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<!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="X-UA-Compatible" content="IE=Edge" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>25.4. 2to3 - Automated Python 2 to 3 code translation — Python 2.7.18 documentation</title> <link rel="stylesheet" href="../_static/classic.css" type="text/css" /> <link rel="stylesheet" href="../_static/pygments.css" type="text/css" /> <script type="text/javascript" id="documentation_options" data-url_root="../" src="../_static/documentation_options.js"></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> <script type="text/javascript" src="../_static/language_data.js"></script> <script type="text/javascript" src="../_static/sidebar.js"></script> <link rel="search" type="application/opensearchdescription+xml" title="Search within Python 2.7.18 documentation" href="../_static/opensearch.xml"/> <link rel="author" title="About these documents" href="../about.html" /> <link rel="index" title="Index" href="../genindex.html" /> <link rel="search" title="Search" href="../search.html" /> <link rel="copyright" title="Copyright" href="../copyright.html" /> <link rel="next" title="25.5. test — Regression tests package for Python" href="test.html" /> <link rel="prev" title="25.3. unittest — Unit testing framework" href="unittest.html" /> <link rel="shortcut icon" type="image/png" href="../_static/py.png" /> <link rel="canonical" href="file:///usr/share/doc/python2.7/html/library/2to3.html" /> <script type="text/javascript" src="../_static/copybutton.js"></script> </head><body> <div id="outdated-warning" style="padding: .5em; text-align: center; background-color: #FFBABA; color: #6A0E0E;"> This document is for an old version of Python that is <a href="https://devguide.python.org/devcycle/#end-of-life-branches">no longer supported</a>. You should install the python3 and python3-doc packages and read the <a href="file:///usr/share/doc/python3-doc/html/library/2to3.html"> Python documentation for the Python3 version packaged in this release</a>. </div> <div class="related" role="navigation" aria-label="related navigation"> <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="test.html" title="25.5. test — Regression tests package for Python" accesskey="N">next</a> |</li> <li class="right" > <a href="unittest.html" title="25.3. unittest — Unit testing framework" accesskey="P">previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="https://www.python.org/">Python</a> »</li> <li> <a href="../index.html">Python 2.7.18 documentation</a> » </li> <li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> »</li> <li class="nav-item nav-item-2"><a href="development.html" accesskey="U">25. Development Tools</a> »</li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body" role="main"> <div class="section" id="to3-automated-python-2-to-3-code-translation"> <span id="to3-reference"></span><h1>25.4. 2to3 - Automated Python 2 to 3 code translation<a class="headerlink" href="#to3-automated-python-2-to-3-code-translation" title="Permalink to this headline">¶</a></h1> <p>2to3 is a Python program that reads Python 2.x source code and applies a series of <em>fixers</em> to transform it into valid Python 3.x code. The standard library contains a rich set of fixers that will handle almost all code. 2to3 supporting library <a class="reference internal" href="#module-lib2to3" title="lib2to3: the 2to3 library"><code class="xref py py-mod docutils literal notranslate"><span class="pre">lib2to3</span></code></a> is, however, a flexible and generic library, so it is possible to write your own fixers for 2to3. <a class="reference internal" href="#module-lib2to3" title="lib2to3: the 2to3 library"><code class="xref py py-mod docutils literal notranslate"><span class="pre">lib2to3</span></code></a> could also be adapted to custom applications in which Python code needs to be edited automatically.</p> <div class="section" id="using-2to3"> <span id="to3-using"></span><h2>25.4.1. Using 2to3<a class="headerlink" href="#using-2to3" title="Permalink to this headline">¶</a></h2> <p>2to3 will usually be installed with the Python interpreter as a script. It is also located in the <code class="file docutils literal notranslate"><span class="pre">Tools/scripts</span></code> directory of the Python root.</p> <p>2to3’s basic arguments are a list of files or directories to transform. The directories are recursively traversed for Python sources.</p> <p>Here is a sample Python 2.x source file, <code class="file docutils literal notranslate"><span class="pre">example.py</span></code>:</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">greet</span><span class="p">(</span><span class="n">name</span><span class="p">):</span> <span class="nb">print</span> <span class="s2">"Hello, </span><span class="si">{0}</span><span class="s2">!"</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="n">name</span><span class="p">)</span> <span class="nb">print</span> <span class="s2">"What's your name?"</span> <span class="n">name</span> <span class="o">=</span> <span class="n">raw_input</span><span class="p">()</span> <span class="n">greet</span><span class="p">(</span><span class="n">name</span><span class="p">)</span> </pre></div> </div> <p>It can be converted to Python 3.x code via 2to3 on the command line:</p> <div class="highlight-shell-session notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> 2to3 example.py </pre></div> </div> <p>A diff against the original source file is printed. 2to3 can also write the needed modifications right back to the source file. (A backup of the original file is made unless <code class="xref std std-option docutils literal notranslate"><span class="pre">-n</span></code> is also given.) Writing the changes back is enabled with the <code class="xref std std-option docutils literal notranslate"><span class="pre">-w</span></code> flag:</p> <div class="highlight-shell-session notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> 2to3 -w example.py </pre></div> </div> <p>After transformation, <code class="file docutils literal notranslate"><span class="pre">example.py</span></code> looks like this:</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="k">def</span> <span class="nf">greet</span><span class="p">(</span><span class="n">name</span><span class="p">):</span> <span class="nb">print</span><span class="p">(</span><span class="s2">"Hello, </span><span class="si">{0}</span><span class="s2">!"</span><span class="o">.</span><span class="n">format</span><span class="p">(</span><span class="n">name</span><span class="p">))</span> <span class="nb">print</span><span class="p">(</span><span class="s2">"What's your name?"</span><span class="p">)</span> <span class="n">name</span> <span class="o">=</span> <span class="nb">input</span><span class="p">()</span> <span class="n">greet</span><span class="p">(</span><span class="n">name</span><span class="p">)</span> </pre></div> </div> <p>Comments and exact indentation are preserved throughout the translation process.