https://blog.witd.in/tags/python/ Recent content in Python on 备忘 Hugo -- gohugo.io en-us kongfei605@gmail.com (kongfei) kongfei605@gmail.com (kongfei) (c) 2022 witd. All rights reserved Sun, 31 Jan 2016 15:19:27 +0800 https://blog.witd.in/2016/01/31/pandas-sum%E5%87%BD%E6%95%B0%E5%B0%8F%E7%BB%93/ Sun, 31 Jan 2016 15:19:27 +0800 kongfei605@gmail.com (kongfei) https://blog.witd.in/2016/01/31/pandas-sum%E5%87%BD%E6%95%B0%E5%B0%8F%E7%BB%93/ <p><a href="http://pandas.pydata.org/pandas-docs/version/0.17.1/generated/pandas.DataFrame.sum.html">sum()函数文档</a>中说sum的作用是Return the sum of the values for the requested axis ，即返回指定栏或列的值的和。</p> <p>函数有4个有名参数， <code>axis=None, skipna=None, level=None, numeric_only=None, **kwargs</code> 。 不指定任何参数时即给axis赋值。</p> <p>当sum(1)时是求行的和，当sum(0)时是求列的和。理解这个用法时参考了这个链接：<a href="http://blog.mathandpencil.com/column-and-row-sums/">http://blog.mathandpencil.com/column-and-row-sums/</a>  </p> <p>If you want to do a row sum in pandas, given the dataframe df:</p> <pre><code>python df.sum(axis=1) </code></pre> <p>and a column sum:</p> <pre><code>python df.sum(axis=0) </code></pre> <p></p> https://blog.witd.in/2014/10/04/python%E7%A9%BA%E6%A0%BC%E4%B8%8Etab%E8%BD%AC%E6%8D%A2/ Sat, 04 Oct 2014 15:51:01 +0800 kongfei605@gmail.com (kongfei) https://blog.witd.in/2014/10/04/python%E7%A9%BA%E6%A0%BC%E4%B8%8Etab%E8%BD%AC%E6%8D%A2/ <p>vim中</p> <p>TAB替换为空格：</p> <pre><code>:set ts=4 :set expandtab :%retab! </code></pre> <p>空格替换为TAB：</p> <pre><code>:set ts=4 :set noexpandtab :%retab! </code></pre>