<?xml version="1.0" encoding="ascii"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <title>genshi.core.Stream</title> <link rel="stylesheet" href="epydoc.css" type="text/css" /> <script type="text/javascript" src="epydoc.js"></script> </head> <body bgcolor="white" text="black" link="blue" vlink="#204080" alink="#204080"> <!-- ==================== NAVIGATION BAR ==================== --> <table class="navbar" border="0" width="100%" cellpadding="0" bgcolor="#a0c0ff" cellspacing="0"> <tr valign="middle"> <!-- Home link --> <th> <a href="genshi-module.html">Home</a> </th> <!-- Tree link --> <th> <a href="module-tree.html">Trees</a> </th> <!-- Index link --> <th> <a href="identifier-index.html">Indices</a> </th> <!-- Help link --> <th> <a href="help.html">Help</a> </th> <!-- Project homepage --> <th class="navbar" align="right" width="100%"> <table border="0" cellpadding="0" cellspacing="0"> <tr><th class="navbar" align="center" ><a class="navbar" target="_top" href="../index.html">Documentation Index</a></th> </tr></table></th> </tr> </table> <table width="100%" cellpadding="0" cellspacing="0"> <tr valign="top"> <td width="100%"> <span class="breadcrumbs"> <a href="genshi-module.html">Package genshi</a> :: <a href="genshi.core-module.html">Module core</a> :: Class Stream </span> </td> <td> <table cellpadding="0" cellspacing="0"> <!-- hide/show private --> </table> </td> </tr> </table> <!-- ==================== CLASS DESCRIPTION ==================== --> <h1 class="epydoc">Class Stream</h1><p class="nomargin-top"></p> <pre class="base-tree"> object --+ | <strong class="uidshort">Stream</strong> </pre> <dl><dt>Known Subclasses:</dt> <dd> <ul class="subclass-list"> <li><a href="genshi.filters.transform.StreamBuffer-class.html">filters.transform.StreamBuffer</a></li> </ul> </dd></dl> <hr /> <p>Represents a stream of markup events.</p> <p>This class is basically an iterator over the events.</p> <p>Stream events are tuples of the form:</p> <pre class="rst-literal-block"> (kind, data, position) </pre> <p>where <tt class="rst-docutils literal"><span class="pre">kind</span></tt> is the event kind (such as <a href="genshi.core.Stream-class.html#START" class="link">START</a>, <a href="genshi.core.Stream-class.html#END" class="link">END</a>, <a href="genshi.core.Stream-class.html#TEXT" class="link">TEXT</a>, etc), <tt class="rst-docutils literal"><span class="pre">data</span></tt> depends on the kind of event, and <tt class="rst-docutils literal"><span class="pre">position</span></tt> is a <tt class="rst-docutils literal"><span class="pre">(filename,</span> <span class="pre">line,</span> <span class="pre">offset)</span></tt> tuple that contains the location of the original element or text in the input. If the original location is unknown, <tt class="rst-docutils literal"><span class="pre">position</span></tt> is <tt class="rst-docutils literal"><span class="pre">(None,</span> <span class="pre">-1,</span> <span class="pre">-1)</span></tt>.</p> <p>Also provided are ways to serialize the stream to text. The <a href="genshi.core.Stream-class.html#serialize" class="link">serialize()</a> method will return an iterator over generated strings, while <a href="genshi.core.Stream-class.html#render" class="link">render()</a> returns the complete generated text at once. Both accept various parameters that impact the way the stream is serialized.</p> <!-- ==================== INSTANCE METHODS ==================== --> <a name="section-InstanceMethods"></a> <table class="summary" border="1" cellpadding="3" cellspacing="0" width="100%" bgcolor="white"> <tr bgcolor="#70b0f0" class="table-header"> <td align="left" colspan="2" class="table-header"> <span class="table-header">Instance Methods</span></td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr> <td><span class="summary-sig"><a href="genshi.core.Stream-class.html#__init__" class="summary-sig-name">__init__</a>(<span class="summary-sig-arg">self</span>, <span class="summary-sig-arg">events</span>, <span class="summary-sig-arg">serializer</span>=<span class="summary-sig-default">None</span>)</span><br /> Initialize the stream with a sequence of markup events.</td> <td align="right" valign="top"> </td> </tr> </table> </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr> <td><span class="summary-sig"><a name="__iter__"></a><span class="summary-sig-name">__iter__</span>(<span class="summary-sig-arg">self</span>)</span></td> <td align="right" valign="top"> </td> </tr> </table> </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"><a href="genshi.core.Stream-class.html" class="link">Stream</a></span> </td><td class="summary"> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr> <td><span class="summary-sig"><a href="genshi.core.Stream-class.html#__or__" class="summary-sig-name">__or__</a>(<span class="summary-sig-arg">self</span>, <span class="summary-sig-arg">function</span>)</span><br /> Override the "bitwise or" operator to apply filters or serializers to the stream, providing a syntax similar to pipes on Unix shells.