擅长:python、mysql、java
<h3><code>mask</code>和<code>bfill</code></h3>
<pre><code>df[df['first_name'].mask(df['first_name'] != 'Alex').bfill().notna()]
first_name
0 Andy
1 Josh
2 Mark
3 Tim
4 Alex
5 Andy
6 Josh
7 Mark
8 Tim
9 Alex
</code></pre>
<hr/>
<h2><code>cumsum</code>和<code>idxmax</code></h2>
<pre><code>df.loc[:(df['first_name'] == 'Alex').cumsum().idxmax()]
first_name
0 Andy
1 Josh
2 Mark
3 Tim
4 Alex
5 Andy
6 Josh
7 Mark
8 Tim
9 Alex
</code></pre>
<hr/>
<h2><code>cumsum</code>和<code>max</code></h2>
<pre><code>u = (df['first_name'] == 'Alex').shift().cumsum()
df[u < u.max()]
first_name
1 Josh
2 Mark
3 Tim
4 Alex
5 Andy
6 Josh
7 Mark
8 Tim
9 Alex
</code></pre>