfIter">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_SelfIter</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">obj</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_SelfIter" title="Link to this definition">¶</a><br /></dt>
<dd><em class="refcount return_new_ref">Return value: New reference.</em><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a>.</em><p>This is equivalent to the Python <code class="docutils literal notranslate"><span class="pre">__iter__(self):</span> <span class="pre">return</span> <span class="pre">self</span></code> method.
It is intended for <a class="reference internal" href="../glossary.html#term-iterator"><span class="xref std std-term">iterator</span></a> types, to be used in the <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_iter" title="PyTypeObject.tp_iter"><code class="xref c c-member docutils literal notranslate"><span class="pre">PyTypeObject.tp_iter</span></code></a> slot.</p>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_GetAIter">
<a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_GetAIter</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_GetAIter" title="Link to this definition">¶</a><br /></dt>
<dd><em class="refcount return_new_ref">Return value: New reference.</em><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a> since version 3.10.</em><p>This is the equivalent to the Python expression <code class="docutils literal notranslate"><span class="pre">aiter(o)</span></code>. Takes an
<code class="xref py py-class docutils literal notranslate"><span class="pre">AsyncIterable</span></code> object and returns an <code class="xref py py-class docutils literal notranslate"><span class="pre">AsyncIterator</span></code> for it.
This is typically a new iterator but if the argument is an
<code class="xref py py-class docutils literal notranslate"><span class="pre">AsyncIterator</span></code>, this returns itself. Raises <a class="reference internal" href="../library/exceptions.html#TypeError" title="TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a> and
returns <code class="docutils literal notranslate"><span class="pre">NULL</span></code> if the object cannot be iterated.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.10.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_GetTypeData">
<span class="kt"><span class="pre">void</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_GetTypeData</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span>, <a class="reference internal" href="type.html#c.PyTypeObject" title="PyTypeObject"><span class="n"><span class="pre">PyTypeObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">cls</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_GetTypeData" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a> since version 3.12.</em><p>Get a pointer to subclass-specific data reserved for <em>cls</em>.</p>
<p>The object <em>o</em> must be an instance of <em>cls</em>, and <em>cls</em> must have been
created using negative <a class="reference internal" href="type.html#c.PyType_Spec.basicsize" title="PyType_Spec.basicsize"><code class="xref c c-member docutils literal notranslate"><span class="pre">PyType_Spec.basicsize</span></code></a>.
Python does not check this.</p>
<p>On error, set an exception and return <code class="docutils literal notranslate"><span class="pre">NULL</span></code>.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.12.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyType_GetTypeDataSize">
<a class="reference internal" href="intro.html#c.Py_ssize_t" title="Py_ssize_t"><span class="n"><span class="pre">Py_ssize_t</span></span></a><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyType_GetTypeDataSize</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="type.html#c.PyTypeObject" title="PyTypeObject"><span class="n"><span class="pre">PyTypeObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">cls</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyType_GetTypeDataSize" title="Link to this definition">¶</a><br /></dt>
<dd><em class="stableabi"> Part of the <a class="reference internal" href="stable.html#stable"><span class="std std-ref">Stable ABI</span></a> since version 3.12.</em><p>Return the size of the instance memory space reserved for <em>cls</em>, i.e. the size of the
memory <a class="reference internal" href="#c.PyObject_GetTypeData" title="PyObject_GetTypeData"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_GetTypeData()</span></code></a> returns.</p>
<p>This may be larger than requested using <a class="reference internal" href="type.html#c.PyType_Spec.basicsize" title="PyType_Spec.basicsize"><code class="xref c c-member docutils literal notranslate"><span class="pre">-PyType_Spec.basicsize</span></code></a>;
it is safe to use this larger size (e.g. with <code class="xref c c-func docutils literal notranslate"><span class="pre">memset()</span></code>).</p>
<p>The type <em>cls</em> <strong>must</strong> have been created using
negative <a class="reference internal" href="type.html#c.PyType_Spec.basicsize" title="PyType_Spec.basicsize"><code class="xref c c-member docutils literal notranslate"><span class="pre">PyType_Spec.basicsize</span></code></a>.
