python-leofile make files to objects

leo do not like to use "os.path.join"
so this tiny class borned

在遍历文件的时候被path.join绕晕了
所以写了这个小工具

usage:
    path = '/etc'
    etc = Leofile(path)
    nginx_config = etc.nginx['nginx.conf'].open('r')
    nginx_config.read()