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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="X-UA-Compatible" content="IE=Edge" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>26.2. pydoc — Documentation generator and online help system — Python 3.6.7 documentation</title> <link rel="stylesheet" href="../_static/pydoctheme.css" type="text/css" /> <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> <script type="text/javascript" id="documentation_options" data-url_root="../" src="../_static/documentation_options.js"></script> <script type="text/javascript" src="../_static/jquery.js"></script> <script type="text/javascript" src="../_static/underscore.js"></script> <script type="text/javascript" src="../_static/doctools.js"></script> <script type="text/javascript" src="../_static/sidebar.js"></script> <link rel="search" type="application/opensearchdescription+xml" title="Search within Python 3.6.7 documentation" href="../_static/opensearch.xml"/> <link rel="author" title="About these documents" href="../about.html" /> <link rel="index" title="Index" href="../genindex.html" /> <link rel="search" title="Search" href="../search.html" /> <link rel="copyright" title="Copyright" href="../copyright.html" /> <link rel="next" title="26.3. doctest — Test interactive Python examples" href="doctest.html" /> <link rel="prev" title="26.1. typing — Support for type hints" href="typing.html" /> <link rel="shortcut icon" type="image/png" href="../_static/py.png" /> <link rel="canonical" href="https://docs.python.org/3/library/pydoc.html" /> <script type="text/javascript" src="../_static/copybutton.js"></script> </head><body> <div class="related" role="navigation" aria-label="related navigation"> <h3>Navigation</h3> <ul> <li class="right" style="margin-right: 10px"> <a href="../genindex.html" title="General Index" accesskey="I">index</a></li> <li class="right" > <a href="../py-modindex.html" title="Python Module Index" >modules</a> |</li> <li class="right" > <a href="doctest.html" title="26.3. doctest — Test interactive Python examples" accesskey="N">next</a> |</li> <li class="right" > <a href="typing.html" title="26.1. typing — Support for type hints" accesskey="P">previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="https://www.python.org/">Python</a> »</li> <li> <a href="../index.html">3.6.7 Documentation</a> » </li> <li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> »</li> <li class="nav-item nav-item-2"><a href="development.html" accesskey="U">26. Development Tools</a> »</li> <li class="right"> <div class="inline-search" style="display: none" role="search"> <form class="inline-search" action="../search.html" method="get"> <input placeholder="Quick search" type="text" name="q" /> <input type="submit" value="Go" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> </div> <script type="text/javascript">$('.inline-search').show(0);</script> | </li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body" role="main"> <div class="section" id="module-pydoc"> <span id="pydoc-documentation-generator-and-online-help-system"></span><h1>26.2. <a class="reference internal" href="#module-pydoc" title="pydoc: Documentation generator and online help system."><code class="xref py py-mod docutils literal notranslate"><span class="pre">pydoc</span></code></a> — Documentation generator and online help system<a class="headerlink" href="#module-pydoc" title="Permalink to this headline">¶</a></h1> <p><strong>Source code:</strong> <a class="reference external" href="https://github.com/python/cpython/tree/3.6/Lib/pydoc.py">Lib/pydoc.py</a></p> <hr class="docutils" id="index-0" /> <p>The <a class="reference internal" href="#module-pydoc" title="pydoc: Documentation generator and online help system."><code class="xref py py-mod docutils literal notranslate"><span class="pre">pydoc</span></code></a> module automatically generates documentation from Python modules. The documentation can be presented as pages of text on the console, served to a Web browser, or saved to HTML files.</p> <p>For modules, classes, functions and methods, the displayed documentation is derived from the docstring (i.e. the <code class="xref py py-attr docutils literal notranslate"><span class="pre">__doc__</span></code> attribute) of the object, and recursively of its documentable members. If there is no docstring, <a class="reference internal" href="#module-pydoc" title="pydoc: Documentation generator and online help system."><code class="xref py py-mod docutils literal notranslate"><span class="pre">pydoc</span></code></a> tries to obtain a description from the block of comment lines just above the definition of the class, function or method in the source file, or at the top of the module (see <a class="reference internal" href="inspect.html#inspect.getcomments" title="inspect.getcomments"><code class="xref py py-func docutils literal notranslate"><span class="pre">inspect.getcomments()</span></code></a>).