def buy(self, date, in_quantity, from_quantity, from_units="USD", lot_number = None):
lot_number = self.check_and_make_buy_lot_number(lot_number)
self.transactions.append(
Transaction(
date,
Transaction.float2decimal(in_quantity, self.sigfigs),
Transaction.float2decimal(from_quantity, 2),
self.units,
from_units,
lot_number
)
)
def sell(self, date, out_quantity, to_quantity, to_units="USD", lot_number=None):
gains = self.realized_gains(out_quantity, to_quantity, to_units, lot_number, date)
#print(sell_cost)
self.transactions.append(
Transaction(
date,
-1*Transaction.float2decimal(out_quantity, self.sigfigs),
-1*Transaction.float2decimal(to_quantity, self.sigfigs),
self.units,
to_units,
lot_number
)
)
return gains
def filter_transactions_by_date(self, date):
if date is None:
return self.transactions
else:
d = Transaction.parse_date(date)
# This is a generator, so be sure to make a list if you need to iterate more than once.
transactions_filtered = (x for x in self.transactions if x.date <= d)
return transactions_filtered
def unrealized_capital_gains(self, price, date=None):
transactions_filtered = list(self.filter_transactions_by_date(date))
# The unrealized capital gains are the shares remaining (i.e. not sold) in each lot,
# times the price gain, summed over each lot
lot_numbers = {x.lot_number for x in transactions_filtered}
running_total = 0
for lot_number in lot_numbers:
# DRY this up; I copy/pasted this from a different function!
lot_volume = sum(x.buy_quantity for x in transactions_filtered
if x.lot_number == lot_number)
[lot_cost] = [
Transaction.float2decimal(x.sell_quantity / x.buy_quantity, 2)
for x in transactions_filtered
if x.lot_number == lot_number and x.buy_quantity > 0
]
lot_gains = lot_volume * (Transaction.float2decimal(price, 2) -
lot_cost)
running_total += lot_gains
return running_total
def sell_all(self, date, to_quantity):
sell_price = Transaction.float2decimal(to_quantity, 2)/self.volume(date)
# DRY this up too, probably
transactions_filtered = list(self.filter_transactions_by_date(date))
lot_numbers = {x.lot_number for x in transactions_filtered}
output = list()
for lot in lot_numbers:
lot_volume = sum(x.buy_quantity for x in transactions_filtered if x.lot_number==lot)
if lot_volume > 0:
output.append(self.sell(date, lot_volume, lot_volume*sell_price, lot_number=lot))
return output
def realized_gains(self,
out_quantity,
to_quantity,
to_units,
lot_number,
date=None):
if lot_number is None:
raise Exception("You must specify a lot number when selling!")
transactions_filtered = list(self.filter_transactions_by_date(date))
lot_volume = sum(x.buy_quantity for x in transactions_filtered
if x.lot_number == lot_number)
out_quantity = Transaction.float2decimal(out_quantity, self.sigfigs)
to_quantity = Transaction.float2decimal(to_quantity, 2)
if lot_volume < out_quantity:
raise Exception(
"Can't sell more shares ({}) than are in the lot ({})!".format(
out_quantity, lot_volume))
[lot_cost] = [
x.sell_quantity / x.buy_quantity for x in transactions_filtered
if x.lot_number == lot_number and x.buy_quantity > 0
]
sell_cost = to_quantity / out_quantity
return (float(sell_cost) - float(lot_cost)) * float(out_quantity)
def cost_basis(self, date=None):
# DRY this up (somehow, hm.)
transactions_filtered = list(self.filter_transactions_by_date(date))
lot_numbers = {x.lot_number for x in transactions_filtered}
running_total = 0
for lot_number in lot_numers:
lot_volume = sum(x.buy_quantity for x in transactions_filtered
if x.lot_number == lot_number)
[lot_cost] = [
Transaction.float2decimal(x.sell_quantity / x.buy_quantity, 2)
for x in transactions_filtered
if x.lot_number == lot_number and x.buy_quantity > 0
]
running_total += lot_cost
return running_total
def unrealized_capital_gains(self, price, date=None):
transactions_filtered = self.filter_transactions_by_date(date)
cost_basis = self.__cost_basis_avg_method(date)
price = Transaction.float2decimal(price,2)
return price*self.volume()-cost_basis