#!/usr/bin/env python3
# -*- coding: utf-8 -*-


class MyObject(object):

    def __init__(self):
        self.x = 9

    def power(self):
        return self.x * self.x


obj = MyObject()

print("hasattr(obj, 'x') =", hasattr(obj, "x"))  # 有属性'x'吗？
print("hasattr(obj, 'y') =", hasattr(obj, "y"))  # 有属性'y'吗？
setattr(obj, "y", 19)  # 设置一个属性'y'
print("hasattr(obj, 'y') =", hasattr(obj, "y"))  # 有属性'y'吗？
print("getattr(obj, 'y') =", getattr(obj, "y"))  # 获取属性'y'
print("obj.y =", obj.y)  # 获取属性'y'

print("getattr(obj, 'z') =", getattr(obj, "z", 404))  # 获取属性'z'，如果不存在，返回默认值404

f = getattr(obj, "power")  # 获取属性'power'
print(f)
print(f())