To be clear, I still write a ton of stuff in shell. I try to think ahead to whether what I want to do can be accomplished in shell + standard unix utilities more easily than in Python. I use Python if it's not easily possible in shell + unix utilities, or the script is likely to be more than a few hundred lines.

Here's one I probably should've written in Python - https://gist.github.com/jaysoffian/f39fa2da8e7f340550f9