</p> <p>By default, 2to3 runs a set of <a class="reference internal" href="#to3-fixers"><span class="std std-ref">predefined fixers</span></a>. The <code class="xref std std-option docutils literal notranslate"><span class="pre">-l</span></code> flag lists all available fixers. An explicit set of fixers to run can be given with <code class="xref std std-option docutils literal notranslate"><span class="pre">-f</span></code>. Likewise the <code class="xref std std-option docutils literal notranslate"><span class="pre">-x</span></code> explicitly disables a fixer. The following example runs only the <code class="docutils literal notranslate"><span class="pre">imports</span></code> and <code class="docutils literal notranslate"><span class="pre">has_key</span></code> fixers:</p> <div class="highlight-shell-session notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> 2to3 -f imports -f has_key example.py </pre></div> </div> <p>This command runs every fixer except the <code class="docutils literal notranslate"><span class="pre">apply</span></code> fixer:</p> <div class="highlight-shell-session notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> 2to3 -x apply example.py </pre></div> </div> <p>Some fixers are <em>explicit</em>, meaning they aren’t run by default and must be listed on the command line to be run. Here, in addition to the default fixers, the <code class="docutils literal notranslate"><span class="pre">idioms</span></code> fixer is run:</p> <div class="highlight-shell-session notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> 2to3 -f all -f idioms example.py </pre></div> </div> <p>Notice how passing <code class="docutils literal notranslate"><span class="pre">all</span></code> enables all default fixers.</p> <p>Sometimes 2to3 will find a place in your source code that needs to be changed, but 2to3 cannot fix automatically. In this case, 2to3 will print a warning beneath the diff for a file. You should address the warning in order to have compliant 3.x code.</p> <p>2to3 can also refactor doctests. To enable this mode, use the <code class="xref std std-option docutils literal notranslate"><span class="pre">-d</span></code> flag. Note that <em>only</em> doctests will be refactored. This also doesn’t require the module to be valid Python. For example, doctest like examples in a reST document could also be refactored with this option.</p> <p>The <code class="xref std std-option docutils literal notranslate"><span class="pre">-v</span></code> option enables output of more information on the translation process.</p> <p>Since some print statements can be parsed as function calls or statements, 2to3 cannot always read files containing the print function. When 2to3 detects the presence of the <code class="docutils literal notranslate"><span class="pre">from</span> <span class="pre">__future__</span> <span class="pre">import</span> <span class="pre">print_function</span></code> compiler directive, it modifies its internal grammar to interpret <a class="reference internal" href="functions.html#print" title="print"><code class="xref py py-func docutils literal notranslate"><span class="pre">print()</span></code></a> as a function. This change can also be enabled manually with the <code class="xref std std-option docutils literal notranslate"><span class="pre">-p</span></code> flag. Use <code class="xref std std-option docutils literal notranslate"><span class="pre">-p</span></code> to run fixers on code that already has had its print statements converted.</p> <p>The <code class="xref std std-option docutils literal notranslate"><span class="pre">-o</span></code> or <code class="xref std std-option docutils literal notranslate"><span class="pre">--output-dir</span></code> option allows specification of an alternate directory for processed output files to be written to. The <code class="xref std std-option docutils literal notranslate"><span class="pre">-n</span></code> flag is required when using this as backup files do not make sense when not overwriting the input files.</p> <div class="versionadded"> <p><span class="versionmodified">New in version 2.7.3: </span>The <code class="xref std std-option docutils literal notranslate"><span class="pre">-o</span></code> option was added.</p> </div> <p>The <code class="xref std std-option docutils literal notranslate"><span class="pre">-W</span></code> or <code class="xref std std-option docutils literal notranslate"><span class="pre">--write-unchanged-files</span></code> flag tells 2to3 to always write output files even if no changes were required to the file. This is most useful with <code class="xref std std-option docutils literal notranslate"><span class="pre">-o</span></code> so that an entire Python source tree is copied with translation from one directory to another. This option implies the <code class="xref std std-option docutils literal notranslate"><span class="pre">-w</span></code> flag as it would not make sense otherwise.</p> <div class="versionadded"> <p><span class="versionmodified">New in version 2.7.3: </span>The <code class="xref std std-option docutils literal notranslate"><span class="pre">-W</span></code> flag was added.</p> </div> <p>The <code class="xref std std-option docutils literal notranslate"><span class="pre">--add-suffix</span></code> option specifies a string to append to all output filenames. The <code class="xref std std-option docutils literal notranslate"><span class="pre">-n</span></code> flag is required when specifying this as backups are not necessary when writing to different filenames. Example:</p> <div class="highlight-shell-session notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> 2to3 -n -W --add-suffix<span class="o">=</span><span class="m">3</span> example.py </pre></div> </div> <p>Will cause a converted file named <code class="docutils literal notranslate"><span class="pre">example.py3</span></code> to be written.</p> <div class="versionadded"> <p><span class="versionmodified">New in version 2.7.3: </span>The <code class="xref std std-option docutils literal notranslate"><span class="pre">--add-suffix</span></code> option was added.</p> </div> <p>To translate an entire project from one directory tree to another use:</p> <div class="highlight-shell-session notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> 2to3 --output-dir<span class="o">=</span>python3-version/mycode -W -n python2-version/mycode </pre></div> </div> </div> <div class="section" id="fixers"> <span id="to3-fixers"></span><h2>25.4.2. Fixers<a class="headerlink" href="#fixers" title="Permalink to this headline">¶</a></h2> <p>Each step of transforming code is encapsulated in a fixer. The command <code class="docutils literal notranslate"><span class="pre">2to3</span> <span class="pre">-l</span></code> lists them. As <a class="reference internal" href="#to3-using"><span class="std std-ref">documented above</span></a>, each can be turned on and off individually. They are described here in more detail.