Grouping rows and adding average of group values to Dataframe

Question

I have a dataframe where I need to create a grouping of ages and then have the averages amount of Tip amount for each group.

My Data looks the following

Tip amount	Age
3	30
30	35
4	60
1	12
7	25
3	45
15	31
5	8

I have tried to use pd.cut() with bins to create the grouping, but I can't seem to get the Tip amount average (maybe using mean() ) to be in the DataFrame as well.

import pandas as pd

bins= [0,15,30,45,60,85]
labels = ['0-14','15-29','30-44','45-59','60+']

df['Tip amount']=df['Tip amount'].astype(int)
#df = df.groupby('Age')[['Tip amount']].mean()
df = df.groupby(pd.cut(df['Age'], bins=bins, labels=labels, right=False)).size()

This gives the following output:

Age
0-14	2
15-29	1
30-44	3
45-59	1
60+	1

But I would like to have the average Tip amount for the groups as well.

Age		Tip amount
0-14	2	avg
15-29	1	avg
30-44	3	avg
45-59	1	avg
60+	1	avg

Answer 1

Try:

df.groupby(pd.cut(df['Age'], bins=bins, labels=labels, right=False)).agg({'Age': ['size'], 'Tip amount': ['mean']})