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Structured Markup Processing Tools</a> »</li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body"> <div class="section" id="module-xml.sax"> <span id="xml-sax-support-for-sax2-parsers"></span><h1>19.11. <a class="reference internal" href="#module-xml.sax" title="xml.sax: Package containing SAX2 base classes and convenience functions."><tt class="xref py py-mod docutils literal"><span class="pre">xml.sax</span></tt></a> — Support for SAX2 parsers<a class="headerlink" href="#module-xml.sax" title="Permalink to this headline">¶</a></h1> <p class="versionadded"> <span class="versionmodified">New in version 2.0.</span></p> <p>The <a class="reference internal" href="#module-xml.sax" title="xml.sax: Package containing SAX2 base classes and convenience functions."><tt class="xref py py-mod docutils literal"><span class="pre">xml.sax</span></tt></a> package provides a number of modules which implement the Simple API for XML (SAX) interface for Python. The package itself provides the SAX exceptions and the convenience functions which will be most used by users of the SAX API.</p> <div class="admonition warning"> <p class="first admonition-title">Warning</p> <p class="last">The <a class="reference internal" href="#module-xml.sax" title="xml.sax: Package containing SAX2 base classes and convenience functions."><tt class="xref py py-mod docutils literal"><span class="pre">xml.sax</span></tt></a> module is not secure against maliciously constructed data. If you need to parse untrusted or unauthenticated data see <a class="reference internal" href="xml.html#xml-vulnerabilities"><em>XML vulnerabilities</em></a>.</p> </div> <p>The convenience functions are:</p> <dl class="function"> <dt id="xml.sax.make_parser"> <tt class="descclassname">xml.sax.</tt><tt class="descname">make_parser</tt><big>(</big><span class="optional">[</span><em>parser_list</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#xml.sax.make_parser" title="Permalink to this definition">¶</a></dt> <dd><p>Create and return a SAX <tt class="xref py py-class docutils literal"><span class="pre">XMLReader</span></tt> object. The first parser found will be used. If <em>parser_list</em> is provided, it must be a sequence of strings which name modules that have a function named <tt class="xref py py-func docutils literal"><span class="pre">create_parser()</span></tt>. Modules listed in <em>parser_list</em> will be used before modules in the default list of parsers.</p> </dd></dl> <dl class="function"> <dt id="xml.sax.parse"> <tt class="descclassname">xml.sax.</tt><tt class="descname">parse</tt><big>(</big><em>filename_or_stream</em>, <em>handler</em><span class="optional">[</span>, <em>error_handler</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#xml.sax.parse" title="Permalink to this definition">¶</a></dt> <dd><p>Create a SAX parser and use it to parse a document. The document, passed in as <em>filename_or_stream</em>, can be a filename or a file object. The <em>handler</em> parameter needs to be a SAX <tt class="xref py py-class docutils literal"><span class="pre">ContentHandler</span></tt> instance. If <em>error_handler</em> is given, it must be a SAX <tt class="xref py py-class docutils literal"><span class="pre">ErrorHandler</span></tt> instance; if omitted, <a class="reference internal" href="#xml.sax.SAXParseException" title="xml.sax.SAXParseException"><tt class="xref py py-exc docutils literal"><span class="pre">SAXParseException</span></tt></a> will be raised on all errors. There is no return value; all work must be done by the <em>handler</em> passed in.</p> </dd></dl> <dl class="function"> <dt id="xml.sax.parseString"> <tt class="descclassname">xml.sax.</tt><tt class="descname">parseString</tt><big>(</big><em>string</em>, <em>handler</em><span class="optional">[</span>, <em>error_handler</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#xml.sax.parseString" title="Permalink to this definition">¶</a></dt> <dd><p>Similar to <a class="reference internal" href="#xml.sax.parse" title="xml.sax.parse"><tt class="xref py py-func docutils literal"><span class="pre">parse()</span></tt></a>, but parses from a buffer <em>string</em> received as a parameter.</p> </dd></dl> <p>A typical SAX application uses three kinds of objects: readers, handlers and input sources. “Reader” in this context is another term for parser, i.e. some piece of code that reads the bytes or characters from the input source, and produces a sequence of events. The events then get distributed to the handler objects, i.e. the reader invokes a method on the handler. A SAX application must therefore obtain a reader object, create or open the input sources, create the handlers, and connect these objects all together. As the final step of preparation, the reader is called to parse the input. During parsing, methods on the handler objects are called based on structural and syntactic events from the input data.