title: Python 3.7 on Ubuntu 20.04
body: <p>I am preparing a docker image for Ubuntu 20.04 and due to TensorFlow 2.0 requirement, I need Python 3.7. TensorFlow runs on Python 3.5 to 3.7. Running <code>apt install python3</code> installs Python 3.8 by default and that breaks my TensorFlow installation.</p>
  <p>Is there any way I can get an apt package for Python 3.7 for Ubuntu 20.04? Since it is going to be inside docker image, I don't want to get into the business of downloading Python 3.7 source code and compiling. Putting those commands in Dockerfile will be overwhelming for me. Is there any simpler way of getting Python 3.7 for Ubuntu 20.04?</p>
  <p>Running</p>
  <pre><code>sudo apt-cache madison python3
  </code></pre>
  <p>returns</p>
  <pre><code>python3 | 3.8.2-0ubuntu2 | http://in.archive.ubuntu.com/ubuntu focal/main amd64 Packages
  </code></pre>