Python does not check this.</p>
<p>On error, set an exception and return a negative value.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.12.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_GetItemData">
<span class="kt"><span class="pre">void</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_GetItemData</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">o</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_GetItemData" title="Link to this definition">¶</a><br /></dt>
<dd><p>Get a pointer to per-item data for a class with
<a class="reference internal" href="typeobj.html#c.Py_TPFLAGS_ITEMS_AT_END" title="Py_TPFLAGS_ITEMS_AT_END"><code class="xref c c-macro docutils literal notranslate"><span class="pre">Py_TPFLAGS_ITEMS_AT_END</span></code></a>.</p>
<p>On error, set an exception and return <code class="docutils literal notranslate"><span class="pre">NULL</span></code>.
<a class="reference internal" href="../library/exceptions.html#TypeError" title="TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a> is raised if <em>o</em> does not have
<a class="reference internal" href="typeobj.html#c.Py_TPFLAGS_ITEMS_AT_END" title="Py_TPFLAGS_ITEMS_AT_END"><code class="xref c c-macro docutils literal notranslate"><span class="pre">Py_TPFLAGS_ITEMS_AT_END</span></code></a> set.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.12.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_VisitManagedDict">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_VisitManagedDict</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">obj</span></span>, <a class="reference internal" href="gcsupport.html#c.visitproc" title="visitproc"><span class="n"><span class="pre">visitproc</span></span></a><span class="w"> </span><span class="n"><span class="pre">visit</span></span>, <span class="kt"><span class="pre">void</span></span><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">arg</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_VisitManagedDict" title="Link to this definition">¶</a><br /></dt>
<dd><p>Visit the managed dictionary of <em>obj</em>.</p>
<p>This function must only be called in a traverse function of the type which
has the <a class="reference internal" href="typeobj.html#c.Py_TPFLAGS_MANAGED_DICT" title="Py_TPFLAGS_MANAGED_DICT"><code class="xref c c-macro docutils literal notranslate"><span class="pre">Py_TPFLAGS_MANAGED_DICT</span></code></a> flag set.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.13.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyObject_ClearManagedDict">
<span class="kt"><span class="pre">void</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyObject_ClearManagedDict</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">obj</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyObject_ClearManagedDict" title="Link to this definition">¶</a><br /></dt>
<dd><p>Clear the managed dictionary of <em>obj</em>.</p>
<p>This function must only be called in a clear function of the type which
has the <a class="reference internal" href="typeobj.html#c.Py_TPFLAGS_MANAGED_DICT" title="Py_TPFLAGS_MANAGED_DICT"><code class="xref c c-macro docutils literal notranslate"><span class="pre">Py_TPFLAGS_MANAGED_DICT</span></code></a> flag set.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.13.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyUnstable_Object_EnableDeferredRefcount">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyUnstable_Object_EnableDeferredRefcount</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">obj</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyUnstable_Object_EnableDeferredRefcount" title="Link to this definition">¶</a><br /></dt>
<dd><div class="unstable-c-api warning admonition">
<em>This is <a class="reference internal" href="stable.html#unstable-c-api"><span class="std std-ref">Unstable API</span></a>. It may change without warning in minor releases.</em></div>
<p>Enable <a class="reference external" href="https://peps.python.org/pep-0703/#deferred-reference-counting">deferred reference counting</a> on <em>obj</em>,
if supported by the runtime.  In the <a class="reference internal" href="../glossary.html#term-free-threading"><span class="xref std std-term">free-threaded</span></a> build,
this allows the interpreter to avoid reference count adjustments to <em>obj</em>,
which may improve multi-threaded performance.  The tradeoff is
