Python -----issubclass和isinstance

issubclass用于判断一个类是否为另一个类的子类，isinstance用于判断一个对象是否某类的一个实例

 import math

 class Point:
     def __init__(self, xValue, yValue):
         self.X = xValue
         self.Y = yValue

 class Circle(Point):
     def __init__(self, xValue, yValue, rValue):
         Point.__init__(self, xValue, yValue)
         self.Radious = rValue  

     def area(self):
         return math.pi * self.Radious ** 2

 print("Point bases:", Point.__bases__)
 print("Circle bases:", Circle.__bases__)  

 print("Circle is the subclass of Point:", issubclass(Circle, Point))
 print("Point is the subclass of Circle:", issubclass(Point, Circle))

 point = Point(3, 4)
 circle = Circle(4, 5, 2)
 print("point is an instace of Point:", isinstance(point, Point))
 print("circle is an instace of Point:", isinstance(circle, Point))