Spaces:

parthtamu
/

rag-code-assistant

Sleeping

File size: 27,156 Bytes

dcac338

<!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="Extending" />
<meta property="og:type" content="website" />
<meta property="og:url" content="https://docs.python.org/3/library/asyncio-extending.html" />
<meta property="og:site_name" content="Python documentation" />
<meta property="og:description" content="The main direction for asyncio extending is writing custom event loop classes. Asyncio has helpers that could be used to simplify this task. Writing a Custom Event Loop: asyncio.AbstractEventLoop d..." />
<meta property="og:image:width" content="1146" />
<meta property="og:image:height" content="600" />
<meta property="og:image" content="https://docs.python.org/3.15/_images/social_previews/summary_library_asyncio-extending_1cf80ba1.png" />
<meta property="og:image:alt" content="The main direction for asyncio extending is writing custom event loop classes. Asyncio has helpers that could be used to simplify this task. Writing a Custom Event Loop: asyncio.AbstractEventLoop d..." />
<meta name="description" content="The main direction for asyncio extending is writing custom event loop classes. Asyncio has helpers that could be used to simplify this task. Writing a Custom Event Loop: asyncio.AbstractEventLoop d..." />
<meta name="twitter:card" content="summary_large_image" />
<meta name="theme-color" content="#3776ab">

    <title>Extending &#8212; Python 3.15.0a6 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/classic.css?v=234b1a7c" />
    <link rel="stylesheet" type="text/css" href="../_static/pydoctheme.css?v=89a2f22a" />
    <link rel="stylesheet" type="text/css" href="../_static/profiling-sampling-visualization.css?v=0c2600ae" />
    <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=6b7c9ff5"></script>
    <script src="../_static/doctools.js?v=9bcbadda"></script>
    <script src="../_static/sphinx_highlight.js?v=dc90522c"></script>
    <script src="../_static/profiling-sampling-visualization.js?v=9811ed04"></script>
    
    <script src="../_static/sidebar.js"></script>
    
    <link rel="search" type="application/opensearchdescription+xml"
          title="Search within Python 3.15.0a6 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="High-level API Index" href="asyncio-api-index.html" />
    <link rel="prev" title="Platform Support" href="asyncio-platforms.html" />
    
      
      <script defer file-types="bz2,epub,zip" data-domain="docs.python.org" src="https://analytics.python.org/js/script.file-downloads.outbound-links.js"></script>
      
      <link rel="canonical" href="https://docs.python.org/3/library/asyncio-extending.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>
    <h3><a href="../contents.html">Table of Contents</a></h3>
    <ul>
<li><a class="reference internal" href="#">Extending</a><ul>
<li><a class="reference internal" href="#writing-a-custom-event-loop">Writing a Custom Event Loop</a></li>
<li><a class="reference internal" href="#future-and-task-private-constructors">Future and Task private constructors</a></li>
<li><a class="reference internal" href="#task-lifetime-support">Task lifetime support</a></li>
</ul>
</li>
</ul>

  </div>
  <div>
    <h4>Previous topic</h4>
    <p class="topless"><a href="asyncio-platforms.html"
                          title="previous chapter">Platform Support</a></p>
  </div>
  <div>
    <h4>Next topic</h4>
    <p class="topless"><a href="asyncio-api-index.html"
                          title="next chapter">High-level API Index</a></p>
  </div>
  <script>
    document.addEventListener('DOMContentLoaded', () => {
        const title = document.querySelector('meta[property="og:title"]').content;
        const elements = document.querySelectorAll('.improvepage');
        const pageurl = window.location.href.split('?')[0];
        elements.forEach(element => {
            const url = new URL(element.href.split('?')[0].replace("-nojs", ""));
            url.searchParams.set('pagetitle', title);
            url.searchParams.set('pageurl', pageurl);
            url.searchParams.set('pagesource', "library/asyncio-extending.rst");
            element.href = url.toString();
        });
    });
  </script>
  <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 class="improvepage" href="../improve-page-nojs.html">Improve this page</a></li>
      <li>
        <a href="https://github.com/python/cpython/blob/main/Doc/library/asyncio-extending.rst?plain=1"
            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="asyncio-api-index.html" title="High-level API Index"
             accesskey="N">next</a> |</li>
        <li class="right" >
          <a href="asyncio-platforms.html" title="Platform Support"
             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">3.15.0a6 Documentation</a> &#187;
    </li>

