python问题求解

写一个函数，将一个整数的各位数字按倒序排列，并编写测试程序在测试函数中输入整数和输出新的整数

#!/usr/bin/python
# -*- coding: UTF-8 -*-
"""
@author: Roc-xb
"""

def fun(num):
    print("输入的整数:", num)
    arr = []
    for n in str(num):
        arr.append(n)
    arr.sort()
    arr.reverse()
    result = int("".join(arr))
    print("输出的整数:", result)


if __name__ == '__main__':
    num = 123671673
    fun(num)

def my_fun(num):
    l = list(str(num))
    l = sorted(l, reverse=True)
    return int(''.join(l))


print(my_fun(12356))

# 65321