list(map(tuple, df.groupby('date', as_index=False)['money'].sum().values))
Редактировать :
df = pd.DataFrame({'date': ['2018-01-01', '2018-01-05', '2018-02-15', '2019-03-17', '2018-01-05'],
'money': [20, 30, 7, 150, 15]})
#df['date'] = pd.to_datetime(df['date'])
#df = df.sort_values(by='date')
temporary = df.groupby('date', as_index=False)['money'].sum()
temporary['money_cum'] = temporary['money'].cumsum()
Результат:
>>> list(map(tuple, temporary[['date', 'money_cum']].values))
[('2018-01-01', 20),
('2018-01-05', 65),
('2018-02-15', 72),
('2019-03-17', 222)]