<!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>Advanced usage — pep8 1.5.7 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: '1.5.7', 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="pep8 1.5.7 documentation" href="index.html" /> <link rel="next" title="pep8 API" href="api.html" /> <link rel="prev" title="Introduction" href="intro.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="api.html" title="pep8 API" accesskey="N">next</a> |</li> <li class="right" > <a href="intro.html" title="Introduction" accesskey="P">previous</a> |</li> <li><a href="index.html">pep8 1.5.7 documentation</a> »</li> </ul> </div> <div class="document"> <div class="documentwrapper"> <div class="bodywrapper"> <div class="body"> <div class="section" id="advanced-usage"> <h1>Advanced usage<a class="headerlink" href="#advanced-usage" title="Permalink to this headline">¶</a></h1> <div class="section" id="automated-tests"> <h2>Automated tests<a class="headerlink" href="#automated-tests" title="Permalink to this headline">¶</a></h2> <p>You can also execute <cite>pep8</cite> tests from Python code. For example, this can be highly useful for automated testing of coding style conformance in your project:</p> <div class="highlight-python"><div class="highlight"><pre><span class="kn">import</span> <span class="nn">unittest</span> <span class="kn">import</span> <span class="nn">pep8</span> <span class="k">class</span> <span class="nc">TestCodeFormat</span><span class="p">(</span><span class="n">unittest</span><span class="o">.</span><span class="n">TestCase</span><span class="p">):</span> <span class="k">def</span> <span class="nf">test_pep8_conformance</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span> <span class="sd">"""Test that we conform to PEP8."""</span> <span class="n">pep8style</span> <span class="o">=</span> <span class="n">pep8</span><span class="o">.</span><span class="n">StyleGuide</span><span class="p">(</span><span class="n">quiet</span><span class="o">=</span><span class="bp">True</span><span class="p">)</span> <span class="n">result</span> <span class="o">=</span> <span class="n">pep8style</span><span class="o">.</span><span class="n">check_files</span><span class="p">([</span><span class="s">'file1.py'</span><span class="p">,</span> <span class="s">'file2.py'</span><span class="p">])</span> <span class="bp">self</span><span class="o">.</span><span class="n">assertEqual</span><span class="p">(</span><span class="n">result</span><span class="o">.</span><span class="n">total_errors</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="s">"Found code style errors (and warnings)."</span><span class="p">)</span> </pre></div> </div> <p>If you are using <cite>nosetests</cite> for running tests, remove <cite>quiet=True</cite> since Nose suppresses stdout.</p> <p>There’s also a shortcut for checking a single file:</p> <div class="highlight-python"><div class="highlight"><pre><span class="kn">import</span> <span class="nn">pep8</span> <span class="n">fchecker</span> <span class="o">=</span> <span class="n">pep8</span><span class="o">.</span><span class="n">Checker</span><span class="p">(</span><span class="s">'testsuite/E27.py'</span><span class="p">,</span> <span class="n">show_source</span><span class="o">=</span><span class="bp">True</span><span class="p">)</span> <span class="n">file_errors</span> <span class="o">=</span> <span class="n">fchecker</span><span class="o">.</span><span class="n">check_all</span><span class="p">()</span> <span class="k">print</span><span class="p">(</span><span class="s">"Found </span><span class="si">%s</span><span class="s"> errors (and warnings)"</span> <span class="o">%</span> <span class="n">file_errors</span><span class="p">)</span> </pre></div> </div> </div> <div class="section" id="skip-file-header"> <h2>Skip file header<a class="headerlink" href="#skip-file-header" title="Permalink to this headline">¶</a></h2> <p>Another example is related to the <a class="reference external" href="https://github.com/jcrocholl/pep8/issues/143">feature request #143</a>: skip a number of lines at the beginning and the end of a file. This use case is easy to implement through a custom wrapper for the PEP 8 library:</p> <div class="highlight-python"><div class="highlight"><pre><span class="c">#!python</span> <span class="kn">import</span> <span class="nn">pep8</span> <span class="n">LINES_SLICE</span> <span class="o">=</span> <span class="nb">slice</span><span class="p">(</span><span class="mi">14</span><span class="p">,</span> <span class="o">-</span><span class="mi">20</span><span class="p">)</span> <span class="k">class</span> <span class="nc">PEP8</span><span class="p">(</span><span class="n">pep8</span><span class="o">.