</td> <td align="right" valign="top"> </td> </tr> </table> </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"><a href="genshi.core.Stream-class.html" class="link">Stream</a></span> </td><td class="summary"> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr> <td><span class="summary-sig"><a href="genshi.core.Stream-class.html#filter" class="summary-sig-name">filter</a>(<span class="summary-sig-arg">self</span>, <span class="summary-sig-arg">*filters</span>)</span><br /> Apply filters to the stream.</td> <td align="right" valign="top"> </td> </tr> </table> </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"><code class="link">basestring</code></span> </td><td class="summary"> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr> <td><span class="summary-sig"><a href="genshi.core.Stream-class.html#render" class="summary-sig-name">render</a>(<span class="summary-sig-arg">self</span>, <span class="summary-sig-arg">method</span>=<span class="summary-sig-default">None</span>, <span class="summary-sig-arg">encoding</span>=<span class="summary-sig-default"><code class="variable-quote">'</code><code class="variable-string">utf-8</code><code class="variable-quote">'</code></span>, <span class="summary-sig-arg">out</span>=<span class="summary-sig-default">None</span>, <span class="summary-sig-arg">**kwargs</span>)</span><br /> Return a string representation of the stream.</td> <td align="right" valign="top"> </td> </tr> </table> </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"><a href="genshi.core.Stream-class.html" class="link">Stream</a></span> </td><td class="summary"> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr> <td><span class="summary-sig"><a href="genshi.core.Stream-class.html#select" class="summary-sig-name">select</a>(<span class="summary-sig-arg">self</span>, <span class="summary-sig-arg">path</span>, <span class="summary-sig-arg">namespaces</span>=<span class="summary-sig-default">None</span>, <span class="summary-sig-arg">variables</span>=<span class="summary-sig-default">None</span>)</span><br /> Return a new stream that contains the events matching the given XPath expression.</td> <td align="right" valign="top"> </td> </tr> </table> </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"><tt class="rst-docutils literal"><span class="pre">iterator</span></tt></span> </td><td class="summary"> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr> <td><span class="summary-sig"><a href="genshi.core.Stream-class.html#serialize" class="summary-sig-name">serialize</a>(<span class="summary-sig-arg">self</span>, <span class="summary-sig-arg">method</span>=<span class="summary-sig-default"><code class="variable-quote">'</code><code class="variable-string">xml</code><code class="variable-quote">'</code></span>, <span class="summary-sig-arg">**kwargs</span>)</span><br /> Generate strings corresponding to a specific serialization of the stream.</td> <td align="right" valign="top"> </td> </tr> </table> </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr> <td><span class="summary-sig"><a href="genshi.core.Stream-class.html#__str__" class="summary-sig-name">__str__</a>(<span class="summary-sig-arg">self</span>)</span><br /> str(x)</td> <td align="right" valign="top"> </td> </tr> </table> </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr> <td><span class="summary-sig"><a name="__unicode__"></a><span class="summary-sig-name">__unicode__</span>(<span class="summary-sig-arg">self</span>)</span></td> <td align="right" valign="top"> </td> </tr> </table> </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr> <td><span class="summary-sig"><a name="__html__"></a><span class="summary-sig-name">__html__</span>(<span class="summary-sig-arg">self</span>)</span></td> <td align="right" valign="top"> </td> </tr> </table> </td> </tr> <tr> <td colspan="2" class="summary"> <p class="indent-wrapped-lines"><b>Inherited from <code>object</code></b>: <code>__delattr__</code>, <code>__getattribute__</code>, <code>__hash__</code>, <code>__new__</code>, <code>__reduce__</code>, <code>__reduce_ex__</code>, <code>__repr__</code>, <code>__setattr__</code> </p> </td> </tr> </table> <!