def check(info_date, current_amount, month_pay):
assert get_credit_info(info_date, **credit_config) == Credit(
get_date(credit_config["start_date"]), get_date(credit_config["end_date"]),
Decimal(credit_config["amount"]), Decimal(current_amount),
Decimal(credit_config["interest"]), None if month_pay is None else Decimal(month_pay),
_calculate(credit_config["start_date"], credit_config["end_date"],
credit_config["amount"], credit_config["interest"], credit_config["payments"]))
def test_iter_months_from_year_to_year():
assert list(_iter_months("15.11.2013", "15.02.2014")) == [
get_date("15.11.2013"),
get_date("15.12.2013"),
get_date("15.01.2014"),
get_date("15.02.2014")
]
def get_credit_info(info_date,
start_date,
end_date,
amount,
interest,
payments={}):
info_date = get_date(info_date)
start_date = get_date(start_date)
end_date = get_date(end_date)
amount = Decimal(amount)
interest = Decimal(interest)
payment_schedule = _calculate(start_date, end_date, amount, interest,
payments)
month_pay = None
if info_date <= end_date:
prev_date = start_date
current_amount = amount
for payment in payment_schedule:
if not (payment.date <= info_date or prev_date < info_date):
break
if payment.date <= info_date:
current_amount = payment.credit
month_pay = payment.month_pay
prev_date = payment.date
else:
current_amount = 0
return Credit(start_date, end_date, amount, current_amount, interest,
month_pay, payment_schedule)
def _calculate(start_date, end_date, credit, interest, payments={}):
start_date = get_date(start_date)
end_date = get_date(end_date)
credit = Decimal(credit)
payments = {get_date(date): Decimal(payment) for date, payment in payments.items()}
schedule = []
prev_date = start_date
cur_month_pay = month_pay = None
for date, month_interest in _iter_month_interest(start_date, end_date, interest):
if month_pay is None or cur_month_pay != month_pay:
month_pay = _get_month_pay(prev_date, end_date, credit, interest)
cur_month_pay = payments.pop(date, month_pay)
if cur_month_pay < month_pay:
raise InvalidPaymentError("Invalid payment for {}.", format_date(date))
interest_pay = _round_payment(credit * month_interest)
credit_pay = cur_month_pay - interest_pay
credit -= credit_pay
schedule.append(Payment(date, credit_pay, interest_pay, cur_month_pay, credit))
prev_date = date
if payments:
raise InvalidPaymentDateError("Invalid payment date: {}.", format_date(payments.popitem()[0]))
if credit:
payment = schedule[-1]
schedule[-1] = Payment(payment.date, payment.credit_pay + credit, interest_pay, payment.month_pay + credit, 0)
return schedule
def get_credit_info(info_date, start_date, end_date, amount, interest, payments={}):
info_date = get_date(info_date)
start_date = get_date(start_date)
end_date = get_date(end_date)
amount = Decimal(amount)
interest = Decimal(interest)
payment_schedule = _calculate(start_date, end_date, amount, interest, payments)
month_pay = None
if info_date <= end_date:
prev_date = start_date
current_amount = amount
for payment in payment_schedule:
if not (payment.date <= info_date or prev_date < info_date):
break
if payment.date <= info_date:
current_amount = payment.credit
month_pay = payment.month_pay
prev_date = payment.date
else:
current_amount = 0
return Credit(start_date, end_date, amount, current_amount, interest, month_pay, payment_schedule)
def test_iter_months_with_non_existing_days_in_months():
assert list(_iter_months("31.12.2012", "30.04.2013")) == [
get_date("31.12.2012"),
get_date("31.01.2013"),
get_date("28.02.2013"),
get_date("31.03.2013"),
get_date("30.04.2013")
]
def check(info_date, current_amount, month_pay):
assert get_credit_info(info_date, **credit_config) == Credit(
get_date(credit_config["start_date"]),
get_date(credit_config["end_date"]),
Decimal(credit_config["amount"]), Decimal(current_amount),
Decimal(credit_config["interest"]),
None if month_pay is None else Decimal(month_pay),
_calculate(credit_config["start_date"], credit_config["end_date"],
credit_config["amount"], credit_config["interest"],
credit_config["payments"]))
def _calculate(start_date, end_date, credit, interest, payments={}):
start_date = get_date(start_date)
end_date = get_date(end_date)
credit = Decimal(credit)
payments = {
get_date(date): Decimal(payment)
for date, payment in payments.items()