that <em>obj</em> will only be deallocated by the tracing garbage collector, and
not when the interpreter no longer has any references to it.</p>
<p>This function returns <code class="docutils literal notranslate"><span class="pre">1</span></code> if deferred reference counting is enabled on <em>obj</em>,
and <code class="docutils literal notranslate"><span class="pre">0</span></code> if deferred reference counting is not supported or if the hint was
ignored by the interpreter, such as when deferred reference counting is already
enabled on <em>obj</em>. This function is thread-safe, and cannot fail.</p>
<p>This function does nothing on builds with the <a class="reference internal" href="../glossary.html#term-GIL"><span class="xref std std-term">GIL</span></a> enabled, which do
not support deferred reference counting. This also does nothing if <em>obj</em> is not
an object tracked by the garbage collector (see <a class="reference internal" href="../library/gc.html#gc.is_tracked" title="gc.is_tracked"><code class="xref py py-func docutils literal notranslate"><span class="pre">gc.is_tracked()</span></code></a> and
<a class="reference internal" href="gcsupport.html#c.PyObject_GC_IsTracked" title="PyObject_GC_IsTracked"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyObject_GC_IsTracked()</span></code></a>).</p>
<p>This function is intended to be used soon after <em>obj</em> is created,
by the code that creates it, such as in the object’s <a class="reference internal" href="typeobj.html#c.PyTypeObject.tp_new" title="PyTypeObject.tp_new"><code class="xref c c-member docutils literal notranslate"><span class="pre">tp_new</span></code></a>
slot.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.14.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyUnstable_Object_IsUniqueReferencedTemporary">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyUnstable_Object_IsUniqueReferencedTemporary</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">obj</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyUnstable_Object_IsUniqueReferencedTemporary" title="Link to this definition">¶</a><br /></dt>
<dd><div class="unstable-c-api warning admonition">
<em>This is <a class="reference internal" href="stable.html#unstable-c-api"><span class="std std-ref">Unstable API</span></a>. It may change without warning in minor releases.</em></div>
<p>Check if <em>obj</em> is a unique temporary object.
Returns <code class="docutils literal notranslate"><span class="pre">1</span></code> if <em>obj</em> is known to be a unique temporary object,
and <code class="docutils literal notranslate"><span class="pre">0</span></code> otherwise.  This function cannot fail, but the check is
conservative, and may return <code class="docutils literal notranslate"><span class="pre">0</span></code> in some cases even if <em>obj</em> is a unique
temporary object.</p>
<p>If an object is a unique temporary, it is guaranteed that the current code
has the only reference to the object. For arguments to C functions, this
should be used instead of checking if the reference count is <code class="docutils literal notranslate"><span class="pre">1</span></code>. Starting
with Python 3.14, the interpreter internally avoids some reference count
modifications when loading objects onto the operands stack by
<a class="reference internal" href="../glossary.html#term-borrowed-reference"><span class="xref std std-term">borrowing</span></a> references when possible, which means
that a reference count of <code class="docutils literal notranslate"><span class="pre">1</span></code> by itself does not guarantee that a function
argument uniquely referenced.</p>
<p>In the example below, <code class="docutils literal notranslate"><span class="pre">my_func</span></code> is called with a unique temporary object
as its argument:</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="n">my_func</span><span class="p">([</span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="mi">2</span><span class="p">,</span><span class="w"> </span><span class="mi">3</span><span class="p">])</span>
</pre></div>
</div>
<p>In the example below, <code class="docutils literal notranslate"><span class="pre">my_func</span></code> is <strong>not</strong> called with a unique temporary
