#!/usr/bin/python3
 
from math import pi
 
 
class Circle(object):
 def __init__(self, radius):
  self.radius = radius
 
 def getArea(self):
  return round(pow(self.radius, 2) * pi, 2)
 
 
class Rectangle(object):
 def __init__(self, width, height):
  self.width = width
  self.height = height
 
 def get_area(self):
  return self.width * self.height
 
 
# 定义统一接口
def func_area(obj):
 # 获取接口的字符串
 for get_func in ['get_area', 'getArea']:
  # 通过反射进行取方法
  func = getattr(obj, get_func, None)
  if func:
   return func()
  
 
if __name__ == '__main__':
 c1 = Circle(5.0)
 r1 = Rectangle(4.0, 5.0)
  
 # 通过map高阶函数，返回一个可迭代对象
 erea = map(func_area, [c1, r1])
 print(list(erea))　

#!/usr/bin/python3
 
from math import pi
from operator import methodcaller
 
 
class Circle(object):
 def __init__(self, radius):
  self.radius = radius
 
 def getArea(self):
  return round(pow(self.radius, 2) * pi, 2)
 
 
class Rectangle(object):
 def __init__(self, width, height):
  self.width = width
  self.height = height
   
 def get_area(self):
  return self.width * self.height
 
if __name__ == '__main__':
 c1 = Circle(5.0)
 r1 = Rectangle(4.0, 5.0)
  
 # 第一个参数是函数字符串名字，后面是函数要求传入的参数，执行括号中传入对象
 erea_c1 = methodcaller('getArea')(c1)
 erea_r1 = methodcaller('get_area')(r1)
 print(erea_c1, erea_r1)