Oh c'mon Zoidberg, that's a strawman argument. "with" is a Python keyword and the statement syntax is in the grammar. I would expect any working Python developer to know what it is, and even understand how to write a context manager.

...wait wat? It's in the Standard Library? No, I just checked and it's not. Too bad, if it was "blessed" by inclusion in the library I would totally withdraw my objection on that grounds.

You had me going for a second there. ;-)

You make my point for me though when you say that you'd have to read up on it when you first encountered it. That's exactly my point:

The trade off is between one application of attr to the code base to save N time/effort for the current developer one time, versus every bit of lost time/effort of future devs taken to understand the attr package.

It's cute, but it's an in-joke. Don't put in-jokes in code you want other people to use, otherwise they have to "get the joke" before they can work with it. That's what I'm on about.