          <li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> &#187;</li>
          <li class="nav-item nav-item-2"><a href="ipc.html" >Networking and Interprocess Communication</a> &#187;</li>
          <li class="nav-item nav-item-3"><a href="asyncio.html" accesskey="U"><code class="xref py py-mod docutils literal notranslate"><span class="pre">asyncio</span></code> — Asynchronous I/O</a> &#187;</li>
        <li class="nav-item nav-item-this"><a href="">Extending</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="extending">
<h1>Extending<a class="headerlink" href="#extending" title="Link to this heading">¶</a></h1>
<p>The main direction for <a class="reference internal" href="asyncio.html#module-asyncio" title="asyncio: Asynchronous I/O."><code class="xref py py-mod docutils literal notranslate"><span class="pre">asyncio</span></code></a> extending is writing custom <em>event loop</em>
classes. Asyncio has helpers that could be used to simplify this task.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>Third-parties should reuse existing asyncio code with caution,
a new Python version is free to break backward compatibility
in <em>internal</em> part of API.</p>
</div>
<section id="writing-a-custom-event-loop">
<h2>Writing a Custom Event Loop<a class="headerlink" href="#writing-a-custom-event-loop" title="Link to this heading">¶</a></h2>
<p><a class="reference internal" href="asyncio-eventloop.html#asyncio.AbstractEventLoop" title="asyncio.AbstractEventLoop"><code class="xref py py-class docutils literal notranslate"><span class="pre">asyncio.AbstractEventLoop</span></code></a> declares very many methods.  Implementing all them
from scratch is a tedious job.</p>
<p>A loop can get many common methods implementation for free by inheriting from
<code class="xref py py-class docutils literal notranslate"><span class="pre">asyncio.BaseEventLoop</span></code>.</p>
<p>In turn, the successor should implement a bunch of <em>private</em> methods declared but not
implemented in <code class="xref py py-class docutils literal notranslate"><span class="pre">asyncio.BaseEventLoop</span></code>.</p>
<p>For example, <code class="docutils literal notranslate"><span class="pre">loop.create_connection()</span></code> checks arguments, resolves DNS addresses, and
calls <code class="docutils literal notranslate"><span class="pre">loop._make_socket_transport()</span></code> that should be implemented by inherited class.
The <code class="docutils literal notranslate"><span class="pre">_make_socket_transport()</span></code> method is not documented and is considered as an
<em>internal</em> API.</p>
</section>
<section id="future-and-task-private-constructors">
<h2>Future and Task private constructors<a class="headerlink" href="#future-and-task-private-constructors" title="Link to this heading">¶</a></h2>
<p><a class="reference internal" href="asyncio-future.html#asyncio.Future" title="asyncio.Future"><code class="xref py py-class docutils literal notranslate"><span class="pre">asyncio.Future</span></code></a> and <a class="reference internal" href="asyncio-task.html#asyncio.Task" title="asyncio.Task"><code class="xref py py-class docutils literal notranslate"><span class="pre">asyncio.Task</span></code></a> should be never created directly,
please use corresponding <a class="reference internal" href="asyncio-eventloop.html#asyncio.loop.create_future" title="asyncio.loop.create_future"><code class="xref py py-meth docutils literal notranslate"><span class="pre">loop.create_future()</span></code></a> and <a class="reference internal" href="asyncio-eventloop.html#asyncio.loop.create_task" title="asyncio.loop.create_task"><code class="xref py py-meth docutils literal notranslate"><span class="pre">loop.create_task()</span></code></a>,
or <a class="reference internal" href="asyncio-task.html#asyncio.create_task" title="asyncio.create_task"><code class="xref py py-func docutils literal notranslate"><span class="pre">asyncio.create_task()</span></code></a> factories instead.</p>
<p>However, third-party <em>event loops</em> may <em>reuse</em> built-in future and task implementations
for the sake of getting a complex and highly optimized code for free.</p>
<p>For this purpose the following, <em>private</em> constructors are listed:</p>
<dl class="py method">
<dt class="sig sig-object py" id="asyncio.Future.__init__">
<span class="sig-prename descclassname"><span class="pre">Future.</span></span><span class="sig-name descname"><span class="pre">__init__</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="keyword-only-separator o"><abbr title="Keyword-only parameters separator (PEP 3102)"><span class="pre">*</span></abbr></span></em>, <em class="sig-param"><span class="n"><span class="pre">loop</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#asyncio.Future.__init__" title="Link to this definition">¶</a></dt>
<dd><p>Create a built-in future instance.</p>
<p><em>loop</em> is an optional event loop instance.</p>
</dd></dl>

