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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>20.10. xml.sax.handler — Base classes for SAX handlers — 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="20.11. xml.sax.saxutils — SAX Utilities" href="xml.sax.utils.html" /> <link rel="prev" title="20.9. xml.sax — Support for SAX2 parsers" href="xml.sax.html" /> <link rel="shortcut icon" type="image/png" href="../_static/py.png" /> <link rel="canonical" href="https://docs.python.org/3/library/xml.sax.handler.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="xml.sax.utils.html" title="20.11. xml.sax.saxutils — SAX Utilities" accesskey="N">next</a> |</li> <li class="right" > <a href="xml.sax.html" title="20.9. xml.sax — Support for SAX2 parsers" 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="markup.html" accesskey="U">20. Structured Markup Processing 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-xml.sax.handler"> <span id="xml-sax-handler-base-classes-for-sax-handlers"></span><h1>20.10. <a class="reference internal" href="#module-xml.sax.handler" title="xml.sax.handler: Base classes for SAX event handlers."><code class="xref py py-mod docutils literal notranslate"><span class="pre">xml.sax.handler</span></code></a> — Base classes for SAX handlers<a class="headerlink" href="#module-xml.sax.handler" 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/xml/sax/handler.py">Lib/xml/sax/handler.py</a></p> <hr class="docutils" /> <p>The SAX API defines four kinds of handlers: content handlers, DTD handlers, error handlers, and entity resolvers. Applications normally only need to implement those interfaces whose events they are interested in; they can implement the interfaces in a single object or in multiple objects. Handler implementations should inherit from the base classes provided in the module <a class="reference internal" href="#module-xml.sax.handler" title="xml.sax.handler: Base classes for SAX event handlers."><code class="xref py py-mod docutils literal notranslate"><span class="pre">xml.sax.handler</span></code></a>, so that all methods get default implementations.</p> <dl class="class"> <dt id="xml.sax.handler.ContentHandler"> <em class="property">class </em><code class="descclassname">xml.sax.handler.</code><code class="descname">ContentHandler</code><a class="headerlink" href="#xml.sax.handler.ContentHandler" title="Permalink to this definition">¶</a></dt> <dd><p>This is the main callback interface in SAX, and the one most important to applications. The order of events in this interface mirrors the order of the information in the document.</p> </dd></dl> <dl class="class"> <dt id="xml.sax.handler.DTDHandler"> <em class="property">class </em><code class="descclassname">xml.sax.handler.</code><code class="descname">DTDHandler</code><a class="headerlink" href="#xml.sax.handler.DTDHandler" title="Permalink to this definition">¶</a></dt> <dd><p>Handle DTD events.</p> <p>This interface specifies only those DTD events required for basic parsing (unparsed entities and attributes).</p> </dd></dl> <dl class="class"> <dt id="xml.sax.handler.EntityResolver"> <em class="property">class </em><code class="descclassname">xml.sax.handler.</code><code class="descname">EntityResolver</code><a class="headerlink" href="#xml.sax.handler.EntityResolver" title="Permalink to this definition">¶</a></dt> <dd><p>Basic interface for resolving entities. If you create an object implementing this interface, then register the object with your Parser, the parser will call the method in your object to resolve all external entities.</p> </dd></dl> <dl class="class"> <dt id="xml.sax.handler.ErrorHandler"> <em class="property">class </em><code class="descclassname">xml.sax.handler.</code><code class="descname">ErrorHandler</code><a class="headerlink" href="#xml.sax.handler.ErrorHandler" title="Permalink to this definition">¶</a></dt> <dd><p>Interface used by the parser to present error and warning messages to the application. The methods of this object control whether errors are immediately converted to exceptions or are handled in some other way.</p> </dd></dl> <p>In addition to these classes, <a class="reference internal" href="#module-xml.sax.handler" title="xml.sax.handler: Base classes for SAX event handlers."><code class="xref py py-mod docutils literal notranslate"><span class="pre">xml.sax.handler</span></code></a> provides symbolic constants for the feature and property names.</p> <dl class="data"> <dt id="xml.sax.handler.feature_namespaces"> <code class="descclassname">xml.sax.handler.