496 lines
49 KiB
HTML

<!DOCTYPE html>
<html lang="en" data-content_root="../">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" /><meta name="viewport" content="width=device-width, initial-scale=1" />
<meta property="og:title" content="Sequence Protocol" />
<meta property="og:type" content="website" />
<meta property="og:url" content="https://docs.python.org/3/c-api/sequence.html" />
<meta property="og:site_name" content="Python documentation" />
<meta property="og:image" content="https://docs.python.org/3/_static/og-image.png" />
<meta property="og:image:alt" content="Python documentation" />
<meta property="og:image:width" content="200">
<meta property="og:image:height" content="200">
<meta name="theme-color" content="#3776ab">
<title>Sequence Protocol &#8212; Python 3.13.3 documentation</title><meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="stylesheet" type="text/css" href="../_static/pygments.css?v=b86133f3" />
<link rel="stylesheet" type="text/css" href="../_static/pydoctheme.css?v=23252803" />
<link id="pygments_dark_css" media="(prefers-color-scheme: dark)" rel="stylesheet" type="text/css" href="../_static/pygments_dark.css?v=5349f25f" />
<script src="../_static/documentation_options.js?v=5d57ca2d"></script>
<script src="../_static/doctools.js?v=9bcbadda"></script>
<script src="../_static/sphinx_highlight.js?v=dc90522c"></script>
<script src="../_static/sidebar.js"></script>
<link rel="search" type="application/opensearchdescription+xml"
title="Search within Python 3.13.3 documentation"
href="../_static/opensearch.xml"/>
<link rel="author" title="About these documents" href="../about.html" />
<link rel="index" title="Index" href="../genindex.html" />
<link rel="search" title="Search" href="../search.html" />
<link rel="copyright" title="Copyright" href="../copyright.html" />
<link rel="next" title="Mapping Protocol" href="mapping.html" />
<link rel="prev" title="Number Protocol" href="number.html" />
<link rel="canonical" href="https://docs.python.org/3/c-api/sequence.html">
<style>
@media only screen {
table.full-width-table {
width: 100%;
}
}
</style>
<link rel="stylesheet" href="../_static/pydoctheme_dark.css" media="(prefers-color-scheme: dark)" id="pydoctheme_dark_css">
<link rel="shortcut icon" type="image/png" href="../_static/py.svg" />
<script type="text/javascript" src="../_static/copybutton.js"></script>
<script type="text/javascript" src="../_static/menu.js"></script>
<script type="text/javascript" src="../_static/search-focus.js"></script>
<script type="text/javascript" src="../_static/themetoggle.js"></script>
<script type="text/javascript" src="../_static/rtd_switcher.js"></script>
<meta name="readthedocs-addons-api-version" content="1">
</head>
<body>
<div class="mobile-nav">
<input type="checkbox" id="menuToggler" class="toggler__input" aria-controls="navigation"
aria-pressed="false" aria-expanded="false" role="button" aria-label="Menu" />
<nav class="nav-content" role="navigation">
<label for="menuToggler" class="toggler__label">
<span></span>
</label>
<span class="nav-items-wrapper">
<a href="https://www.python.org/" class="nav-logo">
<img src="../_static/py.svg" alt="Python logo"/>
</a>
<span class="version_switcher_placeholder"></span>
<form role="search" class="search" action="../search.html" method="get">
<svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" class="search-icon">
<path fill-rule="nonzero" fill="currentColor" d="M15.5 14h-.79l-.28-.27a6.5 6.5 0 001.48-5.34c-.47-2.78-2.79-5-5.59-5.34a6.505 6.505 0 00-7.27 7.27c.34 2.8 2.56 5.12 5.34 5.59a6.5 6.5 0 005.34-1.48l.27.28v.79l4.25 4.25c.41.41 1.08.41 1.49 0 .41-.41.41-1.08 0-1.49L15.5 14zm-6 0C7.01 14 5 11.99 5 9.5S7.01 5 9.5 5 14 7.01 14 9.5 11.99 14 9.5 14z"></path>
</svg>
<input placeholder="Quick search" aria-label="Quick search" type="search" name="q" />
<input type="submit" value="Go"/>
</form>
</span>
</nav>
<div class="menu-wrapper">
<nav class="menu" role="navigation" aria-label="main navigation">
<div class="language_switcher_placeholder"></div>
<label class="theme-selector-label">
Theme
<select class="theme-selector" oninput="activateTheme(this.value)">
<option value="auto" selected>Auto</option>
<option value="light">Light</option>
<option value="dark">Dark</option>
</select>
</label>
<div>
<h4>Previous topic</h4>
<p class="topless"><a href="number.html"
title="previous chapter">Number Protocol</a></p>
</div>
<div>
<h4>Next topic</h4>
<p class="topless"><a href="mapping.html"
title="next chapter">Mapping Protocol</a></p>
</div>
<div role="note" aria-label="source link">
<h3>This Page</h3>
<ul class="this-page-menu">
<li><a href="../bugs.html">Report a Bug</a></li>
<li>
<a href="https://github.com/python/cpython/blob/main/Doc/c-api/sequence.rst"
rel="nofollow">Show Source
</a>
</li>
</ul>
</div>
</nav>
</div>
</div>
<div class="related" role="navigation" aria-label="Related">
<h3>Navigation</h3>
<ul>
<li class="right" style="margin-right: 10px">
<a href="../genindex.html" title="General Index"
accesskey="I">index</a></li>
<li class="right" >
<a href="../py-modindex.html" title="Python Module Index"
>modules</a> |</li>
<li class="right" >
<a href="mapping.html" title="Mapping Protocol"
accesskey="N">next</a> |</li>
<li class="right" >
<a href="number.html" title="Number Protocol"
accesskey="P">previous</a> |</li>
<li><img src="../_static/py.svg" alt="Python logo" style="vertical-align: middle; margin-top: -1px"/></li>
<li><a href="https://www.python.org/">Python</a> &#187;</li>
<li class="switchers">
<div class="language_switcher_placeholder"></div>
<div class="version_switcher_placeholder"></div>
</li>
<li>
</li>
<li id="cpython-language-and-version">
<a href="../index.html">3.13.3 Documentation</a> &#187;
</li>
<li class="nav-item nav-item-1"><a href="index.html" >Python/C API Reference Manual</a> &#187;</li>
<li class="nav-item nav-item-2"><a href="abstract.html" accesskey="U">Abstract Objects Layer</a> &#187;</li>
<li class="nav-item nav-item-this"><a href="">Sequence Protocol</a></li>
<li class="right">
<div class="inline-search" role="search">
<form class="inline-search" action="../search.html" method="get">
<input placeholder="Quick search" aria-label="Quick search" type="search" name="q" id="search-box" />
<input type="submit" value="Go" />
</form>
</div>
|
</li>
<li class="right">
<label class="theme-selector-label">
Theme
<select class="theme-selector" oninput="activateTheme(this.value)">
<option value="auto" selected>Auto</option>
<option value="light">Light</option>
<option value="dark">Dark</option>
</select>
</label> |</li>
</ul>
</div>
<div class="document">
<div class="documentwrapper">
<div class="bodywrapper">
<div class="body" role="main">
<section id="sequence-protocol">
<span id="sequence"></span><h1>Sequence Protocol<a class="headerlink" href="#sequence-protocol" title="Link to this heading"></a></h1>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_Check">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PySequence_Check</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.PySequence_Check" 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 object provides the sequence protocol, and <code class="docutils literal notranslate"><span class="pre">0</span></code> otherwise.
Note that it returns <code class="docutils literal notranslate"><span class="pre">1</span></code> for Python classes with a <a class="reference internal" href="../reference/datamodel.html#object.__getitem__" title="object.__getitem__"><code class="xref py py-meth docutils literal notranslate"><span class="pre">__getitem__()</span></code></a>
method, unless they are <a class="reference internal" href="../library/stdtypes.html#dict" title="dict"><code class="xref py py-class docutils literal notranslate"><span class="pre">dict</span></code></a> subclasses, since in general it
is impossible to determine what type of keys the class supports. This
function always succeeds.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_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">PySequence_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.PySequence_Size" title="Link to this definition"></a><br /></dt>
<dt class="sig sig-object c" id="c.PySequence_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">PySequence_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.PySequence_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-0">Returns the number of objects in sequence <em>o</em> on success, and <code class="docutils literal notranslate"><span class="pre">-1</span></code> on
failure. This is 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.PySequence_Concat">
<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">PySequence_Concat</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="sig-paren">)</span><a class="headerlink" href="#c.PySequence_Concat" 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 the concatenation of <em>o1</em> and <em>o2</em> on success, and <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">o1</span> <span class="pre">+</span> <span class="pre">o2</span></code>.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_Repeat">
<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">PySequence_Repeat</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">count</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PySequence_Repeat" 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 the result of repeating sequence object <em>o</em> <em>count</em> times, 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</span> <span class="pre">*</span> <span class="pre">count</span></code>.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_InPlaceConcat">
<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">PySequence_InPlaceConcat</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="sig-paren">)</span><a class="headerlink" href="#c.PySequence_InPlaceConcat" 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 the concatenation of <em>o1</em> and <em>o2</em> on success, and <code class="docutils literal notranslate"><span class="pre">NULL</span></code> on failure.
The operation is done <em>in-place</em> when <em>o1</em> supports it. This is the equivalent
of the Python expression <code class="docutils literal notranslate"><span class="pre">o1</span> <span class="pre">+=</span> <span class="pre">o2</span></code>.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_InPlaceRepeat">
<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">PySequence_InPlaceRepeat</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">count</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PySequence_InPlaceRepeat" 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 the result of repeating sequence object <em>o</em> <em>count</em> times, or <code class="docutils literal notranslate"><span class="pre">NULL</span></code> on
failure. The operation is done <em>in-place</em> when <em>o</em> supports it. This is the
equivalent of the Python expression <code class="docutils literal notranslate"><span class="pre">o</span> <span class="pre">*=</span> <span class="pre">count</span></code>.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_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">PySequence_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="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">i</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PySequence_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 the <em>i</em>th element of <em>o</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[i]</span></code>.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_GetSlice">
<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">PySequence_GetSlice</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">i1</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">i2</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PySequence_GetSlice" 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 the slice of sequence object <em>o</em> between <em>i1</em> and <em>i2</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[i1:i2]</span></code>.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_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">PySequence_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="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">i</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.PySequence_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>Assign object <em>v</em> to the <em>i</em>th element of <em>o</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[i]</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>
<p>If <em>v</em> is <code class="docutils literal notranslate"><span class="pre">NULL</span></code>, the element is deleted, but this feature is
deprecated in favour of using <a class="reference internal" href="#c.PySequence_DelItem" title="PySequence_DelItem"><code class="xref c c-func docutils literal notranslate"><span class="pre">PySequence_DelItem()</span></code></a>.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_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">PySequence_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="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">i</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PySequence_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>Delete the <em>i</em>th element of 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[i]</span></code>.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_SetSlice">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PySequence_SetSlice</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">i1</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">i2</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.PySequence_SetSlice" 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>Assign the sequence object <em>v</em> to the slice in sequence object <em>o</em> from <em>i1</em> to
<em>i2</em>. This is the equivalent of the Python statement <code class="docutils literal notranslate"><span class="pre">o[i1:i2]</span> <span class="pre">=</span> <span class="pre">v</span></code>.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_DelSlice">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PySequence_DelSlice</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">i1</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">i2</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PySequence_DelSlice" 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>Delete the slice in sequence object <em>o</em> from <em>i1</em> to <em>i2</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[i1:i2]</span></code>.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_Count">
<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">PySequence_Count</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="sig-paren">)</span><a class="headerlink" href="#c.PySequence_Count" 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 the number of occurrences of <em>value</em> in <em>o</em>, that is, return the number
of keys for which <code class="docutils literal notranslate"><span class="pre">o[key]</span> <span class="pre">==</span> <span class="pre">value</span></code>. On failure, return <code class="docutils literal notranslate"><span class="pre">-1</span></code>. This is
equivalent to the Python expression <code class="docutils literal notranslate"><span class="pre">o.count(value)</span></code>.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_Contains">
<span class="kt"><span class="pre">int</span></span><span class="w"> </span><span class="sig-name descname"><span class="n"><span class="pre">PySequence_Contains</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="sig-paren">)</span><a class="headerlink" href="#c.PySequence_Contains" 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>Determine if <em>o</em> contains <em>value</em>. If an item in <em>o</em> is equal to <em>value</em>,
return <code class="docutils literal notranslate"><span class="pre">1</span></code>, otherwise return <code class="docutils literal notranslate"><span class="pre">0</span></code>. On error, return <code class="docutils literal notranslate"><span class="pre">-1</span></code>. This is
