# house
users = meta.Session.query(model.User)
- debts_dict = {}
+ debts_dict = dict((u, Currency(0)) for u in users)
# First, credit everyone for expenditures they've made
- for user in users:
- debts_dict[user] = Currency(-sum(map((lambda x: x.amount), user.expenditures)))
+ total_expenditures = meta.Session.query(model.Expenditure).\
+ add_column(sqlalchemy.func.sum(model.Expenditure.amount).label('total_spend')).\
+ group_by(model.Expenditure.spender_id)
+ for expenditure, total_spend in total_expenditures:
+ debts_dict[expenditure.spender] -= total_spend
# Next, debit everyone for expenditures that they have an
# investment in (i.e. splits)