object as its argument, even if its refcount is <code class="docutils literal notranslate"><span class="pre">1</span></code>:</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="n">my_list</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">[</span><span class="mi">1</span><span class="p">,</span><span class="w"> </span><span class="mi">2</span><span class="p">,</span><span class="w"> </span><span class="mi">3</span><span class="p">]</span>
<span class="n">my_func</span><span class="p">(</span><span class="n">my_list</span><span class="p">)</span>
</pre></div>
</div>
<p>See also the function <a class="reference internal" href="refcounting.html#c.Py_REFCNT" title="Py_REFCNT"><code class="xref c c-func docutils literal notranslate"><span class="pre">Py_REFCNT()</span></code></a>.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.14.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyUnstable_IsImmortal">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyUnstable_IsImmortal</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">obj</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyUnstable_IsImmortal" title="Link to this definition">¶</a><br /></dt>
<dd><div class="unstable-c-api warning admonition">
<em>This is <a class="reference internal" href="stable.html#unstable-c-api"><span class="std std-ref">Unstable API</span></a>. It may change without warning in minor releases.</em></div>
<p>This function returns non-zero if <em>obj</em> is <a class="reference internal" href="../glossary.html#term-immortal"><span class="xref std std-term">immortal</span></a>, and zero
otherwise. This function cannot fail.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>Objects that are immortal in one CPython version are not guaranteed to
be immortal in another.</p>
</div>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.14.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyUnstable_TryIncRef">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyUnstable_TryIncRef</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">obj</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyUnstable_TryIncRef" title="Link to this definition">¶</a><br /></dt>
<dd><div class="unstable-c-api warning admonition">
<em>This is <a class="reference internal" href="stable.html#unstable-c-api"><span class="std std-ref">Unstable API</span></a>. It may change without warning in minor releases.</em></div>
<p>Increments the reference count of <em>obj</em> if it is not zero.  Returns <code class="docutils literal notranslate"><span class="pre">1</span></code>
if the object’s reference count was successfully incremented. Otherwise,
this function returns <code class="docutils literal notranslate"><span class="pre">0</span></code>.</p>
<p><a class="reference internal" href="#c.PyUnstable_EnableTryIncRef" title="PyUnstable_EnableTryIncRef"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyUnstable_EnableTryIncRef()</span></code></a> must have been called
earlier on <em>obj</em> or this function may spuriously return <code class="docutils literal notranslate"><span class="pre">0</span></code> in the
<a class="reference internal" href="../glossary.html#term-free-threaded-build"><span class="xref std std-term">free-threaded build</span></a>.</p>
<p>This function is logically equivalent to the following C code, except that
it behaves atomically in the <a class="reference internal" href="../glossary.html#term-free-threaded-build"><span class="xref std std-term">free-threaded build</span></a>:</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">Py_REFCNT</span><span class="p">(</span><span class="n">op</span><span class="p">)</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="mi">0</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w">   </span><span class="n">Py_INCREF</span><span class="p">(</span><span class="n">op</span><span class="p">);</span>
<span class="w">   </span><span class="k">return</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">return</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
</pre></div>
</div>
<p>This is intended as a building block for managing weak references
without the overhead of a Python <a class="reference internal" href="weakref.html#weakrefobjects"><span class="std std-ref">weak reference object</span></a>.</p>
<p>Typically, correct use of this function requires support from <em>obj</em>’s
deallocator (<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>).
