<?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.util.LRUCache</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.util-module.html">Module util</a> :: Class LRUCache </span> </td> <td> <table cellpadding="0" cellspacing="0"> <!-- hide/show private --> </table> </td> </tr> </table> <!-- ==================== CLASS DESCRIPTION ==================== --> <h1 class="epydoc">Class LRUCache</h1><p class="nomargin-top"></p> <pre class="base-tree"> object --+ | dict --+ | <strong class="uidshort">LRUCache</strong> </pre> <hr /> <p>A dictionary-like object that stores only a certain number of items, and discards its least recently used item when full.</p> <pre class="py-doctest"> <span class="py-prompt">>>> </span>cache = LRUCache(3) <span class="py-prompt">>>> </span>cache[<span class="py-string">'A'</span>] = 0 <span class="py-prompt">>>> </span>cache[<span class="py-string">'B'</span>] = 1 <span class="py-prompt">>>> </span>cache[<span class="py-string">'C'</span>] = 2 <span class="py-prompt">>>> </span>len(cache) <span class="py-output">3</span></pre> <pre class="py-doctest"> <span class="py-prompt">>>> </span>cache[<span class="py-string">'A'</span>] <span class="py-output">0</span></pre> <p>Adding new items to the cache does not increase its size. Instead, the least recently used item is dropped:</p> <pre class="py-doctest"> <span class="py-prompt">>>> </span>cache[<span class="py-string">'D'</span>] = 3 <span class="py-prompt">>>> </span>len(cache) <span class="py-output">3</span> <span class="py-output"></span><span class="py-prompt">>>> </span><span class="py-string">'B'</span> <span class="py-keyword">in</span> cache <span class="py-output">False</span></pre> <p>Iterating over the cache returns the keys, starting with the most recently used:</p> <pre class="py-doctest"> <span class="py-prompt">>>> </span><span class="py-keyword">for</span> key <span class="py-keyword">in</span> cache: <span class="py-more">... </span> <span class="py-keyword">print</span>(key) <span class="py-output">D</span> <span class="py-output">A</span> <span class="py-output">C</span></pre> <p>This code is based on the LRUCache class from <tt class="rst-docutils literal">myghtyutils.util</tt>, written by Mike Bayer and released under the MIT license. See:</p> <blockquote> <a class="rst-reference external" href="http://svn.myghty.org/myghtyutils/trunk/lib/myghtyutils/util.py" target="_top">http://svn.myghty.org/myghtyutils/trunk/lib/myghtyutils/util.py</a></blockquote> <!-- ==================== 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"><pre class="literalblock"> new empty dictionary </pre></span> </td><td class="summary"> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr> <td><span class="summary-sig"><a href="genshi.util.LRUCache-class.html#__init__" class="summary-sig-name">__init__</a>(<span class="summary-sig-arg">self</span>, <span class="summary-sig-arg">capacity</span>)</span><br /> x.__init__(...) initializes x; see help(type(x)) for signature</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">True if D has a key k, else False</span> </td><td class="summary"> <table width="100%" cellpadding="0" cellspacing="0" border="0"> <tr> <td><span class="summary-sig"><a href="genshi.util.LRUCache-class.html#__contains__" class="summary-sig-name">__contains__</a>(<span class="summary-sig-arg">self</span>, <span class="summary-sig-arg">key</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 href="genshi.util.LRUCache-class.html#__iter__" class="summary-sig-name">__iter__</a>(<span class="summary-sig-arg">self</span>)</span><br /> iter(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 href="genshi.util.LRUCache-class.html#__len__" class="summary-sig-name">__len__</a>(<span class="summary-sig-arg">self</span>)</span><br /> len(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 href="genshi.util.LRUCache-class.html#__getitem__" class="summary-sig-name">__getitem__</a>(<span class="summary-sig-arg">self</span>, <span class="summary-sig-arg">key</span>)</span><br /> x[y]</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.util.LRUCache-class.html#__setitem__" class="summary-sig-name">__setitem__</a>(<span class="summary-sig-arg">self</span>, <span class="summary-sig-arg">key</span>, <span class="summary-sig-arg">value</span>)</span><br /> x[i]=y</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.util.LRUCache-class.html#__repr__" class="summary-sig-name">__repr__</a>(<span