如何选择要在熊猫分组显示的列值

Question

I am using pandas 0.16.0, I have data:

id A  B
1  10 100
2  10 101
3  20 102

when I call

df.groupby(['A']).groups

I have

{10: [1 2], 20: [3]}

and I want to have this (values from column B)

{10: [100, 101], 20: [102]}

please help

Answer 1

One way is to groupby and apply function to take list, and then convert to dict.

In [92]: df.groupby(['A']).apply(lambda x: x['B'].tolist()).to_dict()
Out[92]: {10: [100, 101], 20: [102]}