</p> <p>The built-in function <a class="reference internal" href="functions.html#help" title="help"><code class="xref py py-func docutils literal notranslate"><span class="pre">help()</span></code></a> invokes the online help system in the interactive interpreter, which uses <a class="reference internal" href="#module-pydoc" title="pydoc: Documentation generator and online help system."><code class="xref py py-mod docutils literal notranslate"><span class="pre">pydoc</span></code></a> to generate its documentation as text on the console. The same text documentation can also be viewed from outside the Python interpreter by running <strong class="program">pydoc</strong> as a script at the operating system’s command prompt. For example, running</p> <div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="n">pydoc</span> <span class="n">sys</span> </pre></div> </div> <p>at a shell prompt will display documentation on the <a class="reference internal" href="sys.html#module-sys" title="sys: Access system-specific parameters and functions."><code class="xref py py-mod docutils literal notranslate"><span class="pre">sys</span></code></a> module, in a style similar to the manual pages shown by the Unix <strong class="program">man</strong> command. The argument to <strong class="program">pydoc</strong> can be the name of a function, module, or package, or a dotted reference to a class, method, or function within a module or module in a package. If the argument to <strong class="program">pydoc</strong> looks like a path (that is, it contains the path separator for your operating system, such as a slash in Unix), and refers to an existing Python source file, then documentation is produced for that file.</p> <div class="admonition note"> <p class="first admonition-title">Note</p> <p class="last">In order to find objects and their documentation, <a class="reference internal" href="#module-pydoc" title="pydoc: Documentation generator and online help system."><code class="xref py py-mod docutils literal notranslate"><span class="pre">pydoc</span></code></a> imports the module(s) to be documented. Therefore, any code on module level will be executed on that occasion. Use an <code class="docutils literal notranslate"><span class="pre">if</span> <span class="pre">__name__</span> <span class="pre">==</span> <span class="pre">'__main__':</span></code> guard to only execute code when a file is invoked as a script and not just imported.</p> </div> <p>When printing output to the console, <strong class="program">pydoc</strong> attempts to paginate the output for easier reading. If the <span class="target" id="index-1"></span><code class="xref std std-envvar docutils literal notranslate"><span class="pre">PAGER</span></code> environment variable is set, <strong class="program">pydoc</strong> will use its value as a pagination program.</p> <p>Specifying a <code class="docutils literal notranslate"><span class="pre">-w</span></code> flag before the argument will cause HTML documentation to be written out to a file in the current directory, instead of displaying text on the console.</p> <p>Specifying a <code class="docutils literal notranslate"><span class="pre">-k</span></code> flag before the argument will search the synopsis lines of all available modules for the keyword given as the argument, again in a manner similar to the Unix <strong class="program">man</strong> command. The synopsis line of a module is the first line of its documentation string.</p> <p>You can also use <strong class="program">pydoc</strong> to start an HTTP server on the local machine that will serve documentation to visiting Web browsers. <strong class="program">pydoc -p 1234</strong> will start a HTTP server on port 1234, allowing you to browse the documentation at <code class="docutils literal notranslate"><span class="pre">http://localhost:1234/</span></code> in your preferred Web browser. Specifying <code class="docutils literal notranslate"><span class="pre">0</span></code> as the port number will select an arbitrary unused port.</p> <p><strong class="program">pydoc -b</strong> will start the server and additionally open a web browser to a module index page. Each served page has a navigation bar at the top where you can <em>Get</em> help on an individual item, <em>Search</em> all modules with a keyword in their synopsis line, and go to the <em>Module index</em>, <em>Topics</em> and <em>Keywords</em> pages.</p> <p>When <strong class="program">pydoc</strong> generates documentation, it uses the current environment and path to locate modules. Thus, invoking <strong class="program">pydoc spam</strong> documents precisely the version of the module you would get if you started the Python interpreter and typed <code class="docutils literal notranslate"><span class="pre">import</span> <span class="pre">spam</span></code>.</p> <p>Module docs for core modules are assumed to reside in <code class="docutils literal notranslate"><span class="pre">https://docs.python.org/X.Y/library/</span></code> where <code class="docutils literal notranslate"><span class="pre">X</span></code> and <code class="docutils literal notranslate"><span class="pre">Y</span></code> are the major and minor version numbers of the Python interpreter. This can be overridden by setting the <span class="target" id="index-2"></span><code class="xref std std-envvar docutils literal notranslate"><span class="pre">PYTHONDOCS</span></code> environment variable to a different URL or to a local directory containing the Library Reference Manual pages.