-- ==================== CLASS VARIABLES ==================== --> <a name="section-ClassVariables"></a> <table class="summary" border="1" cellpadding="3" cellspacing="0" width="100%" bgcolor="white"> <tr bgcolor="#70b0f0" class="table-header"> <td align="left" colspan="2" class="table-header"> <span class="table-header">Class Variables</span></td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <a name="START"></a><span class="summary-name">START</span> = <code title="'START'">'START'</code><br /> a start tag </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <a name="END"></a><span class="summary-name">END</span> = <code title="'END'">'END'</code><br /> an end tag </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <a name="TEXT"></a><span class="summary-name">TEXT</span> = <code title="'TEXT'">'TEXT'</code><br /> literal text </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <a name="XML_DECL"></a><span class="summary-name">XML_DECL</span> = <code title="'XML_DECL'">'XML_DECL'</code><br /> XML declaration </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <a name="DOCTYPE"></a><span class="summary-name">DOCTYPE</span> = <code title="'DOCTYPE'">'DOCTYPE'</code><br /> doctype declaration </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <a name="START_NS"></a><span class="summary-name">START_NS</span> = <code title="'START_NS'">'START_NS'</code><br /> start namespace mapping </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <a name="END_NS"></a><span class="summary-name">END_NS</span> = <code title="'END_NS'">'END_NS'</code><br /> end namespace mapping </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <a name="START_CDATA"></a><span class="summary-name">START_CDATA</span> = <code title="'START_CDATA'">'START_CDATA'</code><br /> start CDATA section </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <a name="END_CDATA"></a><span class="summary-name">END_CDATA</span> = <code title="'END_CDATA'">'END_CDATA'</code><br /> end CDATA section </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <a name="PI"></a><span class="summary-name">PI</span> = <code title="'PI'">'PI'</code><br /> processing instruction </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <a name="COMMENT"></a><span class="summary-name">COMMENT</span> = <code title="'COMMENT'">'COMMENT'</code><br /> comment </td> </tr> </table> <!-- ==================== INSTANCE VARIABLES ==================== --> <a name="section-InstanceVariables"></a> <table class="summary" border="1" cellpadding="3" cellspacing="0" width="100%" bgcolor="white"> <tr bgcolor="#70b0f0" class="table-header"> <td align="left" colspan="2" class="table-header"> <span class="table-header">Instance Variables</span></td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <a name="events"></a><span class="summary-name">events</span><br /> The underlying iterable producing the events </td> </tr> <tr> <td width="15%" align="right" valign="top" class="summary"> <span class="summary-type"> </span> </td><td class="summary"> <a name="serializer"></a><span class="summary-name">serializer</span><br /> The default serializion method </td> </tr> </table> <!-- ==================== PROPERTIES ==================== --> <a name="section-Properties"></a> <table class="summary" border="1" cellpadding="3" cellspacing="0" width="100%" bgcolor="white"> <tr bgcolor="#70b0f0" class="table-header"> <td align="left" colspan="2" class="table-header"> <span class="table-header">Properties</span></td> </tr> <tr> <td colspan="2" class="summary"> <p class="indent-wrapped-lines"><b>Inherited from <code>object</code></b>: <code>__class__</code> </p> </td> </tr> </table> <!-- ==================== METHOD DETAILS ==================== --> <a name="section-MethodDetails"></a> <table class="details" border="1" cellpadding="3" cellspacing="0" width="100%" bgcolor="white"> <tr bgcolor="#70b0f0" class="table-header"> <td align="left" colspan="2" class="table-header"> <span class="table-header">Method Details</span></td> </tr> </table> <a name="__init__"></a> <div> <table class="details" border="1" cellpadding="3" cellspacing="0" width="100%" bgcolor="white"> <tr><td> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr valign="top"><td> <h3 class="epydoc"><span class="sig"><span class="sig-name">__init__</span>(<span class="sig-arg">self</span>, <span class="sig-arg">events</span>, <span class="sig-arg">serializer</span>=<span class="sig-default">None</span>)</span> <br /><em class="fname">(Constructor)</em> </h3> </td><td align="right" valign="top" > </td> </tr></table> Initialize the stream with a sequence of markup events. <dl class="fields"> <dt>Parameters:</dt> <dd><ul class="nomargin-top"> <li><strong class="pname"><code>events</code></strong> - a sequence or iterable providing the events</li> <li><strong class="pname"><code>serializer</code></strong> - the default serialization method to use for this stream</li> </ul></dd> <dt>Overrides: object.