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Proper way to pass Queue to process when using multiprocessing.imap()?


Israel Brewster wrote:

> When using pool.imap to apply a function over a list of values, what is
> the proper way to pass additional arguments to the function, specifically
> in my case a Queue that the process can use to communicate back to the
> main thread (for the purpose of reporting progress)? I have seen
> suggestions of using starmap, but this doesn?t appear to have a ?lazy?
> variant, which