Inconsistent behavior:
pydoc3 str: works
pydoc3 str.translate: doesn’t
pydoc3 builtins.str: works
pydoc3 builtins.str.translate: doesn’t

I think pydoc3 str.translate should work. I’ll be able to try to write a patch in some weeks.

Note that

>>> help(str.translate)
Help on method_descriptor:

translate(...)
    S.translate(table) -> str
    
    Return a copy of the string S, where all characters have been mapped
..

but
>>> help('str.translate')
no Python documentation found for 'str.translate'

Yep, same bug.

Possibly related: #410336 (I have to read it again to make sure).

Turns out the fix is very simple.  Please review.

The patch looks good.  A nit-pick:

+        if len(parts) > 0:

Since *parts* is a list, the above can be replaced with simply "if parts:".

Also, it seems to me that the new code may produce an AttributeError when given invalid name, but locate() function is supposed to return None instead.

I wouder if it would be possible to reuse the try/except logic ing the "if module" clause and simply do something like

    if module:
        object = module
    else:
        object = builtins
    for part in parts[n:]:
        try:
            object = getattr(object, part)
        except AttributeError:
            return None
    return object

> Since *parts* is a list, the above can be replaced with simply "if parts:"

Heh, I always use implied truth values and one disagreed with Tarek about this, but here if felt more natural to spell out my mind with an explicit > 0 comparison :)

> Also, it seems to me that the new code may produce an AttributeError
> when given invalid name

I didn’t see that, I forgot to test invalid names, since test_pydoc already has some checks.  I’ll add tests and see if I can reproduce what you’re hinting at (it would be helpful if you could give examples of invalid names: full dotted names, method names, class names?).

> I wouder if it would be possible to reuse the try/except logic ing
> the "if module" clause

Sure, as long as the tests pass I have no preference about the implementation.  BTW, what’s your opinion on the test I added?  I use render_doc to test name resolving, do you think I should also test the command-line pydoc in a subprocess or is it okay to have white-box knowledge here?

On Fri, May 27, 2011 at 12:23 PM, Éric Araujo <report@bugs.python.org> wrote:
> .. I’ll add tests and see if I can reproduce what you’re hinting at (it would be helpful
> if you could give examples of invalid names: full dotted names, method names, class names?).

I did not try to apply your patch yet, but what I had in mind was
misspelled names like "str.transkate".

I added tests to cover non-existing attributes and updated the code to follow your clever suggestion.

New changeset 68df566cbf92 by Éric Araujo in branch '2.7':
Make “pydoc somebuiltin.somemethod” work (#8887)
http://hg.python.org/cpython/rev/68df566cbf92

New changeset f02a8f906342 by Éric Araujo in branch '3.2':
Make “pydoc somebuiltin.somemethod” work (#8887)
http://hg.python.org/cpython/rev/f02a8f906342

New changeset 91d6cabf77d6 by Éric Araujo in branch 'default':
Merge fix for #8887 from 3.2
http://hg.python.org/cpython/rev/91d6cabf77d6

Thanks again for the useful review.