</code><code class="descname">feature_namespaces</code><a class="headerlink" href="#xml.sax.handler.feature_namespaces" title="Permalink to this definition">¶</a></dt> <dd><div class="line-block"> <div class="line">value: <code class="docutils literal notranslate"><span class="pre">"http://xml.org/sax/features/namespaces"</span></code></div> <div class="line">true: Perform Namespace processing.</div> <div class="line">false: Optionally do not perform Namespace processing (implies namespace-prefixes; default).</div> <div class="line">access: (parsing) read-only; (not parsing) read/write</div> </div> </dd></dl> <dl class="data"> <dt id="xml.sax.handler.feature_namespace_prefixes"> <code class="descclassname">xml.sax.handler.</code><code class="descname">feature_namespace_prefixes</code><a class="headerlink" href="#xml.sax.handler.feature_namespace_prefixes" title="Permalink to this definition">¶</a></dt> <dd><div class="line-block"> <div class="line">value: <code class="docutils literal notranslate"><span class="pre">"http://xml.org/sax/features/namespace-prefixes"</span></code></div> <div class="line">true: Report the original prefixed names and attributes used for Namespace declarations.</div> <div class="line">false: Do not report attributes used for Namespace declarations, and optionally do not report original prefixed names (default).</div> <div class="line">access: (parsing) read-only; (not parsing) read/write</div> </div> </dd></dl> <dl class="data"> <dt id="xml.sax.handler.feature_string_interning"> <code class="descclassname">xml.sax.handler.</code><code class="descname">feature_string_interning</code><a class="headerlink" href="#xml.sax.handler.feature_string_interning" title="Permalink to this definition">¶</a></dt> <dd><div class="line-block"> <div class="line">value: <code class="docutils literal notranslate"><span class="pre">"http://xml.org/sax/features/string-interning"</span></code></div> <div class="line">true: All element names, prefixes, attribute names, Namespace URIs, and local names are interned using the built-in intern function.</div> <div class="line">false: Names are not necessarily interned, although they may be (default).</div> <div class="line">access: (parsing) read-only; (not parsing) read/write</div> </div> </dd></dl> <dl class="data"> <dt id="xml.sax.handler.feature_validation"> <code class="descclassname">xml.sax.handler.</code><code class="descname">feature_validation</code><a class="headerlink" href="#xml.sax.handler.feature_validation" title="Permalink to this definition">¶</a></dt> <dd><div class="line-block"> <div class="line">value: <code class="docutils literal notranslate"><span class="pre">"http://xml.org/sax/features/validation"</span></code></div> <div class="line">true: Report all validation errors (implies external-general-entities and external-parameter-entities).</div> <div class="line">false: Do not report validation errors.</div> <div class="line">access: (parsing) read-only; (not parsing) read/write</div> </div> </dd></dl> <dl class="data"> <dt id="xml.sax.handler.feature_external_ges"> <code class="descclassname">xml.sax.handler.</code><code class="descname">feature_external_ges</code><a class="headerlink" href="#xml.sax.handler.feature_external_ges" title="Permalink to this definition">¶</a></dt> <dd><div class="line-block"> <div class="line">value: <code class="docutils literal notranslate"><span class="pre">"http://xml.org/sax/features/external-general-entities"</span></code></div> <div class="line">true: Include all external general (text) entities.</div> <div class="line">false: Do not include external general entities.</div> <div class="line">access: (parsing) read-only; (not parsing) read/write</div> </div> </dd></dl> <dl class="data"> <dt id="xml.sax.handler.feature_external_pes"> <code class="descclassname">xml.sax.handler.</code><code class="descname">feature_external_pes</code><a class="headerlink" href="#xml.sax.handler.feature_external_pes" title="Permalink to this definition">¶</a></dt> <dd><div class="line-block"> <div class="line">value: <code class="docutils literal notranslate"><span class="pre">"http://xml.org/sax/features/external-parameter-entities"</span></code></div> <div class="line">true: Include all external parameter entities, including the external DTD subset.</div> <div class="line">false: Do not include any external parameter entities, even the external DTD subset.</div> <div class="line">access: (parsing) read-only; (not parsing) read/write</div> </div> </dd></dl> <dl class="data"> <dt id="xml.sax.handler.all_features"> <code class="descclassname">xml.sax.handler.