擅长:python、mysql、java
<P>可以考虑在聚合之前放弃null:</p>
<pre><code> (
df.dropna()
.groupby("Person")
.agg(CountJob=("Job", "count"), JobDetails=("Job", set))
.assign(JobDetails=lambda df: df.JobDetails.str.join(","))
)
CountJob JobDetails
Person
Cathy 4 j1,j3,j5
Mark 1 j2
Steve 1 j4
</code></pre>