</p> <dl class="2to3fixer"> <dt id="2to3fixer-apply"> <code class="descname">apply</code><a class="headerlink" href="#2to3fixer-apply" title="Permalink to this definition">¶</a></dt> <dd><p>Removes usage of <a class="reference internal" href="functions.html#apply" title="apply"><code class="xref py py-func docutils literal notranslate"><span class="pre">apply()</span></code></a>. For example <code class="docutils literal notranslate"><span class="pre">apply(function,</span> <span class="pre">*args,</span> <span class="pre">**kwargs)</span></code> is converted to <code class="docutils literal notranslate"><span class="pre">function(*args,</span> <span class="pre">**kwargs)</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-asserts"> <code class="descname">asserts</code><a class="headerlink" href="#2to3fixer-asserts" title="Permalink to this definition">¶</a></dt> <dd><p>Replaces deprecated <a class="reference internal" href="unittest.html#module-unittest" title="unittest: Unit testing framework for Python."><code class="xref py py-mod docutils literal notranslate"><span class="pre">unittest</span></code></a> method names with the correct ones.</p> <table border="1" class="docutils"> <colgroup> <col width="43%" /> <col width="57%" /> </colgroup> <thead valign="bottom"> <tr class="row-odd"><th class="head">From</th> <th class="head">To</th> </tr> </thead> <tbody valign="top"> <tr class="row-even"><td><code class="docutils literal notranslate"><span class="pre">failUnlessEqual(a,</span> <span class="pre">b)</span></code></td> <td><a class="reference internal" href="unittest.html#unittest.TestCase.assertEqual" title="unittest.TestCase.assertEqual"><code class="xref py py-meth docutils literal notranslate"><span class="pre">assertEqual(a,</span> <span class="pre">b)</span></code></a></td> </tr> <tr class="row-odd"><td><code class="docutils literal notranslate"><span class="pre">assertEquals(a,</span> <span class="pre">b)</span></code></td> <td><a class="reference internal" href="unittest.html#unittest.TestCase.assertEqual" title="unittest.TestCase.assertEqual"><code class="xref py py-meth docutils literal notranslate"><span class="pre">assertEqual(a,</span> <span class="pre">b)</span></code></a></td> </tr> <tr class="row-even"><td><code class="docutils literal notranslate"><span class="pre">failIfEqual(a,</span> <span class="pre">b)</span></code></td> <td><a class="reference internal" href="unittest.html#unittest.TestCase.assertNotEqual" title="unittest.TestCase.assertNotEqual"><code class="xref py py-meth docutils literal notranslate"><span class="pre">assertNotEqual(a,</span> <span class="pre">b)</span></code></a></td> </tr> <tr class="row-odd"><td><code class="docutils literal notranslate"><span class="pre">assertNotEquals(a,</span> <span class="pre">b)</span></code></td> <td><a class="reference internal" href="unittest.html#unittest.TestCase.assertNotEqual" title="unittest.TestCase.assertNotEqual"><code class="xref py py-meth docutils literal notranslate"><span class="pre">assertNotEqual(a,</span> <span class="pre">b)</span></code></a></td> </tr> <tr class="row-even"><td><code class="docutils literal notranslate"><span class="pre">failUnless(a)</span></code></td> <td><a class="reference internal" href="unittest.html#unittest.TestCase.assertTrue" title="unittest.TestCase.assertTrue"><code class="xref py py-meth docutils literal notranslate"><span class="pre">assertTrue(a)</span></code></a></td> </tr> <tr class="row-odd"><td><code class="docutils literal notranslate"><span class="pre">assert_(a)</span></code></td> <td><a class="reference internal" href="unittest.html#unittest.TestCase.assertTrue" title="unittest.TestCase.assertTrue"><code class="xref py py-meth docutils literal notranslate"><span class="pre">assertTrue(a)</span></code></a></td> </tr> <tr class="row-even"><td><code class="docutils literal notranslate"><span class="pre">failIf(a)</span></code></td> <td><a class="reference internal" href="unittest.html#unittest.TestCase.assertFalse" title="unittest.TestCase.assertFalse"><code class="xref py py-meth docutils literal notranslate"><span class="pre">assertFalse(a)</span></code></a></td> </tr> <tr class="row-odd"><td><code class="docutils literal notranslate"><span class="pre">failUnlessRaises(exc,</span> <span class="pre">cal)</span></code></td> <td><a class="reference internal" href="unittest.html#unittest.TestCase.assertRaises" title="unittest.TestCase.assertRaises"><code class="xref py py-meth docutils literal notranslate"><span class="pre">assertRaises(exc,</span> <span class="pre">cal)</span></code></a></td> </tr> <tr class="row-even"><td><code class="docutils literal notranslate"><span class="pre">failUnlessAlmostEqual(a,</span> <span class="pre">b)</span></code></td> <td><a class="reference internal" href="unittest.html#unittest.TestCase.assertAlmostEqual" title="unittest.TestCase.assertAlmostEqual"><code class="xref py py-meth docutils literal notranslate"><span class="pre">assertAlmostEqual(a,</span> <span class="pre">b)</span></code></a></td> </tr> <tr class="row-odd"><td><code class="docutils literal notranslate"><span class="pre">assertAlmostEquals(a,</span> <span class="pre">b)</span></code></td> <td><a class="reference internal" href="unittest.html#unittest.TestCase.assertAlmostEqual" title="unittest.TestCase.assertAlmostEqual"><code class="xref py py-meth docutils literal notranslate"><span class="pre">assertAlmostEqual(a,</span> <span class="pre">b)</span></code></a></td> </tr> <tr class="row-even"><td><code class="docutils literal notranslate"><span class="pre">failIfAlmostEqual(a,</span> <span class="pre">b)</span></code></td> <td><a class="reference internal" href="unittest.html#unittest.TestCase.assertNotAlmostEqual" title="unittest.TestCase.assertNotAlmostEqual"><code class="xref py py-meth docutils literal notranslate"><span class="pre">assertNotAlmostEqual(a,</span> <span class="pre">b)</span></code></a></td> </tr> <tr class="row-odd"><td><code class="docutils literal notranslate"><span class="pre">assertNotAlmostEquals(a,</span> <span class="pre">b)</span></code></td> <td><a class="reference internal" href="unittest.html#unittest.TestCase.assertNotAlmostEqual" title="unittest.TestCase.assertNotAlmostEqual"><code class="xref py py-meth docutils literal notranslate"><span class="pre">assertNotAlmostEqual(a,</span> <span class="pre">b)</span></code></a></td> </tr> </tbody> </table> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-basestring"> <code class="descname">basestring</code><a class="headerlink" href="#2to3fixer-basestring" title="Permalink to this definition">¶</a></dt> <dd><p>Converts <a class="reference internal" href="functions.html#basestring" title="basestring"><code class="xref py py-class docutils literal notranslate"><span class="pre">basestring</span></code></a> to <a class="reference internal" href="functions.