32.Python：函数的嵌套

# 函数的嵌套
# 1.函数的嵌套调用：在调用一个函数的过程中又调用其他函数
def max2(x, y):
    if x > y:
        return x
    else:
        return y


def max4(a, b, c, d):
    res1 = max2(a, b)
    res2 = max2(res1, c)
    res3 = max2(res2, d)

    return res3


res = max4(1, 2, 3, 4)
print(res)

# 2.函数的嵌套定义：在定义一个函数的过程中又定义其他函数


# 圆形
def circle(radius, action=0):
    from math import pi

    # print(pi)

    # 求圆形的周长
    def perimeter(radius):
        return 2*pi*radius

    # 求圆形的面积
    def area(radius):
        return pi*(radius**2)

    if action == 0:
        return perimeter(radius)
    elif action == 1:
        return area(radius)


res = circle(33, 1)
print(res)