使用for循环逐个调用area并且输出面积

国庆考核.py

@@ -1,3 +1,21 @@
 class Shape:
     def area(self):
         return 0
+
+class Circle(Shape):
+    def __init__(self, r):
+        self.r = r
+    def area(self):
+        return 3.14 * self.r * self.r
+
+class Square(Shape):
+    def __init__(self, side):
+        self.side = side
+    def area(self):
+        return self.side * self.side
+
+r = int(input("请输入圆的半径: "))
+side = int(input("请输入正方形的边长: "))
+shapes = [Circle(r), Square(side)]
+for i in shapes:
+    print(i.__class__.__name__ + "的面积为: " + str(i.area()))