5.6 groupby

This lesson shows the usage of groupby in pandas

Important

This lesson is still under development.

The material in this lesson is mostly inspired from pandas documentation for groupby and realpython However, it has been modified for easy of practice and understanding.

import pandas as pd

print(pd.__version__)

1.5.3

df = pd.DataFrame( {'a':['A','A','B','B','B','C'], 'b':[1,2,5,5,4,6]})

df

	a	b
0	A	1
1	A	2
2	B	5
3	B	5
4	B	4
5	C	6

df.groupby('a')['b'].apply(list)

a
A       [1, 2]
B    [5, 5, 4]
C          [6]
Name: b, dtype: object

df.groupby('a')['b'].apply(list).reset_index(name='new')

	a	new
0	A	[1, 2]
1	B	[5, 5, 4]
2	C	[6]