<!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="Content-Type" content="text/html; charset=utf-8" />
<title>formats module — Whoosh 2.5.7 documentation</title>
<link rel="stylesheet" href="../_static/default.css" type="text/css" />
<link rel="stylesheet" href="../_static/pygments.css" type="text/css" />
<script type="text/javascript">
var DOCUMENTATION_OPTIONS = {
URL_ROOT: '../',
VERSION: '2.5.7',
COLLAPSE_INDEX: false,
FILE_SUFFIX: '.html',
HAS_SOURCE: true
};
</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>
<link rel="top" title="Whoosh 2.5.7 documentation" href="../index.html" />
<link rel="up" title="Whoosh API" href="api.html" />
<link rel="next" title="highlight module" href="highlight.html" />
<link rel="prev" title="filedb.structfile module" href="filedb/structfile.html" />
</head>
<body>
<div class="related">
<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="highlight.html" title="highlight module"
accesskey="N">next</a> |</li>
<li class="right" >
<a href="filedb/structfile.html" title="filedb.structfile module"
accesskey="P">previous</a> |</li>
<li><a href="../index.html">Whoosh 2.5.7 documentation</a> »</li>
<li><a href="api.html" accesskey="U">Whoosh API</a> »</li>
</ul>
</div>
<div class="document">
<div class="documentwrapper">
<div class="bodywrapper">
<div class="body">
<div class="section" id="module-whoosh.formats">
<span id="formats-module"></span><h1><tt class="docutils literal"><span class="pre">formats</span></tt> module<a class="headerlink" href="#module-whoosh.formats" title="Permalink to this headline">¶</a></h1>
<p>The classes in this module encode and decode posting information for a field.
The field format essentially determines what information is stored about each
occurance of a term.</p>
<div class="section" id="base-class">
<h2>Base class<a class="headerlink" href="#base-class" title="Permalink to this headline">¶</a></h2>
<dl class="class">
<dt id="whoosh.formats.Format">
<em class="property">class </em><tt class="descclassname">whoosh.formats.</tt><tt class="descname">Format</tt><big>(</big><em>field_boost=1.0</em>, <em>**options</em><big>)</big><a class="headerlink" href="#whoosh.formats.Format" title="Permalink to this definition">¶</a></dt>
<dd><p>Abstract base class representing a storage format for a field or vector.
Format objects are responsible for writing and reading the low-level
representation of a field. It controls what kind/level of information to
store about the indexed fields.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>field_boost</strong> – A constant boost factor to scale to the score
of all queries matching terms in this field.</td>
</tr>
</tbody>
</table>
<dl class="method">
<dt id="whoosh.formats.Format.decode_as">
<tt class="descname">decode_as</tt><big>(</big><em>astype</em>, <em>valuestring</em><big>)</big><a class="headerlink" href="#whoosh.formats.Format.decode_as" title="Permalink to this definition">¶</a></dt>
<dd><p>Interprets the encoded value string as ‘astype’, where ‘astype’ is
for example “frequency” or “positions”. This object must have a
corresponding decode_<astype>() method.</p>
</dd></dl>
<dl class="method">
<dt id="whoosh.formats.Format.decoder">
<tt class="descname">decoder</tt><big>(</big><em>name</em><big>)</big><a class="headerlink" href="#whoosh.formats.Format.decoder" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the bound method for interpreting value as ‘name’,
where ‘name’ is for example “frequency” or “positions”. This
object must have a corresponding Format.decode_<name>() method.</p>
</dd></dl>
<dl class="method">
<dt id="whoosh.formats.Format.supports">
<tt class="descname">supports</tt><big>(</big><em>name</em><big>)</big><a class="headerlink" href="#whoosh.formats.Format.supports" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns True if this format supports interpreting its posting
value as ‘name’ (e.g. “frequency” or “positions”).</p>
</dd></dl>
<dl class="method">
<dt id="whoosh.formats.Format.word_values">
<tt class="descname">word_values</tt><big>(</big><em>value</em>, <em>analyzer</em>, <em>**kwargs</em><big>)</big><a class="headerlink" href="#whoosh.formats.Format.word_values" title="Permalink to this definition">¶</a></dt>
<dd><p>Takes the text value to be indexed and yields a series of
(“tokentext”, frequency, weight, valuestring) tuples, where frequency
is the number of times “tokentext” appeared in the value, weight is the
weight (a float usually equal to frequency in the absence of per-term
boosts) and valuestring is encoded field-specific posting value for the
token. For example, in a Frequency format, the value string would be
the same as frequency; in a Positions format, the value string would
encode a list of token positions at which “tokentext” occured.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first last simple">
<li><strong>value</strong> – The unicode text to index.</li>
<li><strong>analyzer</strong> – The analyzer to use to process the text.</li>
</ul>
</td>
</tr>
</tbody>
</table>
</dd></dl>
</dd></dl>
</div>
<div class="section" id="formats">
<h2>Formats<a class="headerlink" href="#formats" title="Permalink to this headline">¶</a></h2>
<dl class="class">
<dt id="whoosh.formats.Existence">
<em class="property">class </em><tt class="descclassname">whoosh.formats.</tt><tt class="descname">Existence</tt><big>(</big><em>field_boost=1.0</em>, <em>**options</em><big>)</big><a class="headerlink" href="#whoosh.formats.Existence" title="Permalink to this definition">¶</a></dt>