</p> <p>For these objects, only the interfaces are relevant; they are normally not instantiated by the application itself. Since Python does not have an explicit notion of interface, they are formally introduced as classes, but applications may use implementations which do not inherit from the provided classes. The <tt class="xref py py-class docutils literal"><span class="pre">InputSource</span></tt>, <tt class="xref py py-class docutils literal"><span class="pre">Locator</span></tt>, <tt class="xref py py-class docutils literal"><span class="pre">Attributes</span></tt>, <tt class="xref py py-class docutils literal"><span class="pre">AttributesNS</span></tt>, and <tt class="xref py py-class docutils literal"><span class="pre">XMLReader</span></tt> interfaces are defined in the module <a class="reference internal" href="xml.sax.reader.html#module-xml.sax.xmlreader" title="xml.sax.xmlreader: Interface which SAX-compliant XML parsers must implement."><tt class="xref py py-mod docutils literal"><span class="pre">xml.sax.xmlreader</span></tt></a>. The handler interfaces are defined in <a class="reference internal" href="xml.sax.handler.html#module-xml.sax.handler" title="xml.sax.handler: Base classes for SAX event handlers."><tt class="xref py py-mod docutils literal"><span class="pre">xml.sax.handler</span></tt></a>. For convenience, <tt class="xref py py-class docutils literal"><span class="pre">InputSource</span></tt> (which is often instantiated directly) and the handler classes are also available from <a class="reference internal" href="#module-xml.sax" title="xml.sax: Package containing SAX2 base classes and convenience functions."><tt class="xref py py-mod docutils literal"><span class="pre">xml.sax</span></tt></a>. These interfaces are described below.</p> <p>In addition to these classes, <a class="reference internal" href="#module-xml.sax" title="xml.sax: Package containing SAX2 base classes and convenience functions."><tt class="xref py py-mod docutils literal"><span class="pre">xml.sax</span></tt></a> provides the following exception classes.</p> <dl class="exception"> <dt id="xml.sax.SAXException"> <em class="property">exception </em><tt class="descclassname">xml.sax.</tt><tt class="descname">SAXException</tt><big>(</big><em>msg</em><span class="optional">[</span>, <em>exception</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#xml.sax.SAXException" title="Permalink to this definition">¶</a></dt> <dd><p>Encapsulate an XML error or warning. This class can contain basic error or warning information from either the XML parser or the application: it can be subclassed to provide additional functionality or to add localization. Note that although the handlers defined in the <tt class="xref py py-class docutils literal"><span class="pre">ErrorHandler</span></tt> interface receive instances of this exception, it is not required to actually raise the exception — it is also useful as a container for information.</p> <p>When instantiated, <em>msg</em> should be a human-readable description of the error. The optional <em>exception</em> parameter, if given, should be <tt class="docutils literal"><span class="pre">None</span></tt> or an exception that was caught by the parsing code and is being passed along as information.</p> <p>This is the base class for the other SAX exception classes.</p> </dd></dl> <dl class="exception"> <dt id="xml.sax.SAXParseException"> <em class="property">exception </em><tt class="descclassname">xml.sax.</tt><tt class="descname">SAXParseException</tt><big>(</big><em>msg</em>, <em>exception</em>, <em>locator</em><big>)</big><a class="headerlink" href="#xml.sax.SAXParseException" title="Permalink to this definition">¶</a></dt> <dd><p>Subclass of <a class="reference internal" href="#xml.sax.SAXException" title="xml.sax.SAXException"><tt class="xref py py-exc docutils literal"><span class="pre">SAXException</span></tt></a> raised on parse errors. Instances of this class are passed to the methods of the SAX <tt class="xref py py-class docutils literal"><span class="pre">ErrorHandler</span></tt> interface to provide information about the parse error. This class supports the SAX <tt class="xref py py-class docutils literal"><span class="pre">Locator</span></tt> interface as well as the <a class="reference internal" href="#xml.sax.SAXException" title="xml.sax.SAXException"><tt class="xref py py-class docutils literal"><span class="pre">SAXException</span></tt></a> interface.</p> </dd></dl> <dl class="exception"> <dt id="xml.sax.SAXNotRecognizedException"> <em class="property">exception </em><tt class="descclassname">xml.sax.</tt><tt class="descname">SAXNotRecognizedException</tt><big>(</big><em>msg</em><span class="optional">[</span>, <em>exception</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#xml.sax.SAXNotRecognizedException" title="Permalink to this definition">¶</a></dt> <dd><p>Subclass of <a class="reference internal" href="#xml.sax.SAXException" title="xml.sax.SAXException"><tt class="xref py py-exc docutils literal"><span class="pre">SAXException</span></tt></a> raised when a SAX <tt class="xref py py-class docutils literal"><span class="pre">XMLReader</span></tt> is confronted with an unrecognized feature or property. SAX applications and extensions may use this class for similar purposes.</p> </dd></dl> <dl class="exception"> <dt id="xml.sax.SAXNotSupportedException"> <em class="property">exception </em><tt class="descclassname">xml.sax.