title: Package Python3.7 is not available
body: <p>So I have python 3.8 and pip for it, but I want to install stable python 3.7 and pip for it also. But when I try
  <code>sudo apt-get install python3.7</code>
  It says package is not available but is referred to another package.
  Help please
  Error:</p>
  <pre><code>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
  </code></pre>