擅长：python、mysql、java
<p>您可以对<code>groupby</code>对象调用<code>rank</code>，并传递参数<code>method='first'</code>：</p>
<pre><code>In [61]:
df['domainId'] = df.groupby('orgid')['orgid'].rank(method='first')
df
Out[61]:
domain orgid domainId
0 csyunshu.com 108299 1
1 dshu.com 108299 2
2 bbbdshu.com 108299 3
3 cwakwakmrg.com 121303 1
4 ckonkatsunet.com 121303 2
</code></pre>
<p>如果要覆盖列，可以执行以下操作：</p>
<pre><code>df['domain'] = df.groupby('orgid')['orgid'].rank(method='first')
</code></pre>