</code><code class="descname">all_features</code><a class="headerlink" href="#xml.sax.handler.all_features" title="Permalink to this definition">¶</a></dt> <dd><p>List of all features.</p> </dd></dl> <dl class="data"> <dt id="xml.sax.handler.property_lexical_handler"> <code class="descclassname">xml.sax.handler.</code><code class="descname">property_lexical_handler</code><a class="headerlink" href="#xml.sax.handler.property_lexical_handler" title="Permalink to this definition">¶</a></dt> <dd><div class="line-block"> <div class="line">value: <code class="docutils literal notranslate"><span class="pre">"http://xml.org/sax/properties/lexical-handler"</span></code></div> <div class="line">data type: xml.sax.sax2lib.LexicalHandler (not supported in Python 2)</div> <div class="line">description: An optional extension handler for lexical events like comments.</div> <div class="line">access: read/write</div> </div> </dd></dl> <dl class="data"> <dt id="xml.sax.handler.property_declaration_handler"> <code class="descclassname">xml.sax.handler.</code><code class="descname">property_declaration_handler</code><a class="headerlink" href="#xml.sax.handler.property_declaration_handler" title="Permalink to this definition">¶</a></dt> <dd><div class="line-block"> <div class="line">value: <code class="docutils literal notranslate"><span class="pre">"http://xml.org/sax/properties/declaration-handler"</span></code></div> <div class="line">data type: xml.sax.sax2lib.DeclHandler (not supported in Python 2)</div> <div class="line">description: An optional extension handler for DTD-related events other than notations and unparsed entities.</div> <div class="line">access: read/write</div> </div> </dd></dl> <dl class="data"> <dt id="xml.sax.handler.property_dom_node"> <code class="descclassname">xml.sax.handler.</code><code class="descname">property_dom_node</code><a class="headerlink" href="#xml.sax.handler.property_dom_node" title="Permalink to this definition">¶</a></dt> <dd><div class="line-block"> <div class="line">value: <code class="docutils literal notranslate"><span class="pre">"http://xml.org/sax/properties/dom-node"</span></code></div> <div class="line">data type: org.w3c.dom.Node (not supported in Python 2)</div> <div class="line">description: When parsing, the current DOM node being visited if this is a DOM iterator; when not parsing, the root DOM node for iteration.</div> <div class="line">access: (parsing) read-only; (not parsing) read/write</div> </div> </dd></dl> <dl class="data"> <dt id="xml.sax.handler.property_xml_string"> <code class="descclassname">xml.sax.handler.</code><code class="descname">property_xml_string</code><a class="headerlink" href="#xml.sax.handler.property_xml_string" title="Permalink to this definition">¶</a></dt> <dd><div class="line-block"> <div class="line">value: <code class="docutils literal notranslate"><span class="pre">"http://xml.org/sax/properties/xml-string"</span></code></div> <div class="line">data type: String</div> <div class="line">description: The literal string of characters that was the source for the current event.</div> <div class="line">access: read-only</div> </div> </dd></dl> <dl class="data"> <dt id="xml.sax.handler.all_properties"> <code class="descclassname">xml.sax.handler.</code><code class="descname">all_properties</code><a class="headerlink" href="#xml.sax.handler.all_properties" title="Permalink to this definition">¶</a></dt> <dd><p>List of all known property names.</p> </dd></dl> <div class="section" id="contenthandler-objects"> <span id="content-handler-objects"></span><h2>20.10.1. ContentHandler Objects<a class="headerlink" href="#contenthandler-objects" title="Permalink to this headline">¶</a></h2> <p>Users are expected to subclass <a class="reference internal" href="#xml.sax.handler.ContentHandler" title="xml.sax.handler.ContentHandler"><code class="xref py py-class docutils literal notranslate"><span class="pre">ContentHandler</span></code></a> to support their application. The following methods are called by the parser on the appropriate events in the input document:</p> <dl class="method"> <dt id="xml.sax.handler.ContentHandler.setDocumentLocator"> <code class="descclassname">ContentHandler.</code><code class="descname">setDocumentLocator</code><span class="sig-paren">(</span><em>locator</em><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.ContentHandler.setDocumentLocator" title="Permalink to this definition">¶</a></dt> <dd><p>Called by the parser to give the application a locator for locating the origin of document events.