如何从 Python 中的 function 返回我的变量？

Question

How do I return my getArea? It is currently giving my None (default) as a result and I cannot fathom what piece is missing without the extra eyes.

Here I am focused on my Carpet Class which creates objects using the Rectangle class. Am I putting in the wrong print statement to test the getArea method of the Carpet class, or is the getArea method completely wrong? (Everything for Rug class worked as expected). Thank you in advance!

class Rectangle:
    # initialize
    def __init__(self, length, width):
        self.length = length
        self.width = width

    # length pair
    def getLength(self):
        return self.length

    def setLength(self, length):
        self.length = length

    #width pair
    def getWidth(self):
        return self.width
        
    def setWidth(self, width):
        self.width = width

class Rug(Rectangle):

    def __init__(self, length = 5, width = 7, price = 34.99):
        super().__init__(length, width)
        self.price = '$' + str(price)

    def getPrice(self):
        return self.price

class Carpet(Rectangle):

    def __init__(self, length, width, price_per_square_foot = 1.99):
        super().__init__(length, width)
        self.price_per_square_foot = price_per_square_foot

    def getArea(self):
        self.area = self.length * self.width

    def getPrice(self):
        return self.area * self.price_per_square_foot        

carp_1 = Carpet(3, 4)
print(carp_1.length)
print(carp_1.width)
print(carp_1.price_per_square_foot)
print(carp_1.getArea())
print(carp_1.getPrice()) 

'''rug_1 = Rug()     
print(rug_1.length)
print(rug_1.width)
print(rug_1.price)'''

Answer 1

You have to return self.length * self.width afterwords

Answer 2

You need to add a return statement to the getArea method. It should look like this:

def getArea(self):
    self.area = self.length * self.width
    return self.area