所以我有python 3.8和pip，但我也想安装稳定的python 3.7和pip。但是当我尝试
sudo apt-get install python3.7
它说该软件包不可用，但被称为另一个软件包。
请帮忙
错误：
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package python3.7 is not available,but is referred to by another package.
This may mean that the package is missing,has been obsoleted,or
is only available from another source
E: Package 'python3.7' has no installation candidate