For example, the following sketch could be adapted to implement a
“weakmap” that works like a <a class="reference internal" href="../library/weakref.html#weakref.WeakValueDictionary" title="weakref.WeakValueDictionary"><code class="xref py py-class docutils literal notranslate"><span class="pre">WeakValueDictionary</span></code></a>
for a specific type:</p>
<div class="highlight-c notranslate"><div class="highlight"><pre><span></span><span class="n">PyMutex</span><span class="w"> </span><span class="n">mutex</span><span class="p">;</span>

<span class="n">PyObject</span><span class="w"> </span><span class="o">*</span>
<span class="nf">add_entry</span><span class="p">(</span><span class="n">weakmap_key_type</span><span class="w"> </span><span class="o">*</span><span class="n">key</span><span class="p">,</span><span class="w"> </span><span class="n">PyObject</span><span class="w"> </span><span class="o">*</span><span class="n">value</span><span class="p">)</span>
<span class="p">{</span>
<span class="w">    </span><span class="n">PyUnstable_EnableTryIncRef</span><span class="p">(</span><span class="n">value</span><span class="p">);</span>
<span class="w">    </span><span class="n">weakmap_type</span><span class="w"> </span><span class="n">weakmap</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">...;</span>
<span class="w">    </span><span class="n">PyMutex_Lock</span><span class="p">(</span><span class="o">&amp;</span><span class="n">mutex</span><span class="p">);</span>
<span class="w">    </span><span class="n">weakmap_add_entry</span><span class="p">(</span><span class="n">weakmap</span><span class="p">,</span><span class="w"> </span><span class="n">key</span><span class="p">,</span><span class="w"> </span><span class="n">value</span><span class="p">);</span>
<span class="w">    </span><span class="n">PyMutex_Unlock</span><span class="p">(</span><span class="o">&amp;</span><span class="n">mutex</span><span class="p">);</span>
<span class="w">    </span><span class="n">Py_RETURN_NONE</span><span class="p">;</span>
<span class="p">}</span>

<span class="n">PyObject</span><span class="w"> </span><span class="o">*</span>
<span class="nf">get_value</span><span class="p">(</span><span class="n">weakmap_key_type</span><span class="w"> </span><span class="o">*</span><span class="n">key</span><span class="p">)</span>
<span class="p">{</span>
<span class="w">    </span><span class="n">weakmap_type</span><span class="w"> </span><span class="n">weakmap</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">...;</span>
<span class="w">    </span><span class="n">PyMutex_Lock</span><span class="p">(</span><span class="o">&amp;</span><span class="n">mutex</span><span class="p">);</span>
<span class="w">    </span><span class="n">PyObject</span><span class="w"> </span><span class="o">*</span><span class="n">result</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">weakmap_find</span><span class="p">(</span><span class="n">weakmap</span><span class="p">,</span><span class="w"> </span><span class="n">key</span><span class="p">);</span>
<span class="w">    </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">PyUnstable_TryIncRef</span><span class="p">(</span><span class="n">result</span><span class="p">))</span><span class="w"> </span><span class="p">{</span>
<span class="w">        </span><span class="c1">// `result` is safe to use</span>
<span class="w">        </span><span class="n">PyMutex_Unlock</span><span class="p">(</span><span class="o">&amp;</span><span class="n">mutex</span><span class="p">);</span>
<span class="w">        </span><span class="k">return</span><span class="w"> </span><span class="n">result</span><span class="p">;</span>
<span class="w">    </span><span class="p">}</span>
<span class="w">    </span><span class="c1">// if we get here, `result` is starting to be garbage-collected,</span>
<span class="w">    </span><span class="c1">// but has not been removed from the weakmap yet</span>
<span class="w">    </span><span class="n">PyMutex_Unlock</span><span class="p">(</span><span class="o">&amp;</span><span class="n">mutex</span><span class="p">);</span>
<span class="w">    </span><span class="k">return</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<span class="p">}</span>

<span class="c1">// tp_dealloc function for weakmap values</span>
<span class="kt">void</span>
<span class="nf">value_dealloc</span><span class="p">(</span><span class="n">PyObject</span><span class="w"> </span><span class="o">*</span><span class="n">value</span><span class="p">)</span>
<span class="p">{</span>
<span class="w">    </span><span class="n">weakmap_type</span><span class="w"> </span><span class="n">weakmap</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">...;</span>