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-buffer"> <code class="descname">buffer</code><a class="headerlink" href="#2to3fixer-buffer" title="Permalink to this definition">¶</a></dt> <dd><p>Converts <a class="reference internal" href="functions.html#buffer" title="buffer"><code class="xref py py-class docutils literal notranslate"><span class="pre">buffer</span></code></a> to <a class="reference internal" href="stdtypes.html#memoryview" title="memoryview"><code class="xref py py-class docutils literal notranslate"><span class="pre">memoryview</span></code></a>. This fixer is optional because the <a class="reference internal" href="stdtypes.html#memoryview" title="memoryview"><code class="xref py py-class docutils literal notranslate"><span class="pre">memoryview</span></code></a> API is similar but not exactly the same as that of <a class="reference internal" href="functions.html#buffer" title="buffer"><code class="xref py py-class docutils literal notranslate"><span class="pre">buffer</span></code></a>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-dict"> <code class="descname">dict</code><a class="headerlink" href="#2to3fixer-dict" title="Permalink to this definition">¶</a></dt> <dd><p>Fixes dictionary iteration methods. <a class="reference internal" href="stdtypes.html#dict.iteritems" title="dict.iteritems"><code class="xref py py-meth docutils literal notranslate"><span class="pre">dict.iteritems()</span></code></a> is converted to <a class="reference internal" href="stdtypes.html#dict.items" title="dict.items"><code class="xref py py-meth docutils literal notranslate"><span class="pre">dict.items()</span></code></a>, <a class="reference internal" href="stdtypes.html#dict.iterkeys" title="dict.iterkeys"><code class="xref py py-meth docutils literal notranslate"><span class="pre">dict.iterkeys()</span></code></a> to <a class="reference internal" href="stdtypes.html#dict.keys" title="dict.keys"><code class="xref py py-meth docutils literal notranslate"><span class="pre">dict.keys()</span></code></a>, and <a class="reference internal" href="stdtypes.html#dict.itervalues" title="dict.itervalues"><code class="xref py py-meth docutils literal notranslate"><span class="pre">dict.itervalues()</span></code></a> to <a class="reference internal" href="stdtypes.html#dict.values" title="dict.values"><code class="xref py py-meth docutils literal notranslate"><span class="pre">dict.values()</span></code></a>. Similarly, <a class="reference internal" href="stdtypes.html#dict.viewitems" title="dict.viewitems"><code class="xref py py-meth docutils literal notranslate"><span class="pre">dict.viewitems()</span></code></a>, <a class="reference internal" href="stdtypes.html#dict.viewkeys" title="dict.viewkeys"><code class="xref py py-meth docutils literal notranslate"><span class="pre">dict.viewkeys()</span></code></a> and <a class="reference internal" href="stdtypes.html#dict.viewvalues" title="dict.viewvalues"><code class="xref py py-meth docutils literal notranslate"><span class="pre">dict.viewvalues()</span></code></a> are converted respectively to <a class="reference internal" href="stdtypes.html#dict.items" title="dict.items"><code class="xref py py-meth docutils literal notranslate"><span class="pre">dict.items()</span></code></a>, <a class="reference internal" href="stdtypes.html#dict.keys" title="dict.keys"><code class="xref py py-meth docutils literal notranslate"><span class="pre">dict.keys()</span></code></a> and <a class="reference internal" href="stdtypes.html#dict.values" title="dict.values"><code class="xref py py-meth docutils literal notranslate"><span class="pre">dict.values()</span></code></a>. It also wraps existing usages of <a class="reference internal" href="stdtypes.html#dict.items" title="dict.items"><code class="xref py py-meth docutils literal notranslate"><span class="pre">dict.items()</span></code></a>, <a class="reference internal" href="stdtypes.html#dict.keys" title="dict.keys"><code class="xref py py-meth docutils literal notranslate"><span class="pre">dict.keys()</span></code></a>, and <a class="reference internal" href="stdtypes.html#dict.values" title="dict.values"><code class="xref py py-meth docutils literal notranslate"><span class="pre">dict.values()</span></code></a> in a call to <code class="xref py py-class docutils literal notranslate"><span class="pre">list</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-except"> <code class="descname">except</code><a class="headerlink" href="#2to3fixer-except" title="Permalink to this definition">¶</a></dt> <dd><p>Converts <code class="docutils literal notranslate"><span class="pre">except</span> <span class="pre">X,</span> <span class="pre">T</span></code> to <code class="docutils literal notranslate"><span class="pre">except</span> <span class="pre">X</span> <span class="pre">as</span> <span class="pre">T</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-exec"> <code class="descname">exec</code><a class="headerlink" href="#2to3fixer-exec" title="Permalink to this definition">¶</a></dt> <dd><p>Converts the <a class="reference internal" href="../reference/simple_stmts.html#exec"><code class="xref std std-keyword docutils literal notranslate"><span class="pre">exec</span></code></a> statement to the <code class="xref py py-func docutils literal notranslate"><span class="pre">exec()</span></code> function.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-execfile"> <code class="descname">execfile</code><a class="headerlink" href="#2to3fixer-execfile" title="Permalink to this definition">¶</a></dt> <dd><p>Removes usage of <a class="reference internal" href="functions.html#execfile" title="execfile"><code class="xref py py-func docutils literal notranslate"><span class="pre">execfile()</span></code></a>. The argument to <a class="reference internal" href="functions.html#execfile" title="execfile"><code class="xref py py-func docutils literal notranslate"><span class="pre">execfile()</span></code></a> is wrapped in calls to <a class="reference internal" href="functions.html#open" title="open"><code class="xref py py-func docutils literal notranslate"><span class="pre">open()</span></code></a>, <a class="reference internal" href="functions.html#compile" title="compile"><code class="xref py py-func docutils literal notranslate"><span class="pre">compile()</span></code></a>, and <code class="xref py py-func docutils literal notranslate"><span class="pre">exec()</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-exitfunc"> <code class="descname">exitfunc</code><a class="headerlink" href="#2to3fixer-exitfunc" title="Permalink to this definition">¶</a></dt> <dd><p>Changes assignment of <a class="reference internal" href="sys.html#sys.exitfunc" title="sys.exitfunc"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.exitfunc</span></code></a> to use of the <a class="reference internal" href="atexit.html#module-atexit" title="atexit: Register and execute cleanup functions."><code class="xref py py-mod docutils literal notranslate"><span class="pre">atexit</span></code></a> module.