qtile is a tiling window manager written in Python that I've been happily using for a few months now. On Ubuntu, Mint and similar Linux distributions it's unfortunately not available in the official repositories, so the easiest way to get it is either to replace Ubuntu with an Arch based distribution, or build it from source. Here I'll go through how to build it from source on Linux Mint 20.1 (has worked well for me on Ubuntu 20.04 as well).
Always be aware that installing programs outside of the official repositories might make your system less stable. I haven't personally had issues, but please be aware if you follow my instructions it's on your own risk. (And in case you are here many moons after 28 March 2021, you might just prefer following the official documentation instead.)
Besides taking a backup, you need to:
sudo apt install python3 python3-pip git
sudo apt install libxcb-render0-dev libffi-dev
pip3 install xcffib
sudo apt install libcairo2
pip3 install --no-cache-dir cairocffi
sudo apt-get install libpangocairo-1.0-0
pip3 install dbus-next
git clone git://github.com/qtile/qtile.git
pip3 install .
sudo vim /usr/share/xsessions/qtile.desktop
That's it! Logout, choose you want to log into qtile and start configuring your config located in: ~/.config/qtile/config.py
(If you need a reference, you can find my config over at sourcehut.)