python - Pandas:复杂的聚合问题

Question

我有这个Dataframe

In [4]: df = pd.DataFrame({'person':[1,1,2,2,3,3,3, 4], 'area':['A','B','A','A',
'C','C','C','C'], 'job type':['politics', 'expert', 'politics', 'politics', 'law
yer','judge', 'judge', 'lawyer']})

In [5]: df
Out[5]:
  area  job type  person
0    A  politics       1
1    B    expert       1
2    A  politics       2
3    A  politics       2
4    C    lawyer       3
5    C     judge       3
6    C     judge       3
7    C    lawyer       4

我希望C区域的人能够查看他们是否既是律师又是法官，并将结果输出到第二个DataFrame，诸如此类喜欢

   person  jobtype
0       1  None
1       2  None
3       3  LAWYER_JUDGE
4       4  None

这对于 Pandas 来说可能吗？

Answer 1

这是寻找同时拥有律师和法官的人的一种方法

In [43]: zoomin = lambda x: None if len(np.setdiff1d(['judge', 'lawyer'], x['job type'])) else 'lawyer_judge'

In [44]: df.groupby('person').apply(zoomin)
Out[44]:
person
1            None
2            None
3    lawyer_judge
4            None
dtype: object