CODE EXAMPLE FOR PYTHON

create dictionary without removing duplicates from dataframe

{k: g.to_dict(orient='records') for k, g in df.groupby(level=0)}
# {'bob': [{'age': 20, 'name': 'bob'}, {'age': 30, 'name': 'bob'}],
#  'jim': [{'age': 25, 'name': 'jim'}]}