From the Docs mailing list:

>Hi

>I found a bug in python docs which can be accessed at links:
>http://docs.python.org/library/threading.html#lock-objects
>http://docs.python.org/py3k/library/threading.html#lock-objects

>Bug is in second paragraph describing threading.Lock. I found that >statement:
>"If an attempt is made to release an unlocked lock, a RuntimeError will >be raised."
>Which is not true, name of exception is wrong it should be (and it >relay is) ThreadError (from threading module)

>Could someone fix it?

>-- 
>Br,
>Slawomir Kuszczynski

Working on a patch now unless there are objections to the OP.

The problem is: threading.Lock raises ThreadingError (which is subclass of RuntimeError for 3.3 but not for 3.2), but threading.Condition raises RuntimeError for the same reason.

RLock behavior is even worse: it raises ThreadingError if C accelerator is available in _thread and RuntimeError otherwise.

I think RuntimeError should be replaced by ThreadingError for _RLock and Condition implementations as well as docs need to be updated.

Also I think this patch should be applied to 3.4 only, it is enchacement, not bugfix.
About fixing docs for 2.7-3.3: I see nothing wrong if current inconsistency will be documented, perhaps as *warning* or *note* block.

>>I think RuntimeError should be replaced by ThreadingError for _RLock >>and Condition implementations as well as docs need to be updated.
>>
>>Also I think this patch should be applied to 3.4 only, it is >>enchacement, not bugfix.
>>About fixing docs for 2.7-3.3: I see nothing wrong if current >>inconsistency will be documented, perhaps as *warning* or *note* block.

I should warn that ThreadError or `ThreadError` has no link. I've tried to find a place in the docs I could link to but haven't yet. `ValueError` does have a link.

ValueError can be referenced by :exc:`ValueError`.
For ThreadError you can add section for describing this exception type like:

.. exception:: ThreadError

    Raised when lock object cannot be acquired or released.

I discussed this in IRC and got the following information from Ezio:

< Taggnostr> the doc fix can go in 2.7/3.3, the code fix in 3.4

Plan is to put the definition for ThreadError in threading.rst for both 2.7 and 3.3

Sounds good.

3.3 patch

2.7 patch.

Please see Issue 14502.  The docs probably do need clarification, but it must be done carefully.

New changeset d7e9c0a6dbcf by Georg Brandl in branch '2.7':
Closes #15829: document ThreadError and fix exception raised for releasing unlocked locks.
http://hg.python.org/cpython/rev/d7e9c0a6dbcf

3.3 didn't need to be updated; it's RuntimeError there everywhere.