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-filter"> <code class="descname">filter</code><a class="headerlink" href="#2to3fixer-filter" title="Permalink to this definition">¶</a></dt> <dd><p>Wraps <a class="reference internal" href="functions.html#filter" title="filter"><code class="xref py py-func docutils literal notranslate"><span class="pre">filter()</span></code></a> usage in a <code class="xref py py-class docutils literal notranslate"><span class="pre">list</span></code> call.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-funcattrs"> <code class="descname">funcattrs</code><a class="headerlink" href="#2to3fixer-funcattrs" title="Permalink to this definition">¶</a></dt> <dd><p>Fixes function attributes that have been renamed. For example, <code class="docutils literal notranslate"><span class="pre">my_function.func_closure</span></code> is converted to <code class="docutils literal notranslate"><span class="pre">my_function.__closure__</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-future"> <code class="descname">future</code><a class="headerlink" href="#2to3fixer-future" title="Permalink to this definition">¶</a></dt> <dd><p>Removes <code class="docutils literal notranslate"><span class="pre">from</span> <span class="pre">__future__</span> <span class="pre">import</span> <span class="pre">new_feature</span></code> statements.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-getcwdu"> <code class="descname">getcwdu</code><a class="headerlink" href="#2to3fixer-getcwdu" title="Permalink to this definition">¶</a></dt> <dd><p>Renames <a class="reference internal" href="os.html#os.getcwdu" title="os.getcwdu"><code class="xref py py-func docutils literal notranslate"><span class="pre">os.getcwdu()</span></code></a> to <a class="reference internal" href="os.html#os.getcwd" title="os.getcwd"><code class="xref py py-func docutils literal notranslate"><span class="pre">os.getcwd()</span></code></a>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-has_key"> <code class="descname">has_key</code><a class="headerlink" href="#2to3fixer-has_key" title="Permalink to this definition">¶</a></dt> <dd><p>Changes <code class="docutils literal notranslate"><span class="pre">dict.has_key(key)</span></code> to <code class="docutils literal notranslate"><span class="pre">key</span> <span class="pre">in</span> <span class="pre">dict</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-idioms"> <code class="descname">idioms</code><a class="headerlink" href="#2to3fixer-idioms" title="Permalink to this definition">¶</a></dt> <dd><p>This optional fixer performs several transformations that make Python code more idiomatic. Type comparisons like <code class="docutils literal notranslate"><span class="pre">type(x)</span> <span class="pre">is</span> <span class="pre">SomeClass</span></code> and <code class="docutils literal notranslate"><span class="pre">type(x)</span> <span class="pre">==</span> <span class="pre">SomeClass</span></code> are converted to <code class="docutils literal notranslate"><span class="pre">isinstance(x,</span> <span class="pre">SomeClass)</span></code>. <code class="docutils literal notranslate"><span class="pre">while</span> <span class="pre">1</span></code> becomes <code class="docutils literal notranslate"><span class="pre">while</span> <span class="pre">True</span></code>. This fixer also tries to make use of <a class="reference internal" href="functions.html#sorted" title="sorted"><code class="xref py py-func docutils literal notranslate"><span class="pre">sorted()</span></code></a> in appropriate places. For example, this block</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">L</span> <span class="o">=</span> <span class="nb">list</span><span class="p">(</span><span class="n">some_iterable</span><span class="p">)</span> <span class="n">L</span><span class="o">.</span><span class="n">sort</span><span class="p">()</span> </pre></div> </div> <p>is changed to</p> <div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">L</span> <span class="o">=</span> <span class="nb">sorted</span><span class="p">(</span><span class="n">some_iterable</span><span class="p">)</span> </pre></div> </div> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-import"> <code class="descname">import</code><a class="headerlink" href="#2to3fixer-import" title="Permalink to this definition">¶</a></dt> <dd><p>Detects sibling imports and converts them to relative imports.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-imports"> <code class="descname">imports</code><a class="headerlink" href="#2to3fixer-imports" title="Permalink to this definition">¶</a></dt> <dd><p>Handles module renames in the standard library.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-imports2"> <code class="descname">imports2</code><a class="headerlink" href="#2to3fixer-imports2" title="Permalink to this definition">¶</a></dt> <dd><p>Handles other modules renames in the standard library. It is separate from the <a class="reference internal" href="#2to3fixer-imports"><code class="xref std std-2to3fixer docutils literal notranslate"><span class="pre">imports</span></code></a> fixer only because of technical limitations.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-input"> <code class="descname">input</code><a class="headerlink" href="#2to3fixer-input" title="Permalink to this definition">¶</a></dt> <dd><p>Converts <code class="docutils literal notranslate"><span class="pre">input(prompt)</span></code> to <code class="docutils literal notranslate"><span class="pre">eval(input(prompt))</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-intern"> <code class="descname">intern</code><a class="headerlink" href="#2to3fixer-intern" title="Permalink to this definition">¶</a></dt> <dd><p>Converts <a class="reference internal" href="functions.html#intern" title="intern"><code class="xref py py-func docutils literal notranslate"><span class="pre">intern()</span></code></a> to <code class="xref py py-func docutils literal notranslate"><span class="pre">sys.intern()</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-isinstance"> <code class="descname">isinstance</code><a class="headerlink" href="#2to3fixer-isinstance" title="Permalink to this definition">¶</a></dt> <dd><p>Fixes duplicate types in the second argument of <a class="reference internal" href="functions.html#isinstance" title="isinstance"><code class="xref py py-func docutils literal notranslate"><span class="pre">isinstance()</span></code></a>. For example, <code class="docutils literal notranslate"><span class="pre">isinstance(x,</span> <span class="pre">(int,</span> <span class="pre">int))</span></code> is converted to <code class="docutils literal notranslate"><span class="pre">isinstance(x,</span> <span class="pre">(int))</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-itertools_imports"> <code class="descname">itertools_imports</code><a class="headerlink" href="#2to3fixer-itertools_imports" title="Permalink to this definition">¶</a></dt> <dd><p>Removes imports of <a class="reference internal" href="itertools.html#itertools.ifilter" title="itertools.ifilter"><code class="xref py py-func docutils literal notranslate"><span class="pre">itertools.ifilter()</span></code></a>, <a class="reference internal" href="itertools.html#itertools.izip" title="itertools.izip"><code class="xref py py-func docutils literal notranslate"><span class="pre">itertools.izip()</span></code></a>, and <a class="reference internal" href="itertools.html#itertools.imap" title="itertools.imap"><code class="xref py py-func docutils literal notranslate"><span class="pre">itertools.imap()</span></code></a>. Imports of <a class="reference internal" href="itertools.html#itertools.ifilterfalse" title="itertools.ifilterfalse"><code class="xref py py-func docutils literal notranslate"><span class="pre">itertools.ifilterfalse()</span></code></a> are also changed to <code class="xref py py-func docutils literal notranslate"><span class="pre">itertools.filterfalse()</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-itertools"> <code class="descname">itertools</code><a class="headerlink" href="#2to3fixer-itertools" title="Permalink to this definition">¶</a></dt> <dd><p>Changes usage of <a class="reference internal" href="itertools.html#itertools.ifilter" title="itertools.ifilter"><code class="xref py py-func docutils literal notranslate"><span class="pre">itertools.ifilter()</span></code></a>, <a class="reference internal" href="itertools.html#itertools.izip" title="itertools.izip"><code class="xref py py-func docutils literal notranslate"><span class="pre">itertools.izip()</span></code></a>, and <a class="reference internal" href="itertools.html#itertools.imap" title="itertools.imap"><code class="xref py py-func docutils literal notranslate"><span class="pre">itertools.imap()</span></code></a> to their built-in equivalents. <a class="reference internal" href="itertools.html#itertools.ifilterfalse" title="itertools.ifilterfalse"><code class="xref py py-func docutils literal notranslate"><span class="pre">itertools.ifilterfalse()</span></code></a> is changed to <code class="xref py py-func docutils literal notranslate"><span class="pre">itertools.filterfalse()</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-long"> <code class="descname">long</code><a class="headerlink" href="#2to3fixer-long" title="Permalink to this definition">¶</a></dt> <dd><p>Renames <a class="reference internal" href="functions.html#long" title="long"><code class="xref py py-class docutils literal notranslate"><span class="pre">long</span></code></a> to <a class="reference internal" href="functions.html#int" title="int"><code class="xref py py-class docutils literal notranslate"><span class="pre">int</span></code></a>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-map"> <code class="descname">map</code><a class="headerlink" href="#2to3fixer-map" title="Permalink to this definition">¶</a></dt> <dd><p>Wraps <a class="reference internal" href="functions.html#map" title="map"><code class="xref py py-func docutils literal notranslate"><span class="pre">map()</span></code></a> in a <code class="xref py py-class docutils literal notranslate"><span class="pre">list</span></code> call. It also changes <code class="docutils literal notranslate"><span class="pre">map(None,</span> <span class="pre">x)</span></code> to <code class="docutils literal notranslate"><span class="pre">list(x)</span></code>. Using <code class="docutils literal notranslate"><span class="pre">from</span> <span class="pre">future_builtins</span> <span class="pre">import</span> <span class="pre">map</span></code> disables this fixer.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-metaclass"> <code class="descname">metaclass</code><a class="headerlink" href="#2to3fixer-metaclass" title="Permalink to this definition">¶</a></dt> <dd><p>Converts the old metaclass syntax (<code class="docutils literal notranslate"><span class="pre">__metaclass__</span> <span class="pre">=</span> <span class="pre">Meta</span></code> in the class body) to the new (<code class="docutils literal notranslate"><span class="pre">class</span> <span class="pre">X(metaclass=Meta)</span></code>).</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-methodattrs"> <code class="descname">methodattrs</code><a class="headerlink" href="#2to3fixer-methodattrs" title="Permalink to this definition">¶</a></dt> <dd><p>Fixes old method attribute names. For example, <code class="docutils literal notranslate"><span class="pre">meth.im_func</span></code> is converted to <code class="docutils literal notranslate"><span class="pre">meth.__func__</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-ne"> <code class="descname">ne</code><a class="headerlink" href="#2to3fixer-ne" title="Permalink to this definition">¶</a></dt> <dd><p>Converts the old not-equal syntax, <code class="docutils literal notranslate"><span class="pre"><></span></code>, to <code class="docutils literal notranslate"><span class="pre">!=</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-next"> <code class="descname">next</code><a class="headerlink" href="#2to3fixer-next" title="Permalink to this definition">¶</a></dt> <dd><p>Converts the use of iterator’s <a class="reference internal" href="stdtypes.html#iterator.next" title="iterator.next"><code class="xref py py-meth docutils literal notranslate"><span class="pre">next()</span></code></a> methods to the <a class="reference internal" href="functions.html#next" title="next"><code class="xref py py-func docutils literal notranslate"><span class="pre">next()</span></code></a> function. It also renames <a class="reference internal" href="stdtypes.html#iterator.next" title="iterator.next"><code class="xref py py-meth docutils literal notranslate"><span class="pre">next()</span></code></a> methods to <code class="xref py py-meth docutils literal notranslate"><span class="pre">__next__()</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-nonzero"> <code class="descname">nonzero</code><a class="headerlink" href="#2to3fixer-nonzero" title="Permalink to this definition">¶</a></dt> <dd><p>Renames <a class="reference internal" href="../reference/datamodel.html#object.__nonzero__" title="object.__nonzero__"><code class="xref py py-meth docutils literal notranslate"><span class="pre">__nonzero__()</span></code></a> to <code class="xref py py-meth docutils literal notranslate"><span class="pre">__bool__()</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-numliterals"> <code class="descname">numliterals</code><a class="headerlink" href="#2to3fixer-numliterals" title="Permalink to this definition">¶</a></dt> <dd><p>Converts octal literals into the new syntax.