def test_tdd():
accounts = Ledger('equity')
accounts.make_stock_accounts(['cash', 'claims', 'inventory'])
accounts.make_flow_accounts(['expenditure', 'revenue', 'cost of goods sold', 'depreciation'])
accounts.book(
debit=[('cash', 50), ('claims', 50)],
credit=[('equity', 100)],
text="Start with owners' equity, partially paid in")
assert accounts._check_debit_eq_credit()
assert accounts.get_total_assets() == 100
assert accounts['cash'].get_balance() == (AccountSide.DEBIT, 50)
assert accounts['claims'].get_balance() == (AccountSide.DEBIT, 50)
assert accounts['equity'].get_balance() == (AccountSide.CREDIT, 100)
print('Initial balance')
accounts.print_balance_sheet()
print('Some purchases and operating expenses')
accounts.book(debit=[('expenditure', 20)], credit=[('cash', 20)],text="General expenses")
assert accounts.get_total_assets() == 80, accounts.get_total_assets()
accounts.book(debit=[('inventory',20)],credit=[('cash',20)],text="Purchase of equipment")
accounts.book(debit=[('depreciation',2)],credit=[('inventory',2)],text="Depreciation")
accounts.print_profit_and_loss()
print('Balance sheet after first period')
accounts.book_end_of_period()
accounts.print_balance_sheet()
assert accounts['equity'].get_balance() == (AccountSide.CREDIT, 78)
assert accounts['cash'].get_balance() == (AccountSide.DEBIT, 10),accounts['cash'].get_balance()
print('Profitable sale')
accounts.book(debit=[('cash',40)],credit=[('revenue',40)],text="Sale of goods")
accounts.book(debit=[('cost of goods sold',10)],credit=[('inventory',10)],text="Sale of goods")
accounts.print_profit_and_loss()
assert accounts['inventory'].get_balance() == (AccountSide.DEBIT, 8)
print('Balance sheet after second period')
accounts.book_end_of_period()
accounts.print_balance_sheet()
assert accounts['equity'].get_balance() == (AccountSide.CREDIT, 108)
""" ---------------------------------------------------------------------------
Initialize balance sheets (all symmetric balance sheets with 0 equity, for simplicity)
"""
fed.book(debit=[('Securities Holdings',1000)],credit=[('Securities belonging to Depository A',500),('Securities belonging to Depository B',500)])
fed.book(debit=[('Assets',2000)],credit=[('Reserves Depository A',1000),('Reserves Depository B',1000)])
depository_A.book(debit=[('Securities Holdings',1000)],credit=[('Securities belonging to Broker M',1000)])
depository_A.book(debit=[('Reserves',1000)],credit=[('Deposits by Broker M',1000)])
depository_B.book(debit=[('Securities Holdings',1000)],credit=[('Securities belonging to Financial Institution J',1000)])
depository_B.book(debit=[('Reserves',1000)],credit=[('Deposits by Financial Institution J',1000)])
broker_M.book(debit=[('Securities Holdings',1000)],credit=[('Securities belonging to Customers',1000)])
broker_M.book(debit=[('Reserves with Depository A',1000)],credit=[('Customer Deposits',1000)])
fi_J.book(debit=[('Securities Holdings',1000)],credit=[('Securities belonging to Customers',1000)])
fi_J.book(debit=[('Reserves with Depository B',1000)],credit=[('Customer Deposits',1000)])
print('Initial balance sheets:')
fed.print_balance_sheet()
depository_A.print_balance_sheet()
depository_B.print_balance_sheet()
broker_M.print_balance_sheet()
fi_J.print_balance_sheet()
""" ---------------------------------------------------------------------------
Transfer of a security from a customer of Broker M to a customer of Financial Institution J
The booking statements on the customers' balance sheet are left out for brevity, they would be completely analogous
"""
broker_M.book(debit=[('Securities belonging to Customers',500)],credit=[('Securities Holdings',500)])
depository_A.book(debit=[('Securities belonging to Broker M',500)],credit=[('Securities Holdings',500)])
fed.book(debit=[('Securities belonging to Depository A',500)],credit=[('Securities belonging to Depository B',500)])
depository_B.book(debit=[('Securities Holdings',500)],credit=[('Securities belonging to Financial Institution J',500)])
fi_J.book(debit=[('Securities Holdings',500)],credit=[('Securities belonging to Customers',500)])
private_agent.book(debit=[('Currency', 500)], credit=[('Equity', 500)])
bank.book(debit=[('Currency', 50)], credit=[('Equity', 50)])
central_bank.book(debit=[('Assets', 550)], credit=[('Currency', 550)])
private_agent.book(debit=[('Deposits', 500)], credit=[('Currency', 500)])
bank.book(debit=[('Currency', 500)], credit=[('Deposits', 500)])
bank.book(debit=[('Reserves', 550)], credit=[('Currency', 550)])
central_bank.book(debit=[('Currency', 550)], credit=[('Reserves', 550)])
""" ---------------------------------------------------------------------------
Bank buys a government bond
"""
government.book(debit=[('Reserves', 400)], credit=[('Bonds', 400)])
bank.book(debit=[('Bonds', 400)], credit=[('Reserves', 400)])