}
schedule = []
prev_date = start_date
cur_month_pay = month_pay = None
for date, month_interest in _iter_month_interest(start_date, end_date,
interest):
if month_pay is None or cur_month_pay != month_pay:
month_pay = _get_month_pay(prev_date, end_date, credit, interest)
cur_month_pay = payments.pop(date, month_pay)
if cur_month_pay < month_pay:
raise InvalidPaymentError("Invalid payment for {}.",
format_date(date))
interest_pay = _round_payment(credit * month_interest)
credit_pay = cur_month_pay - interest_pay
credit -= credit_pay
schedule.append(
Payment(date, credit_pay, interest_pay, cur_month_pay, credit))
prev_date = date
if payments:
raise InvalidPaymentDateError("Invalid payment date: {}.",
format_date(payments.popitem()[0]))
if credit:
payment = schedule[-1]
schedule[-1] = Payment(payment.date, payment.credit_pay + credit,
interest_pay, payment.month_pay + credit, 0)
return schedule
def _iter_months(start_date_string, end_date_string):
date = get_date(start_date_string)
end_date = get_date(end_date_string)
start_day = date.day
yield date
while date != end_date:
if date > end_date:
raise InvalidDateRangeError(start_date_string, end_date_string)
if date.month == 12:
year = date.year + 1
month = 1
else:
year = date.year
month = date.month + 1
date = _nearest_valid_date(year, month, start_day)
yield date
def _iter_months(start_date_string, end_date_string):
date = get_date(start_date_string)
end_date = get_date(end_date_string)
start_day = date.day
yield date
while date != end_date:
if date > end_date:
raise InvalidDateRangeError(start_date_string, end_date_string)
if date.month == 12:
year = date.year + 1
month = 1
else:
year = date.year
month = date.month + 1
date = _nearest_valid_date(year, month, start_day)
yield date
def _check_payment(payment, date, credit_pay, interest_pay, month_pay, overall_precision="0.01"):
def check(payment, right_payment, precision):
right_payment = Decimal(right_payment)
assert right_payment - precision <= payment <= right_payment + precision
exact_precision = Decimal("0.01")
overall_precision = Decimal(overall_precision)
assert payment.date == get_date(date)
check(payment.credit_pay, credit_pay, overall_precision)
check(payment.interest_pay, interest_pay, exact_precision)
check(payment.credit_pay + payment.interest_pay, month_pay, overall_precision)
check(payment.month_pay, month_pay, overall_precision)
def _check_payment(payment,
date,
credit_pay,
interest_pay,
month_pay,
overall_precision="0.01"):
def check(payment, right_payment, precision):
right_payment = Decimal(right_payment)
assert right_payment - precision <= payment <= right_payment + precision
exact_precision = Decimal("0.01")
overall_precision = Decimal(overall_precision)
assert payment.date == get_date(date)
check(payment.credit_pay, credit_pay, overall_precision)
check(payment.interest_pay, interest_pay, exact_precision)
check(payment.credit_pay + payment.interest_pay, month_pay,
overall_precision)
check(payment.month_pay, month_pay, overall_precision)
def test_iter_months_from_year_to_year():
assert list(_iter_months("15.11.2013", "15.02.2014")) == [
get_date("15.11.2013"), get_date("15.12.2013"),
get_date("15.01.2014"), get_date("15.02.2014") ]
def test_get_date():
date = Date(2013, 3, 13)
assert get_date(date) is date
def test_iter_months_simple():
assert list(_iter_months("15.03.2013", "15.05.2013")) == [
get_date("15.03.2013"), get_date("15.04.2013"), get_date("15.05.2013") ]
def test_get_date_invalid():
with pytest.raises(InvalidDateError):
get_date("31.02.2013")
def test_iter_months_simple():
assert list(_iter_months("15.03.2013", "15.05.2013")) == [
get_date("15.03.2013"),
get_date("15.04.2013"),
get_date("15.05.2013")
]
def test_get_date_invalid():
with pytest.raises(InvalidDateError):
get_date("31.02.2013")
def test_get_date_from_string():
assert get_date("13.03.2013") == Date(2013, 3, 13)
def test_iter_months_with_non_existing_days_in_months():
assert list(_iter_months("31.12.2012", "30.04.2013")) == [
get_date("31.12.2012"), get_date("31.01.2013"),
get_date("28.02.2013"), get_date("31.03.2013"),
get_date("30.04.2013") ]
def test_get_date():
date = Date(2013, 3, 13)
assert get_date(date) is date
def test_get_date_from_string():
assert get_date("13.03.2013") == Date(2013, 3, 13)
