http://chestnutheng.github.io/tags/prof/ Recent content in Prof on 子恒的博客 Hugo zh-CN Tue, 09 Aug 2016 13:04:35 +0800 http://chestnutheng.github.io/python_profile/ Tue, 09 Aug 2016 13:04:30 +0800 http://chestnutheng.github.io/python_profile/ <h2 id="时间分析">时间分析</h2> <h3 id="time-命令">time 命令</h3> <p>用*nix自带的系统命令</p> <div class="highlight"><div class="chroma"> <table class="lntable"><tr><td class="lntd"> <pre tabindex="0" class="chroma"><code><span class="lnt">1 </span><span class="lnt">2 </span><span class="lnt">3 </span><span class="lnt">4 </span><span class="lnt">5 </span></code></pre></td> <td class="lntd"> <pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback"><span class="line"><span class="cl">$ time python3 reg.py </span></span><span class="line"><span class="cl"> </span></span><span class="line"><span class="cl">real 0m1.617s </span></span><span class="line"><span class="cl">user 0m1.504s </span></span><span class="line"><span class="cl">sys 0m0.112s </span></span></code></pre></td></tr></table> </div> </div><p><code>sys</code> 系统调用时间<br> <code>user</code> 用户空间花费时间<br> <code>real</code> 实际时间<br> 如果<code>user + sys &lt; real</code> 说明时间被花费在IO上。</p> <h3 id="profile和cprofile">profile和cProfile</h3> <p>python自带了两个函数时间分析工具，cProfile和profile。cProfile是纯C写的，所以用起来快了很多。<br> 查看帮助:</p> <div class="highlight"><div class="chroma"> <table class="lntable"><tr><td class="lntd"> <pre tabindex="0" class="chroma"><code><span class="lnt">1 </span><span class="lnt">2 </span><span class="lnt">3 </span><span class="lnt">4 </span><span class="lnt">5 </span><span class="lnt">6 </span><span class="lnt">7 </span><span class="lnt">8 </span><span class="lnt">9 </span></code></pre></td> <td class="lntd"> <pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback"><span class="line"><span class="cl">$ python3 -m cProfile -h </span></span><span class="line"><span class="cl">Usage: cProfile.py [-o output_file_path] [-s sort] scriptfile [arg] ... </span></span><span class="line"><span class="cl"> </span></span><span class="line"><span class="cl">Options: </span></span><span class="line"><span class="cl"> -h, --help show this help message and exit </span></span><span class="line"><span class="cl"> -o OUTFILE, --outfile=OUTFILE </span></span><span class="line"><span class="cl"> Save stats to &lt;outfile&gt; </span></span><span class="line"><span class="cl"> -s SORT, --sort=SORT Sort order when printing to stdout, based on </span></span><span class="line"><span class="cl"> pstats.Stats class </span></span></code></pre></td></tr></table> </div> </div><p>-o 输出的文件只能给pstats.Stats类使用。<br> -s 是对结果按照关键字排序，关键字有<br> <code>calls, cumulative, file, line, module, name, nfl, pcalls, stdname, time</code></p>