Pandas groupby two columns then get dict for values

Question

I have a pandas dataframe:

banned_titles = 
TitleId  RelatedTitleId
0    89989           32598
1    89989         3085083
2    95281         3085083
<         


        

Answer 1

Try list one line (no lambda):

dict(df.groupby('TitleId')['RelatedTitleId'].apply(list))
 # {89989: [32598, 3085083], 95281: [3085083]}

Answer 2

try this:

In [8]: x.groupby('TitleId')['RelatedTitleId'].apply(lambda x: x.tolist()).to_dict()
Out[8]: {89989: [32598, 3085083], 95281: [3085083]}

or as series of lists:

In [10]: x.groupby('TitleId')['RelatedTitleId'].apply(lambda x: x.tolist())
Out[10]:
TitleId
89989    [32598, 3085083]
95281           [3085083]
Name: RelatedTitleId, dtype: object

data:

In [9]: x
Out[9]:
   TitleId  RelatedTitleId
0    89989           32598
1    89989         3085083
2    95281         3085083