</p> <p>SAX parsers are strongly encouraged (though not absolutely required) to supply a locator: if it does so, it must supply the locator to the application by invoking this method before invoking any of the other methods in the DocumentHandler interface.</p> <p>The locator allows the application to determine the end position of any document-related event, even if the parser is not reporting an error. Typically, the application will use this information for reporting its own errors (such as character content that does not match an application’s business rules). The information returned by the locator is probably not sufficient for use with a search engine.</p> <p>Note that the locator will return correct information only during the invocation of the events in this interface. The application should not attempt to use it at any other time.</p> </dd></dl> <dl class="method"> <dt id="xml.sax.handler.ContentHandler.startDocument"> <code class="descclassname">ContentHandler.</code><code class="descname">startDocument</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.ContentHandler.startDocument" title="Permalink to this definition">¶</a></dt> <dd><p>Receive notification of the beginning of a document.</p> <p>The SAX parser will invoke this method only once, before any other methods in this interface or in DTDHandler (except for <a class="reference internal" href="#xml.sax.handler.ContentHandler.setDocumentLocator" title="xml.sax.handler.ContentHandler.setDocumentLocator"><code class="xref py py-meth docutils literal notranslate"><span class="pre">setDocumentLocator()</span></code></a>).</p> </dd></dl> <dl class="method"> <dt id="xml.sax.handler.ContentHandler.endDocument"> <code class="descclassname">ContentHandler.</code><code class="descname">endDocument</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.ContentHandler.endDocument" title="Permalink to this definition">¶</a></dt> <dd><p>Receive notification of the end of a document.</p> <p>The SAX parser will invoke this method only once, and it will be the last method invoked during the parse. The parser shall not invoke this method until it has either abandoned parsing (because of an unrecoverable error) or reached the end of input.</p> </dd></dl> <dl class="method"> <dt id="xml.sax.handler.ContentHandler.startPrefixMapping"> <code class="descclassname">ContentHandler.</code><code class="descname">startPrefixMapping</code><span class="sig-paren">(</span><em>prefix</em>, <em>uri</em><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.ContentHandler.startPrefixMapping" title="Permalink to this definition">¶</a></dt> <dd><p>Begin the scope of a prefix-URI Namespace mapping.</p> <p>The information from this event is not necessary for normal Namespace processing: the SAX XML reader will automatically replace prefixes for element and attribute names when the <code class="docutils literal notranslate"><span class="pre">feature_namespaces</span></code> feature is enabled (the default).</p> <p>There are cases, however, when applications need to use prefixes in character data or in attribute values, where they cannot safely be expanded automatically; the <a class="reference internal" href="#xml.sax.handler.ContentHandler.startPrefixMapping" title="xml.sax.handler.ContentHandler.startPrefixMapping"><code class="xref py py-meth docutils literal notranslate"><span class="pre">startPrefixMapping()</span></code></a> and <a class="reference internal" href="#xml.sax.handler.ContentHandler.endPrefixMapping" title="xml.sax.handler.ContentHandler.endPrefixMapping"><code class="xref py py-meth docutils literal notranslate"><span class="pre">endPrefixMapping()</span></code></a> events supply the information to the application to expand prefixes in those contexts itself, if necessary.</p> <p>Note that <a class="reference internal" href="#xml.sax.handler.ContentHandler.startPrefixMapping" title="xml.sax.handler.ContentHandler.startPrefixMapping"><code class="xref py py-meth docutils literal notranslate"><span class="pre">startPrefixMapping()</span></code></a> and <a class="reference internal" href="#xml.sax.handler.ContentHandler.endPrefixMapping" title="xml.sax.handler.ContentHandler.endPrefixMapping"><code class="xref py py-meth docutils literal notranslate"><span class="pre">endPrefixMapping()</span></code></a> events are not guaranteed to be properly nested relative to each-other: all <a class="reference internal" href="#xml.sax.handler.ContentHandler.startPrefixMapping" title="xml.sax.handler.ContentHandler.startPrefixMapping"><code