Python 3.7 on Ubuntu 20.04

Do you need Ubuntu 20.04? Ubuntu 18.04 comes with Python 3.6, and 3.7 available.

If you do, the deadsnakes PPA has Python 3.5-3.7 for Ubuntu 20.04 (Focal). To add it and install:

sudo add-apt-repository ppa:deadsnakes/ppa
sudo apt-get install python3.7

P.s. I'm not a dev and have no experience with Tensorflow so take this with a grain of salt.

(Sidenote: add-apt-repository runs apt-get update automatically, but that's not documented in man add-apt-repository, only add-apt-repository --help. This was fixed in a later release.)

Tensorflow 2.2 now supports python 3.8 so problem is solved now.