pandas: create a dictionary containing groups following a groupby operation

dictionary from groups.py

# pandas groupby, create a ditionary with groups using a comprehension
import pandas as pd
import numpy as np
df = pd.DataFrame({'key1': ['a','a','b','b','a'],
                   'key2': ['one', 'two', 'one', 'two', 'three'],
                   'data1': np.random.randn(5),
                   'data2': np.random.random(5)})
# by default the groupby selects all remaining columns
groups = df.groupby('key1')
res = {key1: group for key1, group in groups}
print(res['a'])
print(res['b'])