class="xref py py-meth docutils literal notranslate"><span class="pre">startPrefixMapping()</span></code></a> events will occur before the corresponding <a class="reference internal" href="#xml.sax.handler.ContentHandler.startElement" title="xml.sax.handler.ContentHandler.startElement"><code class="xref py py-meth docutils literal notranslate"><span class="pre">startElement()</span></code></a> event, and all <a class="reference internal" href="#xml.sax.handler.ContentHandler.endPrefixMapping" title="xml.sax.handler.ContentHandler.endPrefixMapping"><code class="xref py py-meth docutils literal notranslate"><span class="pre">endPrefixMapping()</span></code></a> events will occur after the corresponding <a class="reference internal" href="#xml.sax.handler.ContentHandler.endElement" title="xml.sax.handler.ContentHandler.endElement"><code class="xref py py-meth docutils literal notranslate"><span class="pre">endElement()</span></code></a> event, but their order is not guaranteed.</p> </dd></dl> <dl class="method"> <dt id="xml.sax.handler.ContentHandler.endPrefixMapping"> <code class="descclassname">ContentHandler.</code><code class="descname">endPrefixMapping</code><span class="sig-paren">(</span><em>prefix</em><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.ContentHandler.endPrefixMapping" title="Permalink to this definition">¶</a></dt> <dd><p>End the scope of a prefix-URI mapping.</p> <p>See <a class="reference internal" href="#xml.sax.handler.ContentHandler.startPrefixMapping" title="xml.sax.handler.ContentHandler.startPrefixMapping"><code class="xref py py-meth docutils literal notranslate"><span class="pre">startPrefixMapping()</span></code></a> for details. This event will always occur after the corresponding <a class="reference internal" href="#xml.sax.handler.ContentHandler.endElement" title="xml.sax.handler.ContentHandler.endElement"><code class="xref py py-meth docutils literal notranslate"><span class="pre">endElement()</span></code></a> event, but the order of <a class="reference internal" href="#xml.sax.handler.ContentHandler.endPrefixMapping" title="xml.sax.handler.ContentHandler.endPrefixMapping"><code class="xref py py-meth docutils literal notranslate"><span class="pre">endPrefixMapping()</span></code></a> events is not otherwise guaranteed.</p> </dd></dl> <dl class="method"> <dt id="xml.sax.handler.ContentHandler.startElement"> <code class="descclassname">ContentHandler.</code><code class="descname">startElement</code><span class="sig-paren">(</span><em>name</em>, <em>attrs</em><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.ContentHandler.startElement" title="Permalink to this definition">¶</a></dt> <dd><p>Signals the start of an element in non-namespace mode.</p> <p>The <em>name</em> parameter contains the raw XML 1.0 name of the element type as a string and the <em>attrs</em> parameter holds an object of the <code class="xref py py-class docutils literal notranslate"><span class="pre">Attributes</span></code> interface (see <a class="reference internal" href="xml.sax.reader.html#attributes-objects"><span class="std std-ref">The Attributes Interface</span></a>) containing the attributes of the element. The object passed as <em>attrs</em> may be re-used by the parser; holding on to a reference to it is not a reliable way to keep a copy of the attributes. To keep a copy of the attributes, use the <a class="reference internal" href="copy.html#module-copy" title="copy: Shallow and deep copy operations."><code class="xref py py-meth docutils literal notranslate"><span class="pre">copy()</span></code></a> method of the <em>attrs</em> object.</p> </dd></dl> <dl class="method"> <dt id="xml.sax.handler.ContentHandler.endElement"> <code class="descclassname">ContentHandler.</code><code class="descname">endElement</code><span class="sig-paren">(</span><em>name</em><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.ContentHandler.endElement" title="Permalink to this definition">¶</a></dt> <dd><p>Signals the end of an element in non-namespace mode.</p> <p>The <em>name</em> parameter contains the name of the element type, just as with the <a class="reference internal" href="#xml.sax.handler.ContentHandler.startElement" title="xml.sax.handler.ContentHandler.startElement"><code class="xref py py-meth docutils literal notranslate"><span class="pre">startElement()</span></code></a> event.</p> </dd></dl> <dl class="method"> <dt id="xml.sax.handler.ContentHandler.startElementNS"> <code class="descclassname">ContentHandler.