On 12/6/2011 2:13 PM, John Ladasky wrote:
Exception in thread Thread-1:
Traceback (most recent call last):
File "/usr/lib/python2.6/threading.py", line 532, in
__bootstrap_inner
self.run()
File "/usr/lib/python2.6/threading.py", line 484, in run
self.__target(*self.__args, **self.__kwargs)
File "/usr/lib/python2.6/multiprocessing/pool.py", line 225, in
_handle_tasks
put(task)
TypeError: expected string or Unicode object, NoneType found
=============================================
Here's what I think would help me debug this error: I would like to
catch the TypeError, and examine the contents of task.
The traceback says that it is None, which has no contents ;=).
I need to
accomplish this WITHOUT adding a try...except block to the Python
library file multiprocessing/pool.py.
I do not understand this statement. You should feel free to make a
backup copy of pool.py and then modify it for debugging.
> I don't know whether this is
possible, because the traceback isn't clear about where my OWN code
calls the code which is generating the error.
It appears to be threading trying to call your code, and failing, that
is the problem. But I do not know how threading, multiprocessing.pool,
and your code are supposed to interact.
After that, if the cause of the error still is not obvious, I might
need to go back to the working program. Somehow I want to examine the
contents of task when the program works, and no TypeError is being
generated.
The traceback says that it is a string.
I would start with the line that fails 'put(task)', and work backwards
to see where 'task' comes from and how it could become None. It is even
possible that multiprocessing.pool has a bug that you ran into.
--
Terry Jan Reedy
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