擅长:python、mysql、java
<p>只要值是datetime(NaT是缺少的值,而不是字符串),您就可以使用:</p>
<pre><code>df['no_calv'] = df.notna().sum(axis = 1)
</code></pre>
<p>要获得:</p>
<pre><code>id calv1 calv2 calv3 calv4 no_calv
1 2006-08-29 2007-08-29 2008-08-29 2009-08-29 4
2 NaT NaT NaT NaT 0
3 2006-08-29 NaT NaT NaT 1
4 2006-08-29 2007-08-29 2010-08-29 NaT 3
5 2006-08-29 2013-08-29 NaT NaT 2
</code></pre>
<p>它会检查是否存在未丢失的值,并沿行(轴=1)求和</p>