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-paren"> <code class="descname">paren</code><a class="headerlink" href="#2to3fixer-paren" title="Permalink to this definition">¶</a></dt> <dd><p>Add extra parenthesis where they are required in list comprehensions. For example, <code class="docutils literal notranslate"><span class="pre">[x</span> <span class="pre">for</span> <span class="pre">x</span> <span class="pre">in</span> <span class="pre">1,</span> <span class="pre">2]</span></code> becomes <code class="docutils literal notranslate"><span class="pre">[x</span> <span class="pre">for</span> <span class="pre">x</span> <span class="pre">in</span> <span class="pre">(1,</span> <span class="pre">2)]</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-print"> <code class="descname">print</code><a class="headerlink" href="#2to3fixer-print" title="Permalink to this definition">¶</a></dt> <dd><p>Converts the <a class="reference internal" href="../reference/simple_stmts.html#print"><code class="xref std std-keyword docutils literal notranslate"><span class="pre">print</span></code></a> statement to the <a class="reference internal" href="functions.html#print" title="print"><code class="xref py py-func docutils literal notranslate"><span class="pre">print()</span></code></a> function.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-raise"> <code class="descname">raise</code><a class="headerlink" href="#2to3fixer-raise" title="Permalink to this definition">¶</a></dt> <dd><p>Converts <code class="docutils literal notranslate"><span class="pre">raise</span> <span class="pre">E,</span> <span class="pre">V</span></code> to <code class="docutils literal notranslate"><span class="pre">raise</span> <span class="pre">E(V)</span></code>, and <code class="docutils literal notranslate"><span class="pre">raise</span> <span class="pre">E,</span> <span class="pre">V,</span> <span class="pre">T</span></code> to <code class="docutils literal notranslate"><span class="pre">raise</span> <span class="pre">E(V).with_traceback(T)</span></code>. If <code class="docutils literal notranslate"><span class="pre">E</span></code> is a tuple, the translation will be incorrect because substituting tuples for exceptions has been removed in Python 3.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-raw_input"> <code class="descname">raw_input</code><a class="headerlink" href="#2to3fixer-raw_input" title="Permalink to this definition">¶</a></dt> <dd><p>Converts <a class="reference internal" href="functions.html#raw_input" title="raw_input"><code class="xref py py-func docutils literal notranslate"><span class="pre">raw_input()</span></code></a> to <a class="reference internal" href="functions.html#input" title="input"><code class="xref py py-func docutils literal notranslate"><span class="pre">input()</span></code></a>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-reduce"> <code class="descname">reduce</code><a class="headerlink" href="#2to3fixer-reduce" title="Permalink to this definition">¶</a></dt> <dd><p>Handles the move of <a class="reference internal" href="functions.html#reduce" title="reduce"><code class="xref py py-func docutils literal notranslate"><span class="pre">reduce()</span></code></a> to <a class="reference internal" href="functools.html#functools.reduce" title="functools.reduce"><code class="xref py py-func docutils literal notranslate"><span class="pre">functools.reduce()</span></code></a>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-renames"> <code class="descname">renames</code><a class="headerlink" href="#2to3fixer-renames" title="Permalink to this definition">¶</a></dt> <dd><p>Changes <a class="reference internal" href="sys.html#sys.maxint" title="sys.maxint"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.maxint</span></code></a> to <a class="reference internal" href="sys.html#sys.maxsize" title="sys.maxsize"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.maxsize</span></code></a>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-repr"> <code class="descname">repr</code><a class="headerlink" href="#2to3fixer-repr" title="Permalink to this definition">¶</a></dt> <dd><p>Replaces backtick repr with the <a class="reference internal" href="functions.html#repr" title="repr"><code class="xref py py-func docutils literal notranslate"><span class="pre">repr()</span></code></a> function.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-set_literal"> <code class="descname">set_literal</code><a class="headerlink" href="#2to3fixer-set_literal" title="Permalink to this definition">¶</a></dt> <dd><p>Replaces use of the <a class="reference internal" href="stdtypes.html#set" title="set"><code class="xref py py-class docutils literal notranslate"><span class="pre">set</span></code></a> constructor with set literals. This fixer is optional.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-standarderror"> <code class="descname">standarderror</code><a class="headerlink" href="#2to3fixer-standarderror" title="Permalink to this definition">¶</a></dt> <dd><p>Renames <a class="reference internal" href="exceptions.html#exceptions.StandardError" title="exceptions.StandardError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">StandardError</span></code></a> to <a class="reference internal" href="exceptions.html#exceptions.Exception" title="exceptions.Exception"><code class="xref py py-exc docutils literal notranslate"><span class="pre">Exception</span></code></a>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-sys_exc"> <code class="descname">sys_exc</code><a class="headerlink" href="#2to3fixer-sys_exc" title="Permalink to this definition">¶</a></dt> <dd><p>Changes the deprecated <a class="reference internal" href="sys.html#sys.exc_value" title="sys.exc_value"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.exc_value</span></code></a>, <a class="reference internal" href="sys.html#sys.exc_type" title="sys.exc_type"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.exc_type</span></code></a>, <a class="reference internal" href="sys.html#sys.exc_traceback" title="sys.exc_traceback"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.exc_traceback</span></code></a> to use <a class="reference internal" href="sys.html#sys.exc_info" title="sys.exc_info"><code class="xref py py-func docutils literal notranslate"><span class="pre">sys.exc_info()</span></code></a>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-throw"> <code class="descname">throw</code><a class="headerlink" href="#2to3fixer-throw" title="Permalink to this definition">¶</a></dt> <dd><p>Fixes the API change in generator’s <code class="xref py py-meth docutils literal notranslate"><span class="pre">throw()</span></code> method.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-tuple_params"> <code class="descname">tuple_params</code><a class="headerlink" href="#2to3fixer-tuple_params" title="Permalink to this definition">¶</a></dt> <dd><p>Removes implicit tuple parameter unpacking. This fixer inserts temporary variables.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-types"> <code class="descname">types</code><a class="headerlink" href="#2to3fixer-types" title="Permalink to this definition">¶</a></dt> <dd><p>Fixes code broken from the removal of some members in the <a class="reference internal" href="types.html#module-types" title="types: Names for built-in types."