The code below is faulty - mypy correctly emits an error "Too many arguments for "set_log_level"":

class LoggableDB:
    def set_log_level(v):
        print(type(v).__name__)

LoggableDB().set_log_level("i am not myself")

Pitch

With the code being faulty, it needs to be fixed by a developer.

The most ergonomic approach is telling the developer about a most likely fix. Therefore, it would be helpful to enrich the output with a nudging diagnostic (hint, warning) to the effect of "<method> is missing a parameter named self as the first parameter" would be appreciated.

I believe that having this diagnostic would reduce mental effort and accelerate development, by allowing a developer to merely read, without having to spend too many brain cycles.

Additionally, the added nudge would be at the location of the real problem (missing self) as opposed to being only at the call site. Depending on the distance between definition and caller, that additional nudge might accelerate the fix.

This nudging hint would be valuable both during interactive use (in an editor) and in batch mode (CI).

Hiding this nudge behind a config switch would alleviate any challenges where developer have not followed / do not want to follow the convention of naming that first parameter self