On 30Apr2009 22:57, MRAB <goo...@mrabarnett.plus.com> wrote:
> Luis Zarrabeitia wrote:
>> The problem: when there is no more data to process, how can I signal
>> the consumers to consume until the queue is empty and then stop
>> consuming? I need them to do some clean-up work after they finish (and
>> then I need the main script to summarize the results)
[...]
>> As you can see, I'm sending one 'None' per consumer, and hoping that no
>> consumer will read more than one None. While this particular
>> implementation ensures that, it is very fragile. [...]
>>
> The producer could send just one None to indicate that it has finished
> producing.
>
> Each consumer could get the data from the queue, but if it's None then
> put it back in the queue for the other consumer, then clean up and
> finish.
>
> When all the consumers have finished, the queue will contain just the
> single None.
And as it happens I have an IterableQueue class right here which does
_exact_ what was just described. You're welcome to it if you like.
Added bonus is that, as the name suggests, you can use the class as
an iterator:
for item in iterq:
...
The producer calls iterq.close() when it's done.
I'll clean up the formatting and add a bunch of missing docstrings if
anyone wants it...
Cheers,
--
Cameron Simpson <c...@zip.com.au> DoD#743
http://www.cskk.ezoshosting.com/cs/
Indeed! But do not reject these teachings as false because I am crazy. The
reason that I am crazy is because they are true.
- Malaclypse the Younger
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