| Current Path : /proc/2/root/usr/share/doc/python-docs-2.6.6/html/library/ |
| Current File : //proc/2/root/usr/share/doc/python-docs-2.6.6/html/library/future_builtins.html |
<!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>27.3. future_builtins — Python 3 builtins — Python v2.6.6 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: '2.6.6',
COLLAPSE_MODINDEX: false,
FILE_SUFFIX: '.html',
HAS_SOURCE: true
};
</script>
<script type="text/javascript" src="../_static/jquery.js"></script>
<script type="text/javascript" src="../_static/doctools.js"></script>
<link rel="search" type="application/opensearchdescription+xml"
title="Search within Python v2.6.6 documentation"
href="../_static/opensearch.xml"/>
<link rel="author" title="About these documents" href="../about.html" />
<link rel="copyright" title="Copyright" href="../copyright.html" />
<link rel="top" title="Python v2.6.6 documentation" href="../index.html" />
<link rel="up" title="27. Python Runtime Services" href="python.html" />
<link rel="next" title="27.4. __main__ — Top-level script environment" href="__main__.html" />
<link rel="prev" title="27.2. __builtin__ — Built-in objects" href="__builtin__.html" />
<link rel="shortcut icon" type="image/png" href="../_static/py.png" />
</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="../modindex.html" title="Global Module Index"
accesskey="M">modules</a> |</li>
<li class="right" >
<a href="__main__.html" title="27.4. __main__ — Top-level script environment"
accesskey="N">next</a> |</li>
<li class="right" >
<a href="__builtin__.html" title="27.2. __builtin__ — Built-in objects"
accesskey="P">previous</a> |</li>
<li><img src="../_static/py.png" alt=""
style="vertical-align: middle; margin-top: -1px"/></li>
<li><a href="../index.html">Python v2.6.6 documentation</a> »</li>
<li><a href="index.html" >The Python Standard Library</a> »</li>
<li><a href="python.html" accesskey="U">27. Python Runtime Services</a> »</li>
</ul>
</div>
<div class="document">
<div class="documentwrapper">
<div class="bodywrapper">
<div class="body">
<div class="section" id="module-future_builtins">
<h1>27.3. <tt class="xref docutils literal"><span class="pre">future_builtins</span></tt> — Python 3 builtins<a class="headerlink" href="#module-future_builtins" title="Permalink to this headline">¶</a></h1>
<p class="versionadded">
<span class="versionmodified">New in version 2.6.</span></p>
<p>This module provides functions that exist in 2.x, but have different behavior in
Python 3, so they cannot be put into the 2.x builtins namespace.</p>
<p>Instead, if you want to write code compatible with Python 3 builtins, import
them from this module, like this:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="kn">from</span> <span class="nn">future_builtins</span> <span class="kn">import</span> <span class="nb">map</span><span class="p">,</span> <span class="nb">filter</span>
<span class="o">...</span> <span class="n">code</span> <span class="n">using</span> <span class="n">Python</span> <span class="mi">3</span><span class="o">-</span><span class="n">style</span> <span class="nb">map</span> <span class="ow">and</span> <span class="nb">filter</span> <span class="o">...</span>
</pre></div>
</div>
<p>The <a class="reference external" href="../glossary.html#term-to3"><em class="xref">2to3</em></a> tool that ports Python 2 code to Python 3 will recognize
this usage and leave the new builtins alone.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p>The Python 3 <a title="print" class="reference external" href="functions.html#print"><tt class="xref docutils literal"><span class="pre">print()</span></tt></a> function is already in the builtins, but cannot be
accessed from Python 2 code unless you use the appropriate future statement:</p>
<div class="last highlight-python"><div class="highlight"><pre><span class="kn">from</span> <span class="nn">__future__</span> <span class="kn">import</span> <span class="n">print_function</span>
</pre></div>
</div>
</div>
<p>Available builtins are:</p>
<dl class="function">
<dt id="future_builtins.ascii">
<tt class="descclassname">future_builtins.</tt><tt class="descname">ascii</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#future_builtins.ascii" title="Permalink to this definition">¶</a></dt>
<dd>Returns the same as <a title="repr" class="reference external" href="functions.html#repr"><tt class="xref docutils literal"><span class="pre">repr()</span></tt></a>. In Python 3, <a title="repr" class="reference external" href="functions.html#repr"><tt class="xref docutils literal"><span class="pre">repr()</span></tt></a> will return
printable Unicode characters unescaped, while <a title="future_builtins.ascii" class="reference internal" href="#future_builtins.ascii"><tt class="xref docutils literal"><span class="pre">ascii()</span></tt></a> will always
backslash-escape them. Using <a title="future_builtins.ascii" class="reference internal" href="#future_builtins.ascii"><tt class="xref docutils literal"><span class="pre">future_builtins.ascii()</span></tt></a> instead of
<a title="repr" class="reference external" href="functions.html#repr"><tt class="xref docutils literal"><span class="pre">repr()</span></tt></a> in 2.6 code makes it clear that you need a pure ASCII return
