They are most of the time a fantastic indicator of the cognitive load a feature will add in prod. Because of course a feature doesn't exist in a vacuum, it's always in a more complex context. So what's easy to understand for a student will be alright for a pro in the complexity of real life engineering. And I found the opposite to hold quite often as well.
I haven't tried the walrus on them yet, but I'm pretty sure of the result.
That is fine if you want to optimize language for "fresh students". That is not representative how brain process stuff after getting even some experience.
m = re.match(...)
if m:
... do something ...
if m := re.match(...):
... do something ...
There are already so many complicated semantics about mutability, iteration, bytes/strings, scoping, et al. And yet somehow a tiny piece of syntax that finally lets us stop writing "while true/break" is the big pain point?