from datetime import date from typing import List

class Employee: """An employee of a company.

This is an abstract class. Only child classes should be instantiated.

=== Public attributes === id_: This employee's ID number. name: This employee's name. """ id_: int name: str

def __init__(self, id_: int, name: str) -> None: """Initialize this employee.

Note: This initializer is meant for internal use only; Employee is an abstract class and should not be instantiated directly. """ self.id_ = id_ self.name = name

def get_monthly_payment(self) -> float: """Return the amount that this Employee should be paid in one month.

Round the amount to the nearest cent. """ raise NotImplementedError

def pay(self, pay_date: date) -> None: """Pay this Employee on the given date and record the payment.

(Assume this is called once per month.) """ payment = self.get_monthly_payment() print(f'An employee was paid {payment} on {pay_date}.')

def total_pay(self) -> float: """Return the total amount of pay this Employee has received.

>>> e = SalariedEmployee(14, 'Gilbert the cat', 1200.0) >>> e.pay(date(2018, 6, 28)) An employee was paid 100.0 on 2018-06-28. >>> e.pay(date(2018, 7, 28)) An employee was paid 100.0 on 2018-07-28. >>> e.pay(date(2018, 8, 28)) An employee was paid 100.0 on 2018-08-28. >>> e.total_pay() 300.0 """ # TODO: implement this method! pass

class SalariedEmployee(Employee): """An employee whose pay is computed based on an annual salary.

=== Public attributes === salary: This employee's annual salary

=== Representation invariants === - salary >= 0 """ id_: int name: str salary: float

def __init__(self, id_: int, name: str, salary: float) -> None: """Initialize this salaried Employee.

>>> e = SalariedEmployee(14, 'Fred Flintstone', 5200.0) >>> e.salary 5200.0 """ # Note that to call the superclass' initializer, we need to use the # full name '__init__'. This is the only time we write '__init__' # explicitly. Employee.__init__(self, id_, name) self.salary = salary

def get_monthly_payment(self) -> float: """Return the amount that this Employee should be paid in one month.

Round the amount to the nearest cent.

>>> e = SalariedEmployee(99, 'Mr Slate', 120000.0) >>> e.get_monthly_payment() 10000.0 """ return round(self.salary / 12, 2)

class HourlyEmployee(Employee): """An employee whose pay is computed based on an hourly rate.

=== Public attributes === hourly_wage: This employee's hourly rate of pay. hours_per_month: The number of hours this employee works each month.

=== Representation invariants === - hourly_wage >= 0 - hours_per_month >= 0 """ id_: int name: str hourly_wage: float hours_per_month: float

def __init__(self, id_: int, name: str, hourly_wage: float, hours_per_month: float) -> None: """Initialize this HourlyEmployee.

>>> barney = HourlyEmployee(23, 'Barney Rubble', 1.25, 50.0) >>> barney.hourly_wage 1.25 >>> barney.hours_per_month 50.0 """ Employee.__init__(self, id_, name) self.hourly_wage = hourly_wage self.hours_per_month = hours_per_month

def get_monthly_payment(self) -> float: """Return the amount that this Employee should be paid in one month.

Round the amount to the nearest cent.

>>> e = HourlyEmployee(23, 'Barney Rubble', 1.25, 50.0) >>> e.get_monthly_payment() 62.5 """ return round(self.hours_per_month * self.hourly_wage, 2)

class Company: """A company with employees.

We use this class mainly as a client for the various Employee classes we defined in employee.

=== Attributes === employees: the employees in the company. """ employees: List[Employee]

def __init__(self, employees: List[Employee]) -> None: self.employees = employees

def pay_all(self, pay_date: date) -> None: """Pay all employees at this company.""" for employee in self.employees: employee.pay(pay_date)

def total_payroll(self) -> float: """Return the total of all payments ever made to all employees.

>>> my_corp = Company([\ SalariedEmployee(24, 'Gilbert the cat', 1200.0), \ HourlyEmployee(25, 'Chairman Meow', 500.25, 1.0)]) >>> my_corp.pay_all(date(2018, 6, 28)) An employee was paid 100.0 on 2018-06-28. An employee was paid 500.25 on 2018-06-28. >>> my_corp.total_payroll() 600.25 """ # TODO: implement this method! pass