<dd><p>Only indexes whether a given term occurred in a given document; it does
not store frequencies or positions. This is useful for fields that should
be searchable but not scorable, such as file path.</p>
<p>Supports: frequency, weight (always reports frequency = 1).</p>
</dd></dl>
<dl class="class">
<dt id="whoosh.formats.Frequency">
<em class="property">class </em><tt class="descclassname">whoosh.formats.</tt><tt class="descname">Frequency</tt><big>(</big><em>field_boost=1.0</em>, <em>boost_as_freq=False</em>, <em>**options</em><big>)</big><a class="headerlink" href="#whoosh.formats.Frequency" title="Permalink to this definition">¶</a></dt>
<dd><p>Stores frequency information for each posting.</p>
<p>Supports: frequency, weight.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>field_boost</strong> – A constant boost factor to scale to the score of
all queries matching terms in this field.</td>
</tr>
</tbody>
</table>
</dd></dl>
<dl class="class">
<dt id="whoosh.formats.Positions">
<em class="property">class </em><tt class="descclassname">whoosh.formats.</tt><tt class="descname">Positions</tt><big>(</big><em>field_boost=1.0</em>, <em>**options</em><big>)</big><a class="headerlink" href="#whoosh.formats.Positions" title="Permalink to this definition">¶</a></dt>
<dd><p>Stores position information in each posting, to allow phrase searching
and “near” queries.</p>
<p>Supports: frequency, weight, positions, position_boosts (always reports
position boost = 1.0).</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>field_boost</strong> – A constant boost factor to scale to the score
of all queries matching terms in this field.</td>
</tr>
</tbody>
</table>
</dd></dl>
<dl class="class">
<dt id="whoosh.formats.Characters">
<em class="property">class </em><tt class="descclassname">whoosh.formats.</tt><tt class="descname">Characters</tt><big>(</big><em>field_boost=1.0</em>, <em>**options</em><big>)</big><a class="headerlink" href="#whoosh.formats.Characters" title="Permalink to this definition">¶</a></dt>
<dd><p>Stores token position and character start and end information for each
posting.</p>
<p>Supports: frequency, weight, positions, position_boosts (always reports
position boost = 1.0), characters.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>field_boost</strong> – A constant boost factor to scale to the score
of all queries matching terms in this field.</td>
</tr>
</tbody>
</table>
</dd></dl>
<dl class="class">
<dt id="whoosh.formats.PositionBoosts">
<em class="property">class </em><tt class="descclassname">whoosh.formats.</tt><tt class="descname">PositionBoosts</tt><big>(</big><em>field_boost=1.0</em>, <em>**options</em><big>)</big><a class="headerlink" href="#whoosh.formats.PositionBoosts" title="Permalink to this definition">¶</a></dt>
<dd><p>A format that stores positions and per-position boost information
in each posting.</p>
<p>Supports: frequency, weight, positions, position_boosts.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>field_boost</strong> – A constant boost factor to scale to the score
of all queries matching terms in this field.</td>
</tr>
</tbody>
</table>
</dd></dl>
<dl class="class">
<dt id="whoosh.formats.CharacterBoosts">
<em class="property">class </em><tt class="descclassname">whoosh.formats.</tt><tt class="descname">CharacterBoosts</tt><big>(</big><em>field_boost=1.0</em>, <em>**options</em><big>)</big><a class="headerlink" href="#whoosh.formats.CharacterBoosts" title="Permalink to this definition">¶</a></dt>
<dd><p>A format that stores positions, character start and end, and
per-position boost information in each posting.</p>
<p>Supports: frequency, weight, positions, position_boosts, characters,
character_boosts.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><strong>field_boost</strong> – A constant boost factor to scale to the score
of all queries matching terms in this field.</td>
</tr>
</tbody>
</table>
</dd></dl>
</div>
</div>
</div>
</div>
</div>
<div class="sphinxsidebar">
<div class="sphinxsidebarwrapper">
<h3><a href="../index.html">Table Of Contents</a></h3>
<ul>
<li><a class="reference internal" href="#"><tt class="docutils literal"><span class="pre">formats</span></tt> module</a><ul>
<li><a class="reference internal" href="#base-class">Base class</a></li>
<li><a class="reference internal" href="#formats">Formats</a></li>
</ul>
</li>
</ul>
<h4>Previous topic</h4>
<p class="topless"><a href="filedb/structfile.html"
title="previous chapter"><tt class="docutils literal"><span class="pre">filedb.structfile</span></tt> module</a></p>
<h4>Next topic</h4>
<p class="topless"><a href="highlight.html"
title="next chapter"><tt class="docutils literal"><span class="pre">highlight</span></tt> module</a></p>
<h3>This Page</h3>
<ul class="this-page-menu">
<li><a href="../_sources/api/formats.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="highlight.html" title="highlight module"
>next</a> |</li>
<li class="right" >
<a href="filedb/structfile.html" title="filedb.structfile module"
>previous</a> |</li>
<li><a href="../index.html">Whoosh 2.5.7 documentation</a> »</li>
<li><a href="api.html" >Whoosh API</a> »</li>
</ul>
</div>
<div class="footer">
© Copyright 2007-2012 Matt Chaput.
Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 1.1.3.
</div>
</body>
</html>
