星火安装mendeley的19.8版本，在23的最新系统中。这个比较方便文献的pdf管理。但是失败了，提示如下：

包管理器以错误代码退出.日志如下

[apt-fast 23:08:03]

[apt-fast 23:08:03]Working... this may take a while.

[apt-fast 23:08:03]正在工作中，请稍等

[apt-fast 23:08:03]Reading package lists...

Building dependency tree...

Reading state information...

Some packages could not be installed. This may mean that you have

requested an impossible situation or if you are using the unstable

distribution that some required packages have not yet been created

or been moved out of Incoming.

The following information may help to resolve the situation:

The following packages have unmet dependencies:

mendeleydesktop : Depends: python but it is not installable

然后我尝试安装python，提示如下：

没有可用的软件包 python，但是它被其它的软件包引用了。
这可能意味着这个缺失的软件包可能已被废弃，
或者只能在其他发布源中找到
然而下列软件包会取代它：
python-is-python3 2to3

E: 软件包 python 没有可安装候选

请问该如何解决 ？