central_bank.book(debit=[('Reserves', 400)],
credit=[('Government Reserves', 400)])
""" ---------------------------------------------------------------------------
Private agent buys the bond from the bank
"""
private_agent.book(debit=[('Bonds', 100)], credit=[('Deposits', 100)])
bank.book(debit=[('Deposits', 100)], credit=[('Bonds', 100)])
""" ---------------------------------------------------------------------------
Take out a loan
"""
private_agent.book(debit=[('Deposits', 550)], credit=[('Loans', 550)])
bank.book(debit=[('Loans', 550)], credit=[('Deposits', 550)])
private_agent.print_balance_sheet()
bank.print_balance_sheet()
central_bank.print_balance_sheet()
government.print_balance_sheet()
household.book(debit=[('loan liabilities',100)],credit=[('money holdings',100)],text='Principal repayment')
""" ---------------------------------------------------------------------------
Dividend payment
"""
bank.book(debit=[('equity',5)],credit=[('deposits',5)],text='Dividend payout')
bank_owner.book(debit=[('money holdings',5)],credit=[('income',5)],text='Dividend income')
bank.book_end_of_period()
household.book_end_of_period()
bank_owner.book_end_of_period()
print('Bank initial balance sheet')
bank.print_balance_sheet()
print('Household initial balance sheet')
household.print_balance_sheet()
print('Bank owner initial balance sheet')
bank_owner.print_balance_sheet()
print('Bank PnL after interest payment')
bank.print_profit_and_loss()
print('Household PnL after interest payment')
household.print_profit_and_loss()
bank.book_end_of_period()
household.book_end_of_period()
print('Bank balance sheet after dividend payment')
bank.print_balance_sheet()
print('Household balance sheet after dividend payment')
def test_banking():
bank = Ledger(residual_account_name="equity")
household = Ledger(residual_account_name="equity")
bank.make_stock_accounts(['reserves','claims','security holdings','deposits','wholesale refinancing'])
household.make_stock_accounts(['money holdings','loan liabilities'])
bank.make_flow_accounts(['interest income','interest expense'])
household.make_flow_accounts(['income','expenses'])
""" ---------------------------------------------------------------------------
Initialize balance sheets (outside money endowments)
"""
household.book(debit=[('money holdings',100)],credit=[('equity',100)],text='Initial endowment')
bank.book(debit=[('reserves',100)],credit=([('deposits',100)]),text='Initial endowment')
print('Bank initial balance sheet')
bank.print_balance_sheet()
print('Household initial balance sheet')
household.print_balance_sheet()
""" ---------------------------------------------------------------------------
Granting of a loan
"""
bank.book(debit=[('claims',10)],credit=[('deposits',10)],text='Loan')
household.book(debit=[('money holdings',10)],credit=[('loan liabilities',10)],text='Loan')
print('Bank balance sheet after granting a loan')
bank.print_balance_sheet()
print('Household balance sheet after granting a loan')
household.print_balance_sheet()
""" ---------------------------------------------------------------------------
Interest payment
"""
bank.book(debit=[('deposits',1)],credit=[('interest income',1)],text='Interest payment')
household.book(debit=[('expenses',1)],credit=[('money holdings',1)],text='Interest payment')
print('Bank PnL after interest payment')
bank.print_profit_and_loss()
print('Household PnL after interest payment')
household.print_profit_and_loss()
bank.book_end_of_period()
household.book_end_of_period()
print('Bank balance sheet after interest payment')
bank.print_balance_sheet()
print('Household balance sheet after interest payment')
household.print_balance_sheet()
""" ---------------------------------------------------------------------------
Principal repayment
"""
bank.book(debit=[('deposits',10)],credit=[('claims',10)],text='Principal repayment')
household.book(debit=[('loan liabilities',10)],credit=[('money holdings',10)],text='Principal repayment')
print('Bank balance sheet after principal repayment')
bank.print_balance_sheet()
print('Household balance sheet after principal repayment')
household.print_balance_sheet()
""" ---------------------------------------------------------------------------
Dividend payment
"""
bank.book(debit=[('equity',1)],credit=[('deposits',1)],text='Dividend payment')
household.book(debit=[('money holdings',1)],credit=[('income',1)],text='Dividend payment')
print('Bank PnL after interest payment')
bank.print_profit_and_loss()
print('Household PnL after interest payment')
household.print_profit_and_loss()
bank.book_end_of_period()
household.book_end_of_period()
print('Bank balance sheet after dividend payment')
bank.print_balance_sheet()
print('Household balance sheet after dividend payment')
household.print_balance_sheet()