Examples
import numpy as np
import pandas as pd
df = pd.DataFrame({'Animal': ['Tiger', 'Tiger',
'Dog', 'Dog'],
'Max Speed': [270., 260., 36., 32.]})
df
df.groupby(['Animal']).mean()
Hierarchical Indexes
We can groupby different levels of a hierarchical index using the level parameter:
arrays = [['Tiger', 'Tiger', 'Dog', 'Dog'],
['Captive', 'Wild', 'Captive', 'Wild']]
index = pd.MultiIndex.from_arrays(arrays, names=('Animal', 'Type'))
df = pd.DataFrame({'Max Speed': [280., 250., 30., 20.]},
index=index)
df
df.groupby(level=0).mean()
df.groupby(level=1).mean()