class="summary-sig-arg">self</span>)</span><br /> repr(x)</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>dict</code></b>: <code>__cmp__</code>, <code>__delitem__</code>, <code>__eq__</code>, <code>__ge__</code>, <code>__getattribute__</code>, <code>__gt__</code>, <code>__le__</code>, <code>__lt__</code>, <code>__ne__</code>, <code>__new__</code>, <code>__sizeof__</code>, <code>clear</code>, <code>copy</code>, <code>fromkeys</code>, <code>get</code>, <code>has_key</code>, <code>items</code>, <code>iteritems</code>, <code>iterkeys</code>, <code>itervalues</code>, <code>keys</code>, <code>pop</code>, <code>popitem</code>, <code>setdefault</code>, <code>update</code>, <code>values</code>, <code>viewitems</code>, <code>viewkeys</code>, <code>viewvalues</code> </p> <p class="indent-wrapped-lines"><b>Inherited from <code>object</code></b>: <code>__delattr__</code>, <code>__format__</code>, <code>__reduce__</code>, <code>__reduce_ex__</code>, <code>__setattr__</code>, <code>__str__</code>, <code>__subclasshook__</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 colspan="2" class="summary"> <p class="indent-wrapped-lines"><b>Inherited from <code>dict</code></b>: <code>__hash__</code> </p> </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">capacity</span>)</span> <br /><em class="fname">(Constructor)</em> </h3> </td><td align="right" valign="top" > </td> </tr></table> x.__init__(...) initializes x; see help(type(x)) for signature <dl class="fields"> <dt>Returns: <pre class="literalblock"> new empty dictionary </pre></dt> <dt>Overrides: object.__init__ <dd><em class="note">(inherited documentation)</em></dd> </dt> </dl> </td></tr></table> </div> <a name="__contains__"></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">__contains__</span>(<span class="sig-arg">self</span>, <span class="sig-arg">key</span>)</span> <br /><em class="fname">(In operator)</em> </h3> </td><td align="right" valign="top" > </td> </tr></table> <dl class="fields"> <dt>Returns: True if D has a key k, else False</dt> <dt>Overrides: dict.__contains__ <dd><em class="note">(inherited documentation)</em></dd> </dt> </dl> </td></tr></table> </div> <a name="__iter__"></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">__iter__</span>(<span class="sig-arg">self</span>)</span> </h3> </td><td align="right" valign="top" > </td> </tr></table> iter(x) <dl class="fields"> <dt>Overrides: dict.__iter__ <dd><em class="note">(inherited documentation)</em></dd> </dt> </dl> </td></tr></table> </div> <a name="__len__"></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">__len__</span>(<span class="sig-arg">self</span>)</span> <br /><em class="fname">(Length operator)</em> </h3> </td><td align="right" valign="top" > </td> </tr></table> len(x) <dl class="fields"> <dt>Overrides: dict.__len__ <dd><em class="note">(inherited documentation)</em></dd> </dt> </dl> </td></tr></table> </div> <a name="__getitem__"></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">__getitem__</span>(<span class="sig-arg">self</span>, <span class="sig-arg">key</span>)</span> <br /><em class="fname">(Indexing operator)</em> </h3> </td><td align="right" valign="top" > </td> </tr></table> x[y] <dl class="fields"> <dt>Overrides: dict.__getitem__ <dd><em class="note">(inherited documentation)</em></dd> </dt> </dl> </td></tr></table> </div> <a name="__setitem__"></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">__setitem__</span>(<span class="sig-arg">self</span>, <span class="sig-arg">key</span>, <span class="sig-arg">value</span>)</span> <br /><em class="fname">(Index assignment operator)</em> </h3> </td><td align="right" valign="top" > </td> </tr></table> x[i]=y <dl class="fields"> <dt>Overrides: dict.__setitem__ <dd><em class="note">(inherited documentation)</em></dd> </dt> </dl> </td></tr></table> </div> <a name="__repr__"></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">__repr__</span>(<span class="sig-arg">self</span>)</span> <br /><em class="fname">(Representation operator)</em> </h3> </td><td align="right" valign="top" > </td> </tr></table> repr(x) <dl class="fields"> <dt>Overrides: object.__repr__ <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 Sun Jan 27 18:17:20 2013 </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); but by default, we want to hide them. So hide // them unless we have a cookie that says to show them. checkCookie(); // --> </script> </body> </html>