<dl class="py method">
<dt class="sig sig-object py" id="asyncio.Task.__init__">
<span class="sig-prename descclassname"><span class="pre">Task.</span></span><span class="sig-name descname"><span class="pre">__init__</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">coro</span></span></em>, <em class="sig-param"><span class="keyword-only-separator o"><abbr title="Keyword-only parameters separator (PEP 3102)"><span class="pre">*</span></abbr></span></em>, <em class="sig-param"><span class="n"><span class="pre">loop</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">name</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">context</span></span><span class="o"><span class="pre">=</span></span><span class="default_value"><span class="pre">None</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#asyncio.Task.__init__" title="Link to this definition">¶</a></dt>
<dd><p>Create a built-in task instance.</p>
<p><em>loop</em> is an optional event loop instance. The rest of arguments are described in
<a class="reference internal" href="asyncio-eventloop.html#asyncio.loop.create_task" title="asyncio.loop.create_task"><code class="xref py py-meth docutils literal notranslate"><span class="pre">loop.create_task()</span></code></a> description.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.11: </span><em>context</em> argument is added.</p>
</div>
</dd></dl>

</section>
<section id="task-lifetime-support">
<h2>Task lifetime support<a class="headerlink" href="#task-lifetime-support" title="Link to this heading">¶</a></h2>
<p>A third party task implementation should call the following functions to keep a task
visible by <a class="reference internal" href="asyncio-task.html#asyncio.all_tasks" title="asyncio.all_tasks"><code class="xref py py-func docutils literal notranslate"><span class="pre">asyncio.all_tasks()</span></code></a> and <a class="reference internal" href="asyncio-task.html#asyncio.current_task" title="asyncio.current_task"><code class="xref py py-func docutils literal notranslate"><span class="pre">asyncio.current_task()</span></code></a>:</p>
<dl class="py function">
<dt class="sig sig-object py" id="asyncio._register_task">
<span class="sig-prename descclassname"><span class="pre">asyncio.</span></span><span class="sig-name descname"><span class="pre">_register_task</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">task</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#asyncio._register_task" title="Link to this definition">¶</a></dt>
<dd><p>Register a new <em>task</em> as managed by <em>asyncio</em>.</p>
<p>Call the function from a task constructor.</p>
</dd></dl>

<dl class="py function">
<dt class="sig sig-object py" id="asyncio._unregister_task">
<span class="sig-prename descclassname"><span class="pre">asyncio.</span></span><span class="sig-name descname"><span class="pre">_unregister_task</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">task</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#asyncio._unregister_task" title="Link to this definition">¶</a></dt>
<dd><p>Unregister a <em>task</em> from <em>asyncio</em> internal structures.</p>
<p>The function should be called when a task is about to finish.</p>
</dd></dl>

