Since you have recently discovered Rich, you may want rich-argparse (https://github.com/hamdanal/rich-argparse).
It colorizes argparse CLIs with little effort from the user.
DeepDiff (https://github.com/seperman/deepdiff) has helped me with testing.
I needed to compare two nested data structures but ignore any differences in floats (timestamps).
DeepDiff let me do it:
pzp (https://github.com/andreax79/pzp) is like fzf in pure Python to use in your programs.
Keep in mind it is currently version 0.0.x.
I have found bugs, but I think it is just cool that it exists.