我一直在尝试安装一些 Python 库和包，但不断收到此错误。这是一个示例，但我在 matplotlib 和 panda 等方面面临同样的问题。
sudo apt-get install python-scipy
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package python-scipy 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 'python-scipy' has no installation candidate
我尝试启用 Universe 存储库，结果发现它已经启用。所以我还无法弄清楚这个问题。预先感谢您的帮助。