擅长:python、mysql、java
<p>假设你有熊猫,像这样的东西应该工作。你知道吗</p>
<pre><code>trial['newAgg'] = trial.groupby(['identifier'])['aggregation'].apply(lambda x: (x + '-').cumsum().str.strip())
</code></pre>
<p>*编辑:*根据您的代码片段,这应该适用于<code>trial["newAgg"]</code>无需编写<code>else</code></p>
<pre><code>for index, row in trial.iterrows():
if row.identifier == row.newId:
trial["newAgg"] = trial.groupby(['identifier'])['aggregation'].apply(lambda x: (x + '-').cumsum().str.strip())
trial["newAgg"] = [i[ : -1] for i in list(trial['newAgg'])]
</code></pre>