如何在继承自抽象基类的类中定义方法

Question

I have two abstract Classes with two methods: getArea(width, height) and getPerimeter(width, height) . Those methods are abstract too, so they can be (or not) implemented in a derived class (In my case they must be implemented). In C# I could write IRectangle.getArea(){} or IParallelogram.getPerimeter(){} and simply make implementation. How can I do this in Python? I think that I have to use something like super(IRectangle, self).getArea() but I am not sure how.

from abc import ABC, abstractmethod

class IRectangle(ABC):
  @abstractmethod
  def getArea(width, height):
    pass
  @abstractmethod
  def getPerimeter(width, height):
    pass

class IParallelogram(ABC):
  @abstractmethod
  def getArea(parHeight, parBase):
      pass
  @abstractmethod
  def getPerimeter(parHeight, parBase):
    pass

class Calculate (IParallelogram, IRectangle):

Answer 1

You would just make a class that inherits from the abstract class and overrides the abstract methods like you would write a regular method.

class A(ABC):
    @abstractmethod
    def f(self):
        pass

class B(A):
    def f(self):
        print ('hello')

If you want to override it but make it do nothing:

class B(A):
    def f(self):
        pass

Answer 2

Your class hierarchy is upside down. First, you would define a more generic class like Shape as the (abstract) root of the hierarchy.

class Shape(ABC):
    @abstractmethod
    def getArea(self):
        pass

    @abstractmethod
    def getPerimeter(self):
        pass

Then, the concrete classes IRectangle and IParallelogram would implement getArea and getPerimeter appropriately.

class IRectangle(Shape):
    def getArea(self):
        ...

    def getPerimeter(self):
        ...

class IParallelogram:
    def getArea(self):
        ...

    def getPerimeter(self):
        ...