</tt><tt class="descname">SAXNotSupportedException</tt><big>(</big><em>msg</em><span class="optional">[</span>, <em>exception</em><span class="optional">]</span><big>)</big><a class="headerlink" href="#xml.sax.SAXNotSupportedException" title="Permalink to this definition">¶</a></dt> <dd><p>Subclass of <a class="reference internal" href="#xml.sax.SAXException" title="xml.sax.SAXException"><tt class="xref py py-exc docutils literal"><span class="pre">SAXException</span></tt></a> raised when a SAX <tt class="xref py py-class docutils literal"><span class="pre">XMLReader</span></tt> is asked to enable a feature that is not supported, or to set a property to a value that the implementation does not support. SAX applications and extensions may use this class for similar purposes.</p> </dd></dl> <div class="admonition-see-also admonition seealso"> <p class="first admonition-title">See also</p> <dl class="last docutils"> <dt><a class="reference external" href="http://www.saxproject.org/">SAX: The Simple API for XML</a></dt> <dd>This site is the focal point for the definition of the SAX API. It provides a Java implementation and online documentation. Links to implementations and historical information are also available.</dd> <dt>Module <a class="reference internal" href="xml.sax.handler.html#module-xml.sax.handler" title="xml.sax.handler: Base classes for SAX event handlers."><tt class="xref py py-mod docutils literal"><span class="pre">xml.sax.handler</span></tt></a></dt> <dd>Definitions of the interfaces for application-provided objects.</dd> <dt>Module <a class="reference internal" href="xml.sax.utils.html#module-xml.sax.saxutils" title="xml.sax.saxutils: Convenience functions and classes for use with SAX."><tt class="xref py py-mod docutils literal"><span class="pre">xml.sax.saxutils</span></tt></a></dt> <dd>Convenience functions for use in SAX applications.</dd> <dt>Module <a class="reference internal" href="xml.sax.reader.html#module-xml.sax.xmlreader" title="xml.sax.xmlreader: Interface which SAX-compliant XML parsers must implement."><tt class="xref py py-mod docutils literal"><span class="pre">xml.sax.xmlreader</span></tt></a></dt> <dd>Definitions of the interfaces for parser-provided objects.</dd> </dl> </div> <div class="section" id="saxexception-objects"> <span id="sax-exception-objects"></span><h2>19.11.1. SAXException Objects<a class="headerlink" href="#saxexception-objects" title="Permalink to this headline">¶</a></h2> <p>The <a class="reference internal" href="#xml.sax.SAXException" title="xml.sax.SAXException"><tt class="xref py py-class docutils literal"><span class="pre">SAXException</span></tt></a> exception class supports the following methods:</p> <dl class="method"> <dt id="xml.sax.SAXException.getMessage"> <tt class="descclassname">SAXException.</tt><tt class="descname">getMessage</tt><big>(</big><big>)</big><a class="headerlink" href="#xml.sax.SAXException.getMessage" title="Permalink to this definition">¶</a></dt> <dd><p>Return a human-readable message describing the error condition.</p> </dd></dl> <dl class="method"> <dt id="xml.sax.SAXException.getException"> <tt class="descclassname">SAXException.</tt><tt class="descname">getException</tt><big>(</big><big>)</big><a class="headerlink" href="#xml.sax.SAXException.getException" title="Permalink to this definition">¶</a></dt> <dd><p>Return an encapsulated exception object, or <tt class="docutils literal"><span class="pre">None</span></tt>.</p> </dd></dl> </div> </div> </div> </div> </div> <div class="sphinxsidebar"> <div class="sphinxsidebarwrapper"> <h3><a href="../contents.html">Table Of Contents</a></h3> <ul> <li><a class="reference internal" href="#">19.11. <tt class="docutils literal"><span class="pre">xml.sax</span></tt> — Support for SAX2 parsers</a><ul> <li><a class="reference internal" href="#saxexception-objects">19.11.1. SAXException Objects</a></li> </ul> </li> </ul> <h4>Previous topic</h4> <p class="topless"><a href="xml.dom.pulldom.html" title="previous chapter">19.10. <tt class="docutils literal"><span class="pre">xml.dom.pulldom</span></tt> — Support for building partial DOM trees</a></p> <h4>Next topic</h4> <p class="topless"><a href="xml.sax.handler.html" title="next chapter">19.12. <tt class="docutils literal"><span class="pre">xml.sax.handler</span></tt> — Base classes for SAX handlers</a></p> <h3>This Page</h3> <ul class="this-page-menu"> <li><a href="../bugs.html">Report a Bug</a></li> <li><a href="../_sources/library/xml.sax.txt" rel="nofollow">Show Source</a></li> </ul> <div id="searchbox" style="display: none"> <h3>Quick search</h3> <form class="search" action="../search.html" method="get"> <input 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> <p class="searchtip" style="font-size: 90%"> Enter search terms or a module, class or function name. </p> </div> <script type="text/javascript">$('#searchbox').show(0);</script> </div> </div> <div class="clearer"></div> </div> <div class="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="xml.sax.handler.html" title="19.12. xml.sax.handler — Base classes for SAX handlers" >next</a> |</li> <li class="right" > <a href="xml.dom.pulldom.html" title="19.10. xml.dom.pulldom — Support for building partial DOM trees" >previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="http://www.python.org/">Python</a> »</li> <li> <a href="../index.html">Python 2.7.5 documentation</a> » </li> <li><a href="index.html" >The Python Standard Library</a> »</li> <li><a href="markup.html" >19. 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