Nice!

This is the kind of obvious tool that once it exists, you can’t really grok the fact it did not earlier, and that it took until now to exist.

It's not novel obviously. I have been using pup[1] for years. And xidel[2] is probably older.

[1] https://github.com/ericchiang/pup

[2] https://github.com/benibela/xidel