equivalent to the Python expression <code class="docutils literal notranslate"><span class="pre">value</span> <span class="pre">in</span> <span class="pre">o</span></code>.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_Index">
<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">PySequence_Index</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="sig-paren">)</span><a class="headerlink" href="#c.PySequence_Index" 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 the first index <em>i</em> for which <code class="docutils literal notranslate"><span class="pre">o[i]</span> <span class="pre">==</span> <span class="pre">value</span></code>. On error, return
<code class="docutils literal notranslate"><span class="pre">-1</span></code>. This is equivalent to the Python expression <code class="docutils literal notranslate"><span class="pre">o.index(value)</span></code>.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_List">
<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">PySequence_List</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.PySequence_List" 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 a list object with the same contents as the sequence or iterable <em>o</em>,
or <code class="docutils literal notranslate"><span class="pre">NULL</span></code> on failure. The returned list is guaranteed to be new. This is
equivalent to the Python expression <code class="docutils literal notranslate"><span class="pre">list(o)</span></code>.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_Tuple">
<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">PySequence_Tuple</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.PySequence_Tuple" 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">Return a tuple object with the same contents as the sequence or iterable <em>o</em>,
or <code class="docutils literal notranslate"><span class="pre">NULL</span></code> on failure. If <em>o</em> is a tuple, a new reference will be returned,
otherwise a tuple will be constructed with the appropriate contents. This is
equivalent to the Python expression <code class="docutils literal notranslate"><span class="pre">tuple(o)</span></code>.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_Fast">
<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">PySequence_Fast</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">m</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PySequence_Fast" 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 the sequence or iterable <em>o</em> as an object usable by the other
<code class="docutils literal notranslate"><span class="pre">PySequence_Fast*</span></code> family of functions. If the object is not a sequence or
iterable, 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> with <em>m</em> as the message text. Returns
<code class="docutils literal notranslate"><span class="pre">NULL</span></code> on failure.</p>
<p>The <code class="docutils literal notranslate"><span class="pre">PySequence_Fast*</span></code> functions are thus named because they assume
<em>o</em> is a <a class="reference internal" href="tuple.html#c.PyTupleObject" title="PyTupleObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyTupleObject</span></code></a> or a <a class="reference internal" href="list.html#c.PyListObject" title="PyListObject"><code class="xref c c-type docutils literal notranslate"><span class="pre">PyListObject</span></code></a> and access
the data fields of <em>o</em> directly.</p>
<p>As a CPython implementation detail, if <em>o</em> is already a sequence or list, it
will be returned.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_Fast_GET_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">PySequence_Fast_GET_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.PySequence_Fast_GET_SIZE" title="Link to this definition"></a><br /></dt>
<dd><p>Returns the length of <em>o</em>, assuming that <em>o</em> was returned by
<a class="reference internal" href="#c.PySequence_Fast" title="PySequence_Fast"><code class="xref c c-func docutils literal notranslate"><span class="pre">PySequence_Fast()</span></code></a> and that <em>o</em> is not <code class="docutils literal notranslate"><span class="pre">NULL</span></code>. The size can also be
retrieved by calling <a class="reference internal" href="#c.PySequence_Size" title="PySequence_Size"><code class="xref c c-func docutils literal notranslate"><span class="pre">PySequence_Size()</span></code></a> on <em>o</em>, but
<a class="reference internal" href="#c.PySequence_Fast_GET_SIZE" title="PySequence_Fast_GET_SIZE"><code class="xref c c-func docutils literal notranslate"><span class="pre">PySequence_Fast_GET_SIZE()</span></code></a> is faster because it can assume <em>o</em> is a
list or tuple.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_Fast_GET_ITEM">
<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">PySequence_Fast_GET_ITEM</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">i</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PySequence_Fast_GET_ITEM" title="Link to this definition"></a><br /></dt>
<dd><em class="refcount return_borrowed_ref">Return value: Borrowed reference.</em><p>Return the <em>i</em>th element of <em>o</em>, assuming that <em>o</em> was returned by
<a class="reference internal" href="#c.PySequence_Fast" title="PySequence_Fast"><code class="xref c c-func docutils literal notranslate"><span class="pre">PySequence_Fast()</span></code></a>, <em>o</em> is not <code class="docutils literal notranslate"><span class="pre">NULL</span></code>, and that <em>i</em> is within bounds.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_Fast_ITEMS">
<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">PySequence_Fast_ITEMS</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.PySequence_Fast_ITEMS" title="Link to this definition"></a><br /></dt>
<dd><p>Return the underlying array of PyObject pointers. Assumes that <em>o</em> was returned
by <a class="reference internal" href="#c.PySequence_Fast" title="PySequence_Fast"><code class="xref c c-func docutils literal notranslate"><span class="pre">PySequence_Fast()</span></code></a> and <em>o</em> is not <code class="docutils literal notranslate"><span class="pre">NULL</span></code>.</p>
<p>Note, if a list gets resized, the reallocation may relocate the items array.