</code><code class="descname">startElementNS</code><span class="sig-paren">(</span><em>name</em>, <em>qname</em>, <em>attrs</em><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.ContentHandler.startElementNS" title="Permalink to this definition">¶</a></dt> <dd><p>Signals the start of an element in namespace mode.</p> <p>The <em>name</em> parameter contains the name of the element type as a <code class="docutils literal notranslate"><span class="pre">(uri,</span> <span class="pre">localname)</span></code> tuple, the <em>qname</em> parameter contains the raw XML 1.0 name used in the source document, and the <em>attrs</em> parameter holds an instance of the <code class="xref py py-class docutils literal notranslate"><span class="pre">AttributesNS</span></code> interface (see <a class="reference internal" href="xml.sax.reader.html#attributes-ns-objects"><span class="std std-ref">The AttributesNS Interface</span></a>) containing the attributes of the element. If no namespace is associated with the element, the <em>uri</em> component of <em>name</em> will be <code class="docutils literal notranslate"><span class="pre">None</span></code>. The object passed as <em>attrs</em> may be re-used by the parser; holding on to a reference to it is not a reliable way to keep a copy of the attributes. To keep a copy of the attributes, use the <a class="reference internal" href="copy.html#module-copy" title="copy: Shallow and deep copy operations."><code class="xref py py-meth docutils literal notranslate"><span class="pre">copy()</span></code></a> method of the <em>attrs</em> object.</p> <p>Parsers may set the <em>qname</em> parameter to <code class="docutils literal notranslate"><span class="pre">None</span></code>, unless the <code class="docutils literal notranslate"><span class="pre">feature_namespace_prefixes</span></code> feature is activated.</p> </dd></dl> <dl class="method"> <dt id="xml.sax.handler.ContentHandler.endElementNS"> <code class="descclassname">ContentHandler.</code><code class="descname">endElementNS</code><span class="sig-paren">(</span><em>name</em>, <em>qname</em><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.ContentHandler.endElementNS" title="Permalink to this definition">¶</a></dt> <dd><p>Signals the end of an element in namespace mode.</p> <p>The <em>name</em> parameter contains the name of the element type, just as with the <a class="reference internal" href="#xml.sax.handler.ContentHandler.startElementNS" title="xml.sax.handler.ContentHandler.startElementNS"><code class="xref py py-meth docutils literal notranslate"><span class="pre">startElementNS()</span></code></a> method, likewise the <em>qname</em> parameter.</p> </dd></dl> <dl class="method"> <dt id="xml.sax.handler.ContentHandler.characters"> <code class="descclassname">ContentHandler.</code><code class="descname">characters</code><span class="sig-paren">(</span><em>content</em><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.ContentHandler.characters" title="Permalink to this definition">¶</a></dt> <dd><p>Receive notification of character data.</p> <p>The Parser will call this method to report each chunk of character data. SAX parsers may return all contiguous character data in a single chunk, or they may split it into several chunks; however, all of the characters in any single event must come from the same external entity so that the Locator provides useful information.</p> <p><em>content</em> may be a string or bytes instance; the <code class="docutils literal notranslate"><span class="pre">expat</span></code> reader module always produces strings.</p> <div class="admonition note"> <p class="first admonition-title">Note</p> <p class="last">The earlier SAX 1 interface provided by the Python XML Special Interest Group used a more Java-like interface for this method. Since most parsers used from Python did not take advantage of the older interface, the simpler signature was chosen to replace it. To convert old code to the new interface, use <em>content</em> instead of slicing content with the old <em>offset</em> and <em>length</em> parameters.</p> </div> </dd></dl> <dl class="method"> <dt id="xml.sax.handler.ContentHandler.ignorableWhitespace"> <code class="descclassname">ContentHandler.</code><code class="descname">ignorableWhitespace</code><span class="sig-paren">(</span><em>whitespace</em><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.ContentHandler.ignorableWhitespace" title="Permalink to this definition">¶</a></dt> <dd><p>Receive notification of ignorable whitespace in element content.