</p> <div class="versionchanged"> <p><span class="versionmodified">Changed in version 3.2: </span>Added the <code class="docutils literal notranslate"><span class="pre">-b</span></code> option.</p> </div> <div class="versionchanged"> <p><span class="versionmodified">Changed in version 3.3: </span>The <code class="docutils literal notranslate"><span class="pre">-g</span></code> command line option was removed.</p> </div> <div class="versionchanged"> <p><span class="versionmodified">Changed in version 3.4: </span><a class="reference internal" href="#module-pydoc" title="pydoc: Documentation generator and online help system."><code class="xref py py-mod docutils literal notranslate"><span class="pre">pydoc</span></code></a> now uses <a class="reference internal" href="inspect.html#inspect.signature" title="inspect.signature"><code class="xref py py-func docutils literal notranslate"><span class="pre">inspect.signature()</span></code></a> rather than <a class="reference internal" href="inspect.html#inspect.getfullargspec" title="inspect.getfullargspec"><code class="xref py py-func docutils literal notranslate"><span class="pre">inspect.getfullargspec()</span></code></a> to extract signature information from callables.</p> </div> </div> </div> </div> </div> <div class="sphinxsidebar" role="navigation" aria-label="main navigation"> <div class="sphinxsidebarwrapper"> <h4>Previous topic</h4> <p class="topless"><a href="typing.html" title="previous chapter">26.1. <code class="docutils literal notranslate"><span class="pre">typing</span></code> — Support for type hints</a></p> <h4>Next topic</h4> <p class="topless"><a href="doctest.html" title="next chapter">26.3. <code class="docutils literal notranslate"><span class="pre">doctest</span></code> — Test interactive Python examples</a></p> <div role="note" aria-label="source link"> <h3>This Page</h3> <ul class="this-page-menu"> <li><a href="../bugs.html">Report a Bug</a></li> <li> <a href="https://github.com/python/cpython/blob/3.6/Doc/library/pydoc.rst" rel="nofollow">Show Source </a> </li> </ul> </div> </div> </div> <div class="clearer"></div> </div> <div class="related" role="navigation" aria-label="related navigation"> <h3>Navigation</h3> <ul> <li class="right" style="margin-right: 10px"> <a href="../genindex.html" title="General Index" >index</a></li> <li class="right" > <a href="../py-modindex.html" title="Python Module Index" >modules</a> |</li> <li class="right" > <a href="doctest.html" title="26.3. doctest — Test interactive Python examples" >next</a> |</li> <li class="right" > <a href="typing.html" title="26.1. typing — Support for type hints" >previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="https://www.python.org/">Python</a> »</li> <li> <a href="../index.html">3.6.7 Documentation</a> » </li> <li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> »</li> <li class="nav-item nav-item-2"><a href="development.html" >26. Development Tools</a> »</li> <li class="right"> <div class="inline-search" style="display: none" role="search"> <form class="inline-search" action="../search.html" method="get"> <input placeholder="Quick search" type="text" name="q" /> <input type="submit" value="Go" /> <input type="hidden" name="check_keywords" value="yes" /> <input type="hidden" name="area" value="default" /> </form> </div> <script type="text/javascript">$('.inline-search').show(0);</script> | </li> </ul> </div> <div class="footer"> © <a href="../copyright.html">Copyright</a> 2001-2023, Python Software Foundation. <br /> The Python Software Foundation is a non-profit corporation. <a href="https://www.python.org/psf/donations/">Please donate.</a> <br /> Last updated on Dec 18, 2023. <a href="../bugs.html">Found a bug</a>? <br /> Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 1.7.6. </div> </body> </html>
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[-] fileinput.html
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[-] binascii.html
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[-] quopri.html
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[-] copyreg.html
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[-] unix.html
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[-] _thread.html
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[-] custominterp.html
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[-] misc.html
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[-] persistence.html
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[-] winreg.html
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[-] unittest.html
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[-] dummy_threading.html
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[-] asyncio-task.html
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