擅长:python、mysql、java
<p>可以使用<a href="https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.transform.html" rel="nofollow noreferrer">^{<cd1>}</a>和<a href="https://pandas.pydata.org/pandas-docs/version/0.23.4/generated/pandas.factorize.html" rel="nofollow noreferrer">^{<cd2>}</a>:</p>
<pre><code>df['counter'] = df.groupby(['id'])['id2'].transform(lambda x: pd.factorize(x)[0]).add(1)
id id2 val counter
0 a red apple 1
1 a red orange 1
2 b blue fish 1
3 c violet beef 1
4 a yellow banana 2
5 a black pork 3
</code></pre>