This looks like a useful hack, but the implementation (as shown in Shawn's draft PEP) feels problematic -- you want the notation `SomeClass.some_class_method[various_parameters](arguments)` to invoke `SomeClass.class_method(arguments)` and convey `various_parameters` out of band, without changing the signature of `class_method`. The solution of using contextvars is clever, but I worry that it could be expensive -- that API wasn't designed for such a fine-grained usage. I also feel that it's a bit weird to use a much more general mechanism. Though maybe I'm being distracted by something you used just to get a feel for how the prototype would work? What other ways would there be to pass this information around? Maybe we should introspect the signature of `class_method` looking for a specific dunder-named keyword-only parameter? Or maybe we could wrap the `cls` argument in something that's a proxy except for an extra attribute? It looks like several others have attempted implementations -- what did they use? -- --Guido van Rossum (python.org/~guido) *Pronouns: he/him **(why is my pronoun here?)* <http://feministing.com/2015/02/03/how-using-they-as-a-singular-pronoun-can-c...>