pydoc contains these two functions that could be used by third-party code to implement a custom dir function, write a documentation tool or other uses: visiblename and allmethods.  We could make them public, in pydoc or inspect.

Copied from msg143857:

> There are a lot of little internal routines in the standard library
> that aren't sufficiently fit to be exposed (perhaps a little too
> ad-hoc or special purpose, perhaps the API isn't sufficiently
> general, perhaps the routines rely on non-guaranteed aspects of the
> implementation).  For example, visiblename() is more heuristic than
> algorithmic -- right now, we can change that as needed (for instance,
> the recent updates to accommodate named tuples), but as soon as the
> method or function becomes public, its API freezes and it is hard for
> us to make changes.

I agree with your general point.  For this particular case, I’d be okay if you wanted to reject the request.  Users can filter the output of dir depending on their needs (_private names, __magic__ names, etc.).  For more useful code (that can cope with named tuples for example), I think generic functions would be a nice way to do this.

A precision:

> I think generic functions would be a nice way to do this.
I meant: a nice way to experiment this *outside of the stdlib*.  We don’t have official generic function yet, so I’ll wait to see if pprint gets rewritten and/or if we get a generic functions PEP and standard module.

Sorry if these issues I opened are consuming your time; I wanted to make sure we considered the proposals separately and add a good rationale for rejecting them.  Thanks for weighing in.