python的如何通过实例方法名字的字符串调用方法?

实际代码

# lib1.py
class Circle(object):
    def __init__(self, r):
        self.r = r
    def area(self):
        return self.r **2* 3.14

#lib2.py
class Triangle(object):
    def __init__(self, a,b,c):
        self.a = a
        self.b = b
        self.c = c
    def getArea(self):
        a,b,c = self.a, self.b, self.c
        p = (a+b+c)/2
        area = (p * (p-a)* (p - b)* (p-c))** 0.5
        return area


#lib3.py
class Rectangle(object):
    def __init__ (self,w,h):
        self.w = w
        self.h = h
    def get_area(self): 
        return self.w * self.h

# from lib1 import circle
# from lib2 import Triangle
# from lib3 import Rectangle
def getArea(shape):
    for name in( 'area', 'getArea', 'get_area' ):
        f = getattr(shape,name,None)
        if f:
            return f()
        # continue

shape1 = Circle(2)
shape2 = Triangle(3,4,5)
shape3 = Rectangle(6,4)
shapes = [shape1, shape2, shape3]
print(list(map(getArea, shapes)))
# for i in shapes:
#     print(getArea(i))
输出:[12.56, 6.0, 24]

方法二 from operator import methodcaller