KnowHow

class Employee(object):
    def __init__(self, _emp_id: int = None, _name: str = None, _salary: int = None) -> None:
        self.__emp_id = _emp_id
        self.__name = _name
        self.__salary = _salary

    # def get_salary(self) -> int:
    #     return self.__salary
    #
    # def set_salary(self, _salary: int) -> None:
    #     self.__salary = _salary

    @property
    def salary(self) -> int:
        return self.__salary

    @salary.setter
    def salary(self, _salary: int) -> None:
        if not isinstance(_salary, int):
            raise TypeError("Name must be a integer")
        self.__salary = _salary

    @staticmethod
    def work() -> None:
        return None


if __name__ == '__main__':
    employee = Employee(1, 'Jun', 100)
    print(employee.salary)
    employee.salary = 200
    print(employee.salary)
    # employee.salary = '100'

from abc import ABCMeta, abstractmethod


class IShape(metaclass=ABCMeta):
    @abstractmethod
    def calc_area(self) -> int:
        pass


class Rectangle(IShape):
    def __init__(self, _width: int, _height: int):
        self.__width = _width
        self.__height = _height

    def calc_area(self) -> int:
        return self.__width * self.__height


class Square(IShape):
    def __init__(self, _length: int):
        self.__length = _length

    def calc_area(self) -> int:
        return self.__length * self.__length


class Client(object):
    def __init__(self, _shape: IShape):
        self.shape = _shape


if __name__ == '__main__':
    rec = Rectangle(10, 20)
    squ = Square(10)

    client = Client(rec)
    print(client.shape.calc_area())

    client = Client(squ)
    print(client.shape.calc_area())