#例1
def func():
    print("我是递归")
    func()
func()

#例2
import os
def func(lujing,n):
 lst = os.listdir(lujing)
 for i in lst:
     path = os.path.join(lujing,i)
     #判断是文件还是文件夹
     if os.path.isdir(path):
         print("..." * n,i)
         func(path,n + 1 )
     else:
         print(i)
func("e:/a",0)