</p> <p>Validating Parsers must use this method to report each chunk of ignorable whitespace (see the W3C XML 1.0 recommendation, section 2.10): non-validating parsers may also use this method if they are capable of parsing and using content models.</p> <p>SAX parsers may return all contiguous whitespace in a single chunk, or they may split it into several chunks; however, all of the characters in any single event must come from the same external entity, so that the Locator provides useful information.</p> </dd></dl> <dl class="method"> <dt id="xml.sax.handler.ContentHandler.processingInstruction"> <code class="descclassname">ContentHandler.</code><code class="descname">processingInstruction</code><span class="sig-paren">(</span><em>target</em>, <em>data</em><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.ContentHandler.processingInstruction" title="Permalink to this definition">¶</a></dt> <dd><p>Receive notification of a processing instruction.</p> <p>The Parser will invoke this method once for each processing instruction found: note that processing instructions may occur before or after the main document element.</p> <p>A SAX parser should never report an XML declaration (XML 1.0, section 2.8) or a text declaration (XML 1.0, section 4.3.1) using this method.</p> </dd></dl> <dl class="method"> <dt id="xml.sax.handler.ContentHandler.skippedEntity"> <code class="descclassname">ContentHandler.</code><code class="descname">skippedEntity</code><span class="sig-paren">(</span><em>name</em><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.ContentHandler.skippedEntity" title="Permalink to this definition">¶</a></dt> <dd><p>Receive notification of a skipped entity.</p> <p>The Parser will invoke this method once for each entity skipped. Non-validating processors may skip entities if they have not seen the declarations (because, for example, the entity was declared in an external DTD subset). All processors may skip external entities, depending on the values of the <code class="docutils literal notranslate"><span class="pre">feature_external_ges</span></code> and the <code class="docutils literal notranslate"><span class="pre">feature_external_pes</span></code> properties.</p> </dd></dl> </div> <div class="section" id="dtdhandler-objects"> <span id="dtd-handler-objects"></span><h2>20.10.2. DTDHandler Objects<a class="headerlink" href="#dtdhandler-objects" title="Permalink to this headline">¶</a></h2> <p><a class="reference internal" href="#xml.sax.handler.DTDHandler" title="xml.sax.handler.DTDHandler"><code class="xref py py-class docutils literal notranslate"><span class="pre">DTDHandler</span></code></a> instances provide the following methods:</p> <dl class="method"> <dt id="xml.sax.handler.DTDHandler.notationDecl"> <code class="descclassname">DTDHandler.</code><code class="descname">notationDecl</code><span class="sig-paren">(</span><em>name</em>, <em>publicId</em>, <em>systemId</em><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.DTDHandler.notationDecl" title="Permalink to this definition">¶</a></dt> <dd><p>Handle a notation declaration event.</p> </dd></dl> <dl class="method"> <dt id="xml.sax.handler.DTDHandler.unparsedEntityDecl"> <code class="descclassname">DTDHandler.</code><code class="descname">unparsedEntityDecl</code><span class="sig-paren">(</span><em>name</em>, <em>publicId</em>, <em>systemId</em>, <em>ndata</em><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.DTDHandler.unparsedEntityDecl" title="Permalink to this definition">¶</a></dt> <dd><p>Handle an unparsed entity declaration event.</p> </dd></dl> </div> <div class="section" id="entityresolver-objects"> <span id="entity-resolver-objects"></span><h2>20.10.3. EntityResolver Objects<a class="headerlink" href="#entityresolver-objects" title="Permalink to this headline">¶</a></h2> <dl class="method"> <dt id="xml.sax.handler.EntityResolver.resolveEntity"> <code class="descclassname">EntityResolver.</code><code class="descname">resolveEntity</code><span class="sig-paren">(</span><em>publicId</em>, <em>systemId</em><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.EntityResolver.resolveEntity" title="Permalink to this definition">¶</a></dt> <dd><p>Resolve the system identifier of an entity and return either the system identifier to read from as a string, or an InputSource to read from. The default implementation returns <em>systemId</em>.