Source: https://forums.linuxmint.com/viewtopic.php?t=322849

sudo apt install powerline

Edit ~/.bashrc to insert the following (code snippet) section and save the file.

Note: You can place this section at the bottom of ~/.bashrc
TIP: For root ( when you run $ sudo -i ) you need to place this code in /root/.profile instead.

powerline-daemon -q
POWERLINE_BASH_CONTINUATION=1
POWERLINE_BASH_SELECT=1
source /usr/share/powerline/bindings/bash/powerline.sh

Or use:

https://github.com/chris-marsh/pureline