><code class="xref py py-mod docutils literal notranslate"><span class="pre">types</span></code></a> module.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-unicode"> <code class="descname">unicode</code><a class="headerlink" href="#2to3fixer-unicode" title="Permalink to this definition">¶</a></dt> <dd><p>Renames <a class="reference internal" href="functions.html#unicode" title="unicode"><code class="xref py py-class docutils literal notranslate"><span class="pre">unicode</span></code></a> to <a class="reference internal" href="functions.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-urllib"> <code class="descname">urllib</code><a class="headerlink" href="#2to3fixer-urllib" title="Permalink to this definition">¶</a></dt> <dd><p>Handles the rename of <a class="reference internal" href="urllib.html#module-urllib" title="urllib: Open an arbitrary network resource by URL (requires sockets)."><code class="xref py py-mod docutils literal notranslate"><span class="pre">urllib</span></code></a> and <a class="reference internal" href="urllib2.html#module-urllib2" title="urllib2: Next generation URL opening library."><code class="xref py py-mod docutils literal notranslate"><span class="pre">urllib2</span></code></a> to the <a class="reference internal" href="urllib.html#module-urllib" title="urllib: Open an arbitrary network resource by URL (requires sockets)."><code class="xref py py-mod docutils literal notranslate"><span class="pre">urllib</span></code></a> package.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-ws_comma"> <code class="descname">ws_comma</code><a class="headerlink" href="#2to3fixer-ws_comma" title="Permalink to this definition">¶</a></dt> <dd><p>Removes excess whitespace from comma separated items. This fixer is optional.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-xrange"> <code class="descname">xrange</code><a class="headerlink" href="#2to3fixer-xrange" title="Permalink to this definition">¶</a></dt> <dd><p>Renames <a class="reference internal" href="functions.html#xrange" title="xrange"><code class="xref py py-func docutils literal notranslate"><span class="pre">xrange()</span></code></a> to <a class="reference internal" href="functions.html#range" title="range"><code class="xref py py-func docutils literal notranslate"><span class="pre">range()</span></code></a> and wraps existing <a class="reference internal" href="functions.html#range" title="range"><code class="xref py py-func docutils literal notranslate"><span class="pre">range()</span></code></a> calls with <code class="xref py py-class docutils literal notranslate"><span class="pre">list</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-xreadlines"> <code class="descname">xreadlines</code><a class="headerlink" href="#2to3fixer-xreadlines" title="Permalink to this definition">¶</a></dt> <dd><p>Changes <code class="docutils literal notranslate"><span class="pre">for</span> <span class="pre">x</span> <span class="pre">in</span> <span class="pre">file.xreadlines()</span></code> to <code class="docutils literal notranslate"><span class="pre">for</span> <span class="pre">x</span> <span class="pre">in</span> <span class="pre">file</span></code>.</p> </dd></dl> <dl class="2to3fixer"> <dt id="2to3fixer-zip"> <code class="descname">zip</code><a class="headerlink" href="#2to3fixer-zip" title="Permalink to this definition">¶</a></dt> <dd><p>Wraps <a class="reference internal" href="functions.html#zip" title="zip"><code class="xref py py-func docutils literal notranslate"><span class="pre">zip()</span></code></a> usage in a <code class="xref py py-class docutils literal notranslate"><span class="pre">list</span></code> call. This is disabled when <code class="docutils literal notranslate"><span class="pre">from</span> <span class="pre">future_builtins</span> <span class="pre">import</span> <span class="pre">zip</span></code> appears.</p> </dd></dl> </div> <div class="section" id="module-lib2to3"> <span id="lib2to3-2to3-s-library"></span><h2>25.4.3. <a class="reference internal" href="#module-lib2to3" title="lib2to3: the 2to3 library"><code class="xref py py-mod docutils literal notranslate"><span class="pre">lib2to3</span></code></a> - 2to3’s library<a class="headerlink" href="#module-lib2to3" title="Permalink to this headline">¶</a></h2> <div class="admonition note"> <p class="first admonition-title">Note</p> <p class="last">The <a class="reference internal" href="#module-lib2to3" title="lib2to3: the 2to3 library"><code class="xref py py-mod docutils literal notranslate"><span class="pre">lib2to3</span></code></a> API should be considered unstable and may change drastically in the future.</p> </div> </div> </div> </div> </div> </div> <div class="sphinxsidebar" role="navigation" aria-label="main navigation"> <div class="sphinxsidebarwrapper"> <h3><a href="../contents.html">Table of Contents</a></h3> <ul> <li><a class="reference internal" href="#">25.4. 2to3 - Automated Python 2 to 3 code translation</a><ul> <li><a class="reference internal" href="#using-2to3">25.4.1. Using 2to3</a></li> <li><a class="reference internal" href="#fixers">25.4.2. Fixers</a></li> <li><a class="reference internal" href="#module-lib2to3">25.4.3. <code class="docutils literal notranslate"><span class="pre">lib2to3</span></code> - 2to3’s library</a></li> </ul> </li> </ul> <h4>Previous topic</h4> <p class="topless"><a href="unittest.html" title="previous chapter">25.3. <code class="docutils literal notranslate"><span class="pre">unittest</span></code> — Unit testing framework</a></p> <h4>Next topic</h4> <p class="topless"><a href="test.html" title="next chapter">25.5. <code class="docutils literal notranslate"><span class="pre">test</span></code> — Regression tests package for Python</a></p> <div role="note" aria-label="source link"> <h3>This Page</h3> <ul class="this-page-menu"> <li><a href="../_sources/library/2to3.rst.txt" rel="nofollow">Show Source</a></li> </ul> </div> <div id="searchbox" style="display: none" role="search"> <h3>Quick search</h3> <div class="searchformwrapper"> <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> </div> </div> <script type="text/javascript">$('#searchbox').show(0);</script> </div> </div> <div class="clearer"></div> </div> <div class="related" role="navigation" aria-label="related navigation"> <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="test.html" title="25.5. test — Regression tests package for Python" >next</a> |</li> <li class="right" > <a href="unittest.html" title="25.3. unittest — Unit testing framework" >previous</a> |</li> <li><img src="../_static/py.png" alt="" style="vertical-align: middle; margin-top: -1px"/></li> <li><a href="https://www.python.org/">Python</a> »</li> <li> <a href="../index.html">Python 2.7.18 documentation</a> » </li> <li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> »</li> <li class="nav-item nav-item-2"><a href="development.html" >25. 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