嵌套函数
嵌套函数（Nested function）是在另一个函数（即：封闭函数）中定义的函数
引用自：https://blog.csdn.net/liang19890820/article/details/73864242
def hi(name = "yasoob"):
print("now you are inside the hi() function")
def greet():
return "you are in greet() function"
def welcome():
return "you are in welcome() function"
print(greet())
print(welcome())
print("back in hi() function")
hi()
执行结果：
now you are inside the hi() function
you are in greet() function
you are in welcome() function
back in hi() function
小结
通过该示例，学习Python中嵌套函数的用法，装饰器一部分特性体现在也是一个嵌套函数。