__init__ </dt> </dl> <div class="fields"> <p><strong>Note:</strong> Changed in 0.5: added the <a href="genshi.core.Stream-class.html#serializer" class="link">serializer</a> argument </p> </div></td></tr></table> </div> <a name="__or__"></a> <div> <table class="details" border="1" cellpadding="3" cellspacing="0" width="100%" bgcolor="white"> <tr><td> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr valign="top"><td> <h3 class="epydoc"><span class="sig"><span class="sig-name">__or__</span>(<span class="sig-arg">self</span>, <span class="sig-arg">function</span>)</span> <br /><em class="fname">(Or operator)</em> </h3> </td><td align="right" valign="top" > </td> </tr></table> <p>Override the "bitwise or" operator to apply filters or serializers to the stream, providing a syntax similar to pipes on Unix shells.</p> <p>Assume the following stream produced by the <a href="genshi.input-module.html#HTML" class="link">HTML</a> function:</p> <pre class="py-doctest"> <span class="py-prompt">>>> </span><span class="py-keyword">from</span> genshi.input <span class="py-keyword">import</span> HTML <span class="py-prompt">>>> </span>html = HTML(<span class="py-string">'''<p onclick="alert('Whoa')">Hello, world!</p>'''</span>) <span class="py-prompt">>>> </span><span class="py-keyword">print</span> html <span class="py-output"><p onclick="alert('Whoa')">Hello, world!</p></span></pre> <p>A filter such as the HTML sanitizer can be applied to that stream using the pipe notation as follows:</p> <pre class="py-doctest"> <span class="py-prompt">>>> </span><span class="py-keyword">from</span> genshi.filters <span class="py-keyword">import</span> HTMLSanitizer <span class="py-prompt">>>> </span>sanitizer = HTMLSanitizer() <span class="py-prompt">>>> </span><span class="py-keyword">print</span> html | sanitizer <span class="py-output"><p>Hello, world!</p></span></pre> <p>Filters can be any function that accepts and produces a stream (where a stream is anything that iterates over events):</p> <pre class="py-doctest"> <span class="py-prompt">>>> </span><span class="py-keyword">def</span> <span class="py-defname">uppercase</span>(stream): <span class="py-more">... </span> <span class="py-keyword">for</span> kind, data, pos <span class="py-keyword">in</span> stream: <span class="py-more">... </span> <span class="py-keyword">if</span> kind <span class="py-keyword">is</span> TEXT: <span class="py-more">... </span> data = data.upper() <span class="py-more">... </span> yield kind, data, pos <span class="py-prompt">>>> </span><span class="py-keyword">print</span> html | sanitizer | uppercase <span class="py-output"><p>HELLO, WORLD!</p></span></pre> <p>Serializers can also be used with this notation:</p> <pre class="py-doctest"> <span class="py-prompt">>>> </span><span class="py-keyword">from</span> genshi.output <span class="py-keyword">import</span> TextSerializer <span class="py-prompt">>>> </span>output = TextSerializer() <span class="py-prompt">>>> </span><span class="py-keyword">print</span> html | sanitizer | uppercase | output <span class="py-output">HELLO, WORLD!</span></pre> <p>Commonly, serializers should be used at the end of the "pipeline"; using them somewhere in the middle may produce unexpected results.</p> <dl class="fields"> <dt>Parameters:</dt> <dd><ul class="nomargin-top"> <li><strong class="pname"><code>function</code></strong> - the callable object that should be applied as a filter</li> </ul></dd> <dt>Returns: <a href="genshi.core.Stream-class.html" class="link">Stream</a></dt> <dd>the filtered stream</dd> </dl> </td></tr></table> </div> <a name="filter"></a> <div> <table class="details" border="1" cellpadding="3" cellspacing="0" width="100%" bgcolor="white"> <tr><td> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr valign="top"><td> <h3 class="epydoc"><span class="sig"><span class="sig-name">filter</span>(<span class="sig-arg">self</span>, <span class="sig-arg">*filters</span>)</span> </h3> </td><td align="right" valign="top" > </td> </tr></table> <p>Apply filters to the stream.</p> <p>This method returns a new stream with the given filters applied. The filters must be callables that accept the stream object as parameter, and return the filtered stream.