</span><span class="n">StyleGuide</span><span class="p">):</span> <span class="sd">"""This subclass of pep8.StyleGuide will skip the first and last lines</span> <span class="sd"> of each file."""</span> <span class="k">def</span> <span class="nf">input_file</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">filename</span><span class="p">,</span> <span class="n">lines</span><span class="o">=</span><span class="bp">None</span><span class="p">,</span> <span class="n">expected</span><span class="o">=</span><span class="bp">None</span><span class="p">,</span> <span class="n">line_offset</span><span class="o">=</span><span class="mi">0</span><span class="p">):</span> <span class="k">if</span> <span class="n">lines</span> <span class="ow">is</span> <span class="bp">None</span><span class="p">:</span> <span class="k">assert</span> <span class="n">line_offset</span> <span class="o">==</span> <span class="mi">0</span> <span class="n">line_offset</span> <span class="o">=</span> <span class="n">LINES_SLICE</span><span class="o">.</span><span class="n">start</span> <span class="ow">or</span> <span class="mi">0</span> <span class="n">lines</span> <span class="o">=</span> <span class="n">pep8</span><span class="o">.</span><span class="n">readlines</span><span class="p">(</span><span class="n">filename</span><span class="p">)[</span><span class="n">LINES_SLICE</span><span class="p">]</span> <span class="k">return</span> <span class="nb">super</span><span class="p">(</span><span class="n">PEP8</span><span class="p">,</span> <span class="bp">self</span><span class="p">)</span><span class="o">.</span><span class="n">input_file</span><span class="p">(</span> <span class="n">filename</span><span class="p">,</span> <span class="n">lines</span><span class="o">=</span><span class="n">lines</span><span class="p">,</span> <span class="n">expected</span><span class="o">=</span><span class="n">expected</span><span class="p">,</span> <span class="n">line_offset</span><span class="o">=</span><span class="n">line_offset</span><span class="p">)</span> <span class="k">if</span> <span class="n">__name__</span> <span class="o">==</span> <span class="s">'__main__'</span><span class="p">:</span> <span class="n">pep8style</span> <span class="o">=</span> <span class="n">PEP8</span><span class="p">(</span><span class="n">parse_argv</span><span class="o">=</span><span class="bp">True</span><span class="p">,</span> <span class="n">config_file</span><span class="o">=</span><span class="bp">True</span><span class="p">)</span> <span class="n">report</span> <span class="o">=</span> <span class="n">pep8style</span><span class="o">.</span><span class="n">check_files</span><span class="p">()</span> <span class="k">if</span> <span class="n">report</span><span class="o">.</span><span class="n">total_errors</span><span class="p">:</span> <span class="k">raise</span> <span class="ne">SystemExit</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span> </pre></div> </div> <p>This module declares a lines’ window which skips 14 lines at the beginning and 20 lines at the end. If there’s no line to skip at the end, it could be changed with <tt class="docutils literal"><span class="pre">LINES_SLICE</span> <span class="pre">=</span> <span class="pre">slice(14,</span> <span class="pre">None)</span></tt> for example.</p> <p>You can save it in a file and use it with the same options as the original <tt class="docutils literal"><span class="pre">pep8</span></tt>.</p> </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="#">Advanced usage</a><ul> <li><a class="reference internal" href="#automated-tests">Automated tests</a></li> <li><a class="reference internal" href="#skip-file-header">Skip file header</a></li> </ul> </li> </ul> <h4>Previous topic</h4> <p class="topless"><a href="intro.html" title="previous chapter">Introduction</a></p> <h4>Next topic</h4> <p class="topless"><a href="api.html" title="next chapter">pep8 API</a></p> <h3>This Page</h3> <ul class="this-page-menu"> <li><a href="_sources/advanced.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="api.html" title="pep8 API" >next</a> |</li> <li class="right" > <a href="intro.html" title="Introduction" >previous</a> |</li> <li><a href="index.html">pep8 1.5.7 documentation</a> »</li> </ul> </div> <div class="footer"> © Copyright 2012-2013, Florent Xicluna. 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