函数的嵌套

函数嵌套的定义

函数内部定义的函数,无法在函数外部使用内部定义的函数

def f1():
    def f2():
        print('from f2')
    f2()
f2()    ## NameError: name 'f2' is not defined

def f1():
    def f2():
        print('from f2')
    f2()
f1()  #from f2

定义一个circle函数,通过传参的形式得到园的面积或者周长

import cmath
def circle(r,action):
    if action=='area':
        return cmath.pi*r**2
    elif action=='length':
        return 2*cmath.pi*r
area=circle(3,'area')
print(area)
length=circle(3,'length')
print(length)

28.274333882308138
18.84955592153876

import cmath
def circle(r, action):
    def area():
        return cmath.pi * r ** 2
    def length():
        return 2*cmath.pi*r
    if action=='area':
        return area()
    else:
        return length()
area=circle(3,'area')
print(area)
length=circle(3,'length')
print(length)

28.274333882308138
18.84955592153876

#比较两个值
def self_max(x, y):
    if x > y:
        return x
    return y


res = self_max(10, 20)
print(res)

20

#比较四个值
def self_4_max(x, y, z, c):
    res1 = max(x, y)
    res2 = max(z, c)
    res= max(res1, res2)

    return res


res = self_4_max(10, 20, 1, 100)
print(res)

100

来源：https://www.cnblogs.com/aden668/p/11329310.html