So, only use the underlying array pointer in contexts where the sequence
cannot change.</p>
</dd></dl>
<dl class="c function">
<dt class="sig sig-object c" id="c.PySequence_ITEM">
<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">PySequence_ITEM</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">i</span></span><span class="sig-paren">)</span><a class="headerlink" href="#c.PySequence_ITEM" title="Link to this definition"></a><br /></dt>
<dd><em class="refcount return_new_ref">Return value: New reference.</em><p>Return the <em>i</em>th element of <em>o</em> or <code class="docutils literal notranslate"><span class="pre">NULL</span></code> on failure. Faster form of
<a class="reference internal" href="#c.PySequence_GetItem" title="PySequence_GetItem"><code class="xref c c-func docutils literal notranslate"><span class="pre">PySequence_GetItem()</span></code></a> but without checking that
<a class="reference internal" href="#c.PySequence_Check" title="PySequence_Check"><code class="xref c c-func docutils literal notranslate"><span class="pre">PySequence_Check()</span></code></a> on <em>o</em> is true and without adjustment for negative
indices.</p>
</dd></dl>
</section>
<div class="clearer"></div>
</div>
</div>
</div>
<div class="sphinxsidebar" role="navigation" aria-label="Main">
<div class="sphinxsidebarwrapper">
<div>
<h4>Previous topic</h4>
<p class="topless"><a href="number.html"
title="previous chapter">Number Protocol</a></p>
</div>
<div>
<h4>Next topic</h4>
<p class="topless"><a href="mapping.html"
title="next chapter">Mapping Protocol</a></p>
</div>
<div role="note" aria-label="source link">
<h3>This Page</h3>
<ul class="this-page-menu">
<li><a href="../bugs.html">Report a Bug</a></li>
<li>
<a href="https://github.com/python/cpython/blob/main/Doc/c-api/sequence.rst"
rel="nofollow">Show Source
</a>
</li>
</ul>
</div>
</div>
<div id="sidebarbutton" title="Collapse sidebar">
<span>«</span>
</div>
</div>
<div class="clearer"></div>
</div>
<div class="related" role="navigation" aria-label="Related">
<h3>Navigation</h3>
<ul>
<li class="right" style="margin-right: 10px">
<a href="../genindex.html" title="General Index"
>index</a></li>
<li class="right" >
<a href="../py-modindex.html" title="Python Module Index"
>modules</a> |</li>
<li class="right" >
<a href="mapping.html" title="Mapping Protocol"
>next</a> |</li>
<li class="right" >
<a href="number.html" title="Number Protocol"
>previous</a> |</li>
<li><img src="../_static/py.svg" alt="Python logo" style="vertical-align: middle; margin-top: -1px"/></li>
<li><a href="https://www.python.org/">Python</a> &#187;</li>
<li class="switchers">
<div class="language_switcher_placeholder"></div>
<div class="version_switcher_placeholder"></div>
</li>
<li>
</li>
<li id="cpython-language-and-version">
<a href="../index.html">3.13.3 Documentation</a> &#187;
</li>
<li class="nav-item nav-item-1"><a href="index.html" >Python/C API Reference Manual</a> &#187;</li>
<li class="nav-item nav-item-2"><a href="abstract.html" >Abstract Objects Layer</a> &#187;</li>
<li class="nav-item nav-item-this"><a href="">Sequence Protocol</a></li>
<li class="right">
<div class="inline-search" role="search">
<form class="inline-search" action="../search.html" method="get">
<input placeholder="Quick search" aria-label="Quick search" type="search" name="q" id="search-box" />
<input type="submit" value="Go" />
</form>
</div>
|
</li>
<li class="right">
<label class="theme-selector-label">
Theme
<select class="theme-selector" oninput="activateTheme(this.value)">
<option value="auto" selected>Auto</option>
<option value="light">Light</option>
<option value="dark">Dark</option>
</select>
</label> |</li>
</ul>
</div>
<div class="footer">
&copy;
<a href="../copyright.html">
Copyright
</a>
2001-2025, Python Software Foundation.
<br />
This page is licensed under the Python Software Foundation License Version 2.
<br />
Examples, recipes, and other code in the documentation are additionally licensed under the Zero Clause BSD License.
<br />
See <a href="/license.html">History and License</a> for more information.<br />
<br />
The Python Software Foundation is a non-profit corporation.
<a href="https://www.python.org/psf/donations/">Please donate.</a>
<br />
<br />
Last updated on Apr 08, 2025 (14:33 UTC).
<a href="/bugs.html">Found a bug</a>?
<br />
Created using <a href="https://www.sphinx-doc.org/">Sphinx</a> 8.2.3.
</div>
</body>
</html>