This is my customized fish_prompt.fish from ~/.config/fish/functions/fish_prompt.fish
Please feel free to copy and use this custom fish prompt in your terminal.
I used "Simple Pythonista" as a base template and customized it to my liking. You can find "Simple Pythonista" by typing the following command into terminal after fish is installed:
$ fish_config
A new browser window/tab should open and then select Prompt. Thre you can also view many others that are aviailble.
Here's a screenshot of my customized propmpt:
