>>> from os import *
>>> fdopen
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'fdopen' is not defined

While this is technically probably a bug, I'm -0 on fixing it in bugfix releases, as it has the risk of breaking working code.

I think this came in when we moved os.fdopen and os.popen from native C code to Python code in http://hg.python.org/cpython/rev/1f7891d84d93.  This works fine in 2.7.  The same issue exist with os.popen, but that is deprecated.

> While this is technically probably a bug, I'm -0 on fixing it in bugfix
> releases, as it has the risk of breaking working code.

I don't feel strongly about in which release this should be fixed, but
can you give me an example of how it could break working code?

> can you give me an example of how it could break working code?

This is a bit contrived, but:

# my fdopen
def fdopen(fd):
    pass

fdopen(1)

# some stuff

from os import *

# more stuff

fdopen(1)

Here is a patch for 3.3 tip.  After reviewing the 'os' module documentation I found a few more cases.

Perhaps a little less contrived

from libc_wrapper import fdopen
from os import *

where libc_wrapper might be a module built on top of ctypes.

I found two more: P_NOWAITO and _exit. Attached an updated patch.

New changeset 352147bbefdb by Petri Lehtinen in branch 'default':
#14862: Add missing names to os.__all__
http://hg.python.org/cpython/rev/352147bbefdb