<span class="w">    </span><span class="n">PyMutex_Lock</span><span class="p">(</span><span class="o">&amp;</span><span class="n">mutex</span><span class="p">);</span>
<span class="w">    </span><span class="n">weakmap_remove_value</span><span class="p">(</span><span class="n">weakmap</span><span class="p">,</span><span class="w"> </span><span class="n">value</span><span class="p">);</span>

<span class="w">    </span><span class="p">...</span>
<span class="w">    </span><span class="n">PyMutex_Unlock</span><span class="p">(</span><span class="o">&amp;</span><span class="n">mutex</span><span class="p">);</span>
<span class="p">}</span>
</pre></div>
</div>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.14.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyUnstable_EnableTryIncRef">
<span class="kt"><span class="pre">void</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyUnstable_EnableTryIncRef</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">obj</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyUnstable_EnableTryIncRef" title="Link to this definition">¶</a><br /></dt>
<dd><div class="unstable-c-api warning admonition">
<em>This is <a class="reference internal" href="stable.html#unstable-c-api"><span class="std std-ref">Unstable API</span></a>. It may change without warning in minor releases.</em></div>
<p>Enables subsequent uses of <a class="reference internal" href="#c.PyUnstable_TryIncRef" title="PyUnstable_TryIncRef"><code class="xref c c-func docutils literal notranslate"><span class="pre">PyUnstable_TryIncRef()</span></code></a> on <em>obj</em>.  The
caller must hold a <a class="reference internal" href="../glossary.html#term-strong-reference"><span class="xref std std-term">strong reference</span></a> to <em>obj</em> when calling this.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.14.</span></p>
</div>
</dd></dl>

<dl class="c function">
<dt class="sig sig-object c" id="c.PyUnstable_Object_IsUniquelyReferenced">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PyUnstable_Object_IsUniquelyReferenced</span></span></span><span class="sig-paren">(</span><a class="reference internal" href="structures.html#c.PyObject" title="PyObject"><span class="n"><span class="pre">PyObject</span></span></a><span class="w"> </span><span class="p"><span class="pre">*</span></span><span class="n"><span class="pre">op</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PyUnstable_Object_IsUniquelyReferenced" title="Link to this definition">¶</a><br /></dt>
<dd><div class="unstable-c-api warning admonition">
<em>This is <a class="reference internal" href="stable.html#unstable-c-api"><span class="std std-ref">Unstable API</span></a>. It may change without warning in minor releases.</em></div>
<p>Determine if <em>op</em> only has one reference.</p>
<p>On GIL-enabled builds, this function is equivalent to
<span class="c-expr sig sig-inline c"><a class="reference internal" href="refcounting.html#c.Py_REFCNT" title="Py_REFCNT"><span class="n">Py_REFCNT</span></a><span class="p">(</span><a class="reference internal" href="#c.PyUnstable_Object_IsUniquelyReferenced" title="op"><span class="n">op</span></a><span class="p">)</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="m">1</span></span>.</p>
<p>On a <a class="reference internal" href="../glossary.html#term-free-threaded-build"><span class="xref std std-term">free-threaded build</span></a>, this checks if <em>op</em>’s
<a class="reference internal" href="../glossary.html#term-reference-count"><span class="xref std std-term">reference count</span></a> is equal to one and additionally checks if <em>op</em>
is only used by this thread. <span class="c-expr sig sig-inline c"><a class="reference internal" href="refcounting.html#c.Py_REFCNT" title="Py_REFCNT"><span class="n">Py_REFCNT</span></a><span class="p">(</span><a class="reference internal" href="#c.PyUnstable_Object_IsUniquelyReferenced" title="op"><span class="n">op</span></a><span class="p">)</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="m">1</span></span> is <strong>not</strong>
thread-safe on free-threaded builds; prefer this function.</p>
<p>The caller must hold an <a class="reference internal" href="../glossary.html#term-attached-thread-state"><span class="xref std std-term">attached thread state</span></a>, despite the fact
that this function doesn’t call into the Python interpreter. This function
cannot fail.</p>
<div class="versionadded">
<p><span class="versionmodified added">Added in version 3.14.</span></p>
</div>
</dd></dl>

</section>


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