<dl class="py function">
<dt class="sig sig-object py" id="asyncio._enter_task">
<span class="sig-prename descclassname"><span class="pre">asyncio.</span></span><span class="sig-name descname"><span class="pre">_enter_task</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">loop</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">task</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#asyncio._enter_task" title="Link to this definition">¶</a></dt>
<dd><p>Switch the current task to the <em>task</em> argument.</p>
<p>Call the function just before executing a portion of embedded <em>coroutine</em>
(<a class="reference internal" href="../reference/datamodel.html#coroutine.send" title="coroutine.send"><code class="xref py py-meth docutils literal notranslate"><span class="pre">coroutine.send()</span></code></a> or <a class="reference internal" href="../reference/datamodel.html#coroutine.throw" title="coroutine.throw"><code class="xref py py-meth docutils literal notranslate"><span class="pre">coroutine.throw()</span></code></a>).</p>
</dd></dl>

<dl class="py function">
<dt class="sig sig-object py" id="asyncio._leave_task">
<span class="sig-prename descclassname"><span class="pre">asyncio.</span></span><span class="sig-name descname"><span class="pre">_leave_task</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">loop</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">task</span></span></em><span class="sig-paren">)</span><a class="headerlink" href="#asyncio._leave_task" title="Link to this definition">¶</a></dt>
<dd><p>Switch the current task back from <em>task</em> to <code class="docutils literal notranslate"><span class="pre">None</span></code>.</p>
<p>Call the function just after <a class="reference internal" href="../reference/datamodel.html#coroutine.send" title="coroutine.send"><code class="xref py py-meth docutils literal notranslate"><span class="pre">coroutine.send()</span></code></a> or <a class="reference internal" href="../reference/datamodel.html#coroutine.throw" title="coroutine.throw"><code class="xref py py-meth docutils literal notranslate"><span class="pre">coroutine.throw()</span></code></a>
execution.</p>
</dd></dl>

</section>
</section>


            <div class="clearer"></div>
          </div>
        </div>
      </div>
      <div class="sphinxsidebar" role="navigation" aria-label="Main">
        <div class="sphinxsidebarwrapper">
  <div>
    <h3><a href="../contents.html">Table of Contents</a></h3>
    <ul>
<li><a class="reference internal" href="#">Extending</a><ul>
<li><a class="reference internal" href="#writing-a-custom-event-loop">Writing a Custom Event Loop</a></li>
<li><a class="reference internal" href="#future-and-task-private-constructors">Future and Task private constructors</a></li>
<li><a class="reference internal" href="#task-lifetime-support">Task lifetime support</a></li>
</ul>
</li>
</ul>

  </div>
  <div>
    <h4>Previous topic</h4>
    <p class="topless"><a href="asyncio-platforms.html"
                          title="previous chapter">Platform Support</a></p>
  </div>
  <div>
    <h4>Next topic</h4>
    <p class="topless"><a href="asyncio-api-index.html"
                          title="next chapter">High-level API Index</a></p>
  </div>
  <script>
    document.addEventListener('DOMContentLoaded', () => {
        const title = document.querySelector('meta[property="og:title"]').content;
        const elements = document.querySelectorAll('.improvepage');
        const pageurl = window.location.href.split('?')[0];
        elements.forEach(element => {
            const url = new URL(element.href.split('?')[0].replace("-nojs", ""));
            url.searchParams.set('pagetitle', title);
            url.searchParams.set('pageurl', pageurl);
            url.searchParams.set('pagesource', "library/asyncio-extending.rst");
            element.href = url.toString();
        });
    });
  </script>
  <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 class="improvepage" href="../improve-page-nojs.html">Improve this page</a></li>
      <li>
        <a href="https://github.com/python/cpython/blob/main/Doc/library/asyncio-extending.rst?plain=1"
            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="asyncio-api-index.html" title="High-level API Index"
             >next</a> |</li>
        <li class="right" >
          <a href="asyncio-platforms.html" title="Platform Support"
             >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">3.15.0a6 Documentation</a> &#187;
    </li>

          <li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> &#187;</li>
          <li class="nav-item nav-item-2"><a href="ipc.html" >Networking and Interprocess Communication</a> &#187;</li>
          <li class="nav-item nav-item-3"><a href="asyncio.html" ><code class="xref py py-mod docutils literal notranslate"><span class="pre">asyncio</span></code> — Asynchronous I/O</a> &#187;</li>
        <li class="nav-item nav-item-this"><a href="">Extending</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 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 Mar 10, 2026 (08:58 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>