</p> <p>The call:</p> <pre class="rst-literal-block"> stream.filter(filter1, filter2) </pre> <p>is equivalent to:</p> <pre class="rst-literal-block"> stream | filter1 | filter2 </pre> <dl class="fields"> <dt>Parameters:</dt> <dd><ul class="nomargin-top"> <li><strong class="pname"><code>filters</code></strong> - one or more callable objects that should be applied as filters</li> </ul></dd> <dt>Returns: <a href="genshi.core.Stream-class.html" class="link">Stream</a></dt> <dd>the filtered stream</dd> </dl> </td></tr></table> </div> <a name="render"></a> <div> <table class="details" border="1" cellpadding="3" cellspacing="0" width="100%" bgcolor="white"> <tr><td> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr valign="top"><td> <h3 class="epydoc"><span class="sig"><span class="sig-name">render</span>(<span class="sig-arg">self</span>, <span class="sig-arg">method</span>=<span class="sig-default">None</span>, <span class="sig-arg">encoding</span>=<span class="sig-default"><code class="variable-quote">'</code><code class="variable-string">utf-8</code><code class="variable-quote">'</code></span>, <span class="sig-arg">out</span>=<span class="sig-default">None</span>, <span class="sig-arg">**kwargs</span>)</span> </h3> </td><td align="right" valign="top" > </td> </tr></table> <p>Return a string representation of the stream.</p> <p>Any additional keyword arguments are passed to the serializer, and thus depend on the <code class="link">method</code> parameter value.</p> <dl class="fields"> <dt>Parameters:</dt> <dd><ul class="nomargin-top"> <li><strong class="pname"><code>method</code></strong> - determines how the stream is serialized; can be either "xml", "xhtml", "html", "text", or a custom serializer class; if <code class="link">None</code>, the default serialization method of the stream is used</li> <li><strong class="pname"><code>encoding</code></strong> - how the output string should be encoded; if set to <code class="link">None</code>, this method returns a <code class="link">unicode</code> object</li> <li><strong class="pname"><code>out</code></strong> - a file-like object that the output should be written to instead of being returned as one big string; note that if this is a file or socket (or similar), the <code class="link">encoding</code> must not be <code class="link">None</code> (that is, the output must be encoded)</li> </ul></dd> <dt>Returns: <code class="link">basestring</code></dt> <dd>a <code class="link">str</code> or <code class="link">unicode</code> object (depending on the <code class="link">encoding</code> parameter), or <code class="link">None</code> if the <code class="link">out</code> parameter is provided</dd> </dl> <div class="fields"> <p><strong>See Also:</strong> XMLSerializer, XHTMLSerializer, HTMLSerializer, TextSerializer </p> <p><strong>Note:</strong> Changed in 0.5: added the <code class="link">out</code> parameter </p> </div></td></tr></table> </div> <a name="select"></a> <div> <table class="details" border="1" cellpadding="3" cellspacing="0" width="100%" bgcolor="white"> <tr><td> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr valign="top"><td> <h3 class="epydoc"><span class="sig"><span class="sig-name">select</span>(<span class="sig-arg">self</span>, <span class="sig-arg">path</span>, <span class="sig-arg">namespaces</span>=<span class="sig-default">None</span>, <span class="sig-arg">variables</span>=<span class="sig-default">None</span>)</span> </h3> </td><td align="right" valign="top" > </td> </tr></table> <p>Return a new stream that contains the events matching the given XPath expression.</p> <pre class="py-doctest"> <span class="py-prompt">>>> </span><span class="py-keyword">from</span> genshi <span class="py-keyword">import</span> HTML <span class="py-prompt">>>> </span>stream = HTML(<span class="py-string">'<doc><elem>foo</elem><elem>bar</elem></doc>'</span>) <span class="py-prompt">>>> </span><span class="py-keyword">print</span> stream.select(<span class="py-string">'elem'</span>) <span class="py-output"><elem>foo</elem><elem>bar</elem></span> <span class="py-output"></span><span class="py-prompt">>>> </span><span class="py-keyword">print</span> stream.select(<span class="py-string">'elem/text()'</span>) <span class="py-output">foobar</span></pre> <p>Note that the outermost element of the stream becomes the <em>context node</em> for the XPath test. That means that the expression "doc" would not match anything in the example above, because it only tests against child elements of the outermost element:</p> <pre class="py-doctest"> <span class="py-prompt">>>> </span><span class="py-keyword">print</span> stream.select(<span class="py-string">'doc'</span>) <span class="py-output"><BLANKLINE></span></pre> <p>You can use the "." expression to match the context node itself (although that usually makes little sense):</p> <pre class="py-doctest"> <span class="py-prompt">>>> </span><span class="py-keyword">print</span> stream.select(<span class="py-string">'.'