I broke help() for instances of these context managers by trying to postpone exposing the class APIs until 3.5 (and didn't even record my full rationale, however flawed, in the associated comments).

The wrapper functions should be removed, making the classes the public implementation. I also plan to make the following changes (although I may end up moving them to separate issues):

- provide (and document) a public "target" attribute on redirect_stdout
- make redirect_stdout reentrant (and switch to ExitStack as the reusable-but-not-reentrant example)

- provide (and document) a public "exceptions" attribute on suppress
- return self from suppress.__enter__

I decided to defer adding any public attributes to these APIs - that greatly simplifies this patch, is more consistent with the draft wording in the PEP 8 update (issue 19331), and if the demand for improved introspection support is there, we can always add them for 3.5.

I checked the other classes in contextlib to ensure they also provided decent docstrings on instances. They were mostly OK, but @contextmanager itself doesn't provide useful docs when inspecting the result context manager instances directly. However, fixing that isn't trivial: see issue 19404 for details.

New changeset 09153a9a3bb9 by Nick Coghlan in branch 'default':
Close #19330 by using public classes in contextlib
http://hg.python.org/cpython/rev/09153a9a3bb9

I suppose tests will fail when Python is compiled with --without-doc-strings options. Perhaps the test.support.requires_docstrings decorator should be used.

It also fails under -OO, so I changed that decorator to deal with that case as well.

New changeset a9bbc2d0c1dc by Nick Coghlan in branch 'default':
Issue #19330: Handle the no-docstrings case in tests
http://hg.python.org/cpython/rev/a9bbc2d0c1dc