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class="menu item"><a href="lxml-source-howto.html#where-to-start">Where to start?</a></li><li class="menu item"><a href="lxml-source-howto.html#lxml-etree">lxml.etree</a></li><li class="menu item"><a href="lxml-source-howto.html#python-modules">Python modules</a></li><li class="menu item"><a href="lxml-source-howto.html#lxml-objectify">lxml.objectify</a></li><li class="menu item"><a href="lxml-source-howto.html#lxml-html">lxml.html</a></li></ul></li></ul><ul class="menu foreign" id="changes 4 2 3-menu"><li class="menu title"><a href="changes-4.2.3.html">Release Changelog</a></li></ul><ul class="menu foreign" id="credits-menu"><li class="menu title"><a href="credits.html">Credits</a><ul class="submenu"><li class="menu item"><a href="credits.html#main-contributors">Main contributors</a></li><li class="menu item"><a href="credits.html#special-thanks-goes-to">Special thanks goes to:</a></li></ul></li></ul></li><li><a href="/sitemap.html">Sitemap</a></li></ul></div></div><h1 class="title">html5lib Parser</h1>
<p><a class="reference external" href="http://code.google.com/p/html5lib/">html5lib</a> is a Python package that implements the HTML5 parsing algorithm
which is heavily influenced by current browsers and based on the <a class="reference external" href="http://www.whatwg.org/specs/web-apps/current-work/">WHATWG
HTML5 specification</a>.</p>
<p>lxml can benefit from the parsing capabilities of <cite>html5lib</cite> through
the <tt class="docutils literal">lxml.html.html5parser</tt> module. It provides a similar interface
to the <tt class="docutils literal">lxml.html</tt> module by providing <tt class="docutils literal">fromstring()</tt>,
<tt class="docutils literal">parse()</tt>, <tt class="docutils literal">document_fromstring()</tt>, <tt class="docutils literal">fragment_fromstring()</tt> and
<tt class="docutils literal">fragments_fromstring()</tt> that work like the regular html parsing
functions.</p>
<div class="section" id="differences-to-regular-html-parsing">
<h1>Differences to regular HTML parsing</h1>
<p>There are a few differences in the returned tree to the regular HTML
parsing functions from <tt class="docutils literal">lxml.html</tt>. html5lib normalizes some elements
and element structures to a common format. For example even if a tables
does not have a <cite>tbody</cite> html5lib will inject one automatically:</p>
<div class="syntax"><pre><span class="gp">>>> </span><span class="kn">from</span> <span class="nn">lxml.html</span> <span class="kn">import</span> <span class="n">tostring</span><span class="p">,</span> <span class="n">html5parser</span>
<span class="gp">>>> </span><span class="n">tostring</span><span class="p">(</span><span class="n">html5parser</span><span class="o">.</span><span class="n">fromstring</span><span class="p">(</span><span class="s2">"<table><td>foo"</span><span class="p">))</span>
<span class="go">'<table><tbody><tr><td>foo</td></tr></tbody></table>'</span>
</pre></div>
<p>Also the parameters the functions accept are different.</p>
</div>
<div class="section" id="function-reference">
<h1>Function Reference</h1>
<dl class="docutils">
<dt><tt class="docutils literal">parse(filename_url_or_file)</tt>:</dt>
<dd>Parses the named file or url, or if the object has a <tt class="docutils literal">.read()</tt>
method, parses from that.</dd>
<dt><tt class="docutils literal">document_fromstring(html, guess_charset=True)</tt>:</dt>
<dd><p class="first">Parses a document from the given string. This always creates a
correct HTML document, which means the parent node is <tt class="docutils literal"><html></tt>,
and there is a body and possibly a head.</p>
<p class="last">If a bytestring is passed and <tt class="docutils literal">guess_charset</tt> is true the chardet
library (if installed) will guess the charset if ambiguities exist.</p>
</dd>
<dt><tt class="docutils literal">fragment_fromstring(string, create_parent=False, guess_charset=False)</tt>:</dt>
<dd><p class="first">Returns an HTML fragment from a string. The fragment must contain
just a single element, unless <tt class="docutils literal">create_parent</tt> is given;
e.g., <tt class="docutils literal">fragment_fromstring(string, <span class="pre">create_parent='div')</span></tt> will
wrap the element in a <tt class="docutils literal"><div></tt>. If <tt class="docutils literal">create_parent</tt> is true the
default parent tag (div) is used.</p>
<p class="last">If a bytestring is passed and <tt class="docutils literal">guess_charset</tt> is true the chardet
library (if installed) will guess the charset if ambiguities exist.</p>
</dd>
<dt><tt class="docutils literal">fragments_fromstring(string, no_leading_text=False, parser=None)</tt>:</dt>
<dd><p class="first">Returns a list of the elements found in the fragment. The first item in
the list may be a string. If <tt class="docutils literal">no_leading_text</tt> is true, then it will
be an error if there is leading text, and it will always be a list of
only elements.</p>
<p class="last">If a bytestring is passed and <tt class="docutils literal">guess_charset</tt> is true the chardet
library (if installed) will guess the charset if ambiguities exist.</p>
</dd>
<dt><tt class="docutils literal">fromstring(string)</tt>:</dt>
<dd>Returns <tt class="docutils literal">document_fromstring</tt> or <tt class="docutils literal">fragment_fromstring</tt>, based
on whether the string looks like a full document, or just a
fragment.</dd>
</dl>
<p>Additionally all parsing functions accept an <tt class="docutils literal">parser</tt> keyword argument
that can be set to a custom parser instance. To create custom parsers
you can subclass the <tt class="docutils literal">HTMLParser</tt> and <tt class="docutils literal">XHTMLParser</tt> from the same
module. Note that these are the parser classes provided by html5lib.</p>
</div>
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