Pandas: Convert dataframe to dict of lists

Question

I have a dataframe like this:

col1, col2
A      0
A      1
B      2
C      3

I would like to get this:

{ A: [0,1], B: [2],          


        

Answer 1

You can use a dictionary comprehension on a groupby.

>>> {idx: group['col2'].tolist() 
     for idx, group in df.groupby('col1')}
{'A': [0, 1], 'B': [2], 'C': [3]}

Answer 2

Solution

df.groupby('col1')['col2'].apply(lambda x: x.tolist()).to_dict()

{'A': [0, 1], 'B': [2], 'C': [3]}