</p> </dd></dl> </div> <div class="section" id="errorhandler-objects"> <span id="sax-error-handler"></span><h2>20.10.4. ErrorHandler Objects<a class="headerlink" href="#errorhandler-objects" title="Permalink to this headline">¶</a></h2> <p>Objects with this interface are used to receive error and warning information from the <a class="reference internal" href="xml.sax.reader.html#xml.sax.xmlreader.XMLReader" title="xml.sax.xmlreader.XMLReader"><code class="xref py py-class docutils literal notranslate"><span class="pre">XMLReader</span></code></a>. If you create an object that implements this interface, then register the object with your <a class="reference internal" href="xml.sax.reader.html#xml.sax.xmlreader.XMLReader" title="xml.sax.xmlreader.XMLReader"><code class="xref py py-class docutils literal notranslate"><span class="pre">XMLReader</span></code></a>, the parser will call the methods in your object to report all warnings and errors. There are three levels of errors available: warnings, (possibly) recoverable errors, and unrecoverable errors. All methods take a <code class="xref py py-exc docutils literal notranslate"><span class="pre">SAXParseException</span></code> as the only parameter. Errors and warnings may be converted to an exception by raising the passed-in exception object.</p> <dl class="method"> <dt id="xml.sax.handler.ErrorHandler.error"> <code class="descclassname">ErrorHandler.</code><code class="descname">error</code><span class="sig-paren">(</span><em>exception</em><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.ErrorHandler.error" title="Permalink to this definition">¶</a></dt> <dd><p>Called when the parser encounters a recoverable error. If this method does not raise an exception, parsing may continue, but further document information should not be expected by the application. Allowing the parser to continue may allow additional errors to be discovered in the input document.</p> </dd></dl> <dl class="method"> <dt id="xml.sax.handler.ErrorHandler.fatalError"> <code class="descclassname">ErrorHandler.</code><code class="descname">fatalError</code><span class="sig-paren">(</span><em>exception</em><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.ErrorHandler.fatalError" title="Permalink to this definition">¶</a></dt> <dd><p>Called when the parser encounters an error it cannot recover from; parsing is expected to terminate when this method returns.</p> </dd></dl> <dl class="method"> <dt id="xml.sax.handler.ErrorHandler.warning"> <code class="descclassname">ErrorHandler.</code><code class="descname">warning</code><span class="sig-paren">(</span><em>exception</em><span class="sig-paren">)</span><a class="headerlink" href="#xml.sax.handler.ErrorHandler.warning" title="Permalink to this definition">¶</a></dt> <dd><p>Called when the parser presents minor warning information to the application. Parsing is expected to continue when this method returns, and document information will continue to be passed to the application. Raising an exception in this method will cause parsing to end.</p> </dd></dl> </div> </div> </div> </div> </div> <div class="sphinxsidebar" role="navigation" aria-label="main navigation"> <div class="sphinxsidebarwrapper"> <h3><a href="../contents.html">Table Of Contents</a></h3> <ul> <li><a class="reference internal" href="#">20.10. <code class="docutils literal notranslate"><span class="pre">xml.sax.handler</span></code> — Base classes for SAX handlers</a><ul> <li><a class="reference internal" href="#contenthandler-objects">20.10.1. ContentHandler Objects</a></li> <li><a class="reference internal" href="#dtdhandler-objects">20.10.2. DTDHandler Objects</a></li> <li><a class="reference internal" href="#entityresolver-objects">20.10.3. EntityResolver Objects</a></li> <li><a class="reference internal" href="#errorhandler-objects">20.10.4. ErrorHandler Objects</a></li> </ul> </li> </ul> <h4>Previous topic</h4> <p class="topless"><a href="xml.sax.html" title="previous chapter">20.9. <code class="docutils literal notranslate"><span class="pre">xml.sax</span></code> — Support for SAX2 parsers</a></p> <h4>Next topic</h4> <p class="topless"><a href="xml.sax.utils.html" title="next chapter">20.11. <code class="docutils literal notranslate"><span class="pre">xml.sax.saxutils</span></code> — SAX Utilities</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/xml.sax.handler.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="xml.sax.utils.html" title="20.11. xml.sax.saxutils — SAX Utilities" >next</a> |</li> <li class="right" > <a href="xml.sax.html" title="20.9. xml.sax — Support for SAX2 parsers" >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="markup.html" >20. 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