将8进制数字(文件权限）转换为rwxrwxrwx格式字符显示

def get_rights(n):
    R = "rwxrwxrwx"        
    s = ''
    print(bin(n))
    for i in range(8, -1, -1):    #8-0
        if ((n>>i) & 1) == 1:
            s = s + R[8-i]
        else:
            s = s + '-'
        print(i+1, bin(n>>i), (n>>i)&1)
    return s

if __name__ == '__main__':
    print(get_rights(0o777))