value.</dd></dl>
<dl class="function">
<dt id="future_builtins.filter">
<tt class="descclassname">future_builtins.</tt><tt class="descname">filter</tt><big>(</big><em>function</em>, <em>iterable</em><big>)</big><a class="headerlink" href="#future_builtins.filter" title="Permalink to this definition">¶</a></dt>
<dd>Works like <a title="itertools.ifilter" class="reference external" href="itertools.html#itertools.ifilter"><tt class="xref docutils literal"><span class="pre">itertools.ifilter()</span></tt></a>.</dd></dl>
<dl class="function">
<dt id="future_builtins.hex">
<tt class="descclassname">future_builtins.</tt><tt class="descname">hex</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#future_builtins.hex" title="Permalink to this definition">¶</a></dt>
<dd>Works like the built-in <a title="hex" class="reference external" href="functions.html#hex"><tt class="xref docutils literal"><span class="pre">hex()</span></tt></a>, but instead of <a title="object.__hex__" class="reference external" href="../reference/datamodel.html#object.__hex__"><tt class="xref docutils literal"><span class="pre">__hex__()</span></tt></a> it will
use the <a title="object.__index__" class="reference external" href="../reference/datamodel.html#object.__index__"><tt class="xref docutils literal"><span class="pre">__index__()</span></tt></a> method on its argument to get an integer that is
then converted to hexadecimal.</dd></dl>
<dl class="function">
<dt id="future_builtins.map">
<tt class="descclassname">future_builtins.</tt><tt class="descname">map</tt><big>(</big><em>function</em>, <em>iterable</em>, <em>...</em><big>)</big><a class="headerlink" href="#future_builtins.map" title="Permalink to this definition">¶</a></dt>
<dd>Works like <a title="itertools.imap" class="reference external" href="itertools.html#itertools.imap"><tt class="xref docutils literal"><span class="pre">itertools.imap()</span></tt></a>.</dd></dl>
<dl class="function">
<dt id="future_builtins.oct">
<tt class="descclassname">future_builtins.</tt><tt class="descname">oct</tt><big>(</big><em>object</em><big>)</big><a class="headerlink" href="#future_builtins.oct" title="Permalink to this definition">¶</a></dt>
<dd>Works like the built-in <a title="oct" class="reference external" href="functions.html#oct"><tt class="xref docutils literal"><span class="pre">oct()</span></tt></a>, but instead of <a title="object.__oct__" class="reference external" href="../reference/datamodel.html#object.__oct__"><tt class="xref docutils literal"><span class="pre">__oct__()</span></tt></a> it will
use the <a title="object.__index__" class="reference external" href="../reference/datamodel.html#object.__index__"><tt class="xref docutils literal"><span class="pre">__index__()</span></tt></a> method on its argument to get an integer that is
then converted to octal.</dd></dl>
<dl class="function">
<dt id="future_builtins.zip">
<tt class="descclassname">future_builtins.</tt><tt class="descname">zip</tt><big>(</big><em>*iterables</em><big>)</big><a class="headerlink" href="#future_builtins.zip" title="Permalink to this definition">¶</a></dt>
<dd>Works like <a title="itertools.izip" class="reference external" href="itertools.html#itertools.izip"><tt class="xref docutils literal"><span class="pre">itertools.izip()</span></tt></a>.</dd></dl>
</div>
</div>
</div>
</div>
<div class="sphinxsidebar">
<div class="sphinxsidebarwrapper">
<h4>Previous topic</h4>
<p class="topless"><a href="__builtin__.html"
title="previous chapter">27.2. <tt class="docutils literal docutils literal"><span class="pre">__builtin__</span></tt> — Built-in objects</a></p>
<h4>Next topic</h4>
<p class="topless"><a href="__main__.html"
title="next chapter">27.4. <tt class="docutils literal docutils literal"><span class="pre">__main__</span></tt> — Top-level script environment</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/future_builtins.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" size="18" />
<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="../modindex.html" title="Global Module Index"
>modules</a> |</li>
<li class="right" >
<a href="__main__.html" title="27.4. __main__ — Top-level script environment"
>next</a> |</li>
<li class="right" >
<a href="__builtin__.html" title="27.2. __builtin__ — Built-in objects"
>previous</a> |</li>
<li><img src="../_static/py.png" alt=""
style="vertical-align: middle; margin-top: -1px"/></li>
<li><a href="../index.html">Python v2.6.6 documentation</a> »</li>
<li><a href="index.html" >The Python Standard Library</a> »</li>
<li><a href="python.html" >27. Python Runtime Services</a> »</li>
</ul>
</div>
<div class="footer">
© <a href="../copyright.html">Copyright</a> 1990-2011, Python Software Foundation.
<br />
The Python Software Foundation is a non-profit corporation.
<a href="http://www.python.org/psf/donations/">Please donate.</a>
<br />
Last updated on Jul 20, 2011.
<a href="../bugs.html">Found a bug</a>?
<br />
Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 0.6.6.
</div>
</body>
</html>Copyright 2K16 - 2K18 Indonesian Hacker Rulez
;?>)