</span>) <span class="py-output"><doc><elem>foo</elem><elem>bar</elem></doc></span></pre> <dl class="fields"> <dt>Parameters:</dt> <dd><ul class="nomargin-top"> <li><strong class="pname"><code>path</code></strong> - a string containing the XPath expression</li> <li><strong class="pname"><code>namespaces</code></strong> - mapping of namespace prefixes used in the path</li> <li><strong class="pname"><code>variables</code></strong> - mapping of variable names to values</li> </ul></dd> <dt>Returns: <a href="genshi.core.Stream-class.html" class="link">Stream</a></dt> <dd>the selected substream</dd> <dt>Raises:</dt> <dd><ul class="nomargin-top"> <li><code><strong class='fraise'><a href="genshi.path.PathSyntaxError-class.html">PathSyntaxError</a></strong></code> - if the given path expression is invalid or not supported</li> </ul></dd> </dl> </td></tr></table> </div> <a name="serialize"></a> <div> <table class="details" border="1" cellpadding="3" cellspacing="0" width="100%" bgcolor="white"> <tr><td> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr valign="top"><td> <h3 class="epydoc"><span class="sig"><span class="sig-name">serialize</span>(<span class="sig-arg">self</span>, <span class="sig-arg">method</span>=<span class="sig-default"><code class="variable-quote">'</code><code class="variable-string">xml</code><code class="variable-quote">'</code></span>, <span class="sig-arg">**kwargs</span>)</span> </h3> </td><td align="right" valign="top" > </td> </tr></table> <p>Generate strings corresponding to a specific serialization of the stream.</p> <p>Unlike the <a href="genshi.core.Stream-class.html#render" class="link">render()</a> method, this method is a generator that returns the serialized output incrementally, as opposed to returning a single string.</p> <p>Any additional keyword arguments are passed to the serializer, and thus depend on the <code class="link">method</code> parameter value.</p> <dl class="fields"> <dt>Parameters:</dt> <dd><ul class="nomargin-top"> <li><strong class="pname"><code>method</code></strong> - determines how the stream is serialized; can be either "xml", "xhtml", "html", "text", or a custom serializer class; if <code class="link">None</code>, the default serialization method of the stream is used</li> </ul></dd> <dt>Returns: <tt class="rst-rst-docutils literal rst-docutils literal"><span class="pre">iterator</span></tt></dt> <dd>an iterator over the serialization results (<a href="genshi.core.Markup-class.html" class="link">Markup</a> or <code class="link">unicode</code> objects, depending on the serialization method)</dd> </dl> <div class="fields"> <p><strong>See Also:</strong> XMLSerializer, XHTMLSerializer, HTMLSerializer, TextSerializer </p> </div></td></tr></table> </div> <a name="__str__"></a> <div> <table class="details" border="1" cellpadding="3" cellspacing="0" width="100%" bgcolor="white"> <tr><td> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr valign="top"><td> <h3 class="epydoc"><span class="sig"><span class="sig-name">__str__</span>(<span class="sig-arg">self</span>)</span> <br /><em class="fname">(Informal representation operator)</em> </h3> </td><td align="right" valign="top" > </td> </tr></table> str(x) <dl class="fields"> <dt>Overrides: object.__str__ <dd><em class="note">(inherited documentation)</em></dd> </dt> </dl> </td></tr></table> </div> <br /> <!-- ==================== NAVIGATION BAR ==================== --> <table class="navbar" border="0" width="100%" cellpadding="0" bgcolor="#a0c0ff" cellspacing="0"> <tr valign="middle"> <!-- Home link --> <th> <a href="genshi-module.html">Home</a> </th> <!-- Tree link --> <th> <a href="module-tree.html">Trees</a> </th> <!-- Index link --> <th> <a href="identifier-index.html">Indices</a> </th> <!-- Help link --> <th> <a href="help.html">Help</a> </th> <!-- Project homepage --> <th class="navbar" align="right" width="100%"> <table border="0" cellpadding="0" cellspacing="0"> <tr><th class="navbar" align="center" ><a class="navbar" target="_top" href="../index.html">Documentation Index</a></th> </tr></table></th> </tr> </table> <table border="0" cellpadding="0" cellspacing="0" width="100%%"> <tr> <td align="left" class="footer"> Generated by Epydoc 3.0.1 on Wed Jul 9 18:16:20 2008 </td> <td align="right" class="footer"> <a target="mainFrame" href="http://epydoc.sourceforge.net" >http://epydoc.sourceforge.net</a> </td> </tr> </table> <script type="text/javascript"> <!-- // Private objects are initially displayed (because if // javascript is turned off then we want them to be // visible); 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