大家好，我在过去一周遇到了这个奇怪的错误，因为我无法安装新软件。我运行了这个命令：sudo apt install uniconf-tools
这之后出现了：
> Reading package lists... Done Building dependency tree Reading
> state information... Done uniconf-tools is already the newest version
> (4.6.1-7). 0 upgraded, 0 newly installed, 0 to remove and 16 not
> upgraded. 4 not fully installed or removed. After this operation, 0 B
> of additional disk space will be used. Do you want to continue? [Y/n]
> y Setting up update-notifier-common (3.168.5) ... Traceback (most
> recent call last): File
> "/usr/lib/update-notifier/package-data-downloader", …我的系统上目前有 python 3.6.3（ubunut 16.04）。但我发现 ubuntu 16.04 不支持 python 3.6，所以我想在我的系统上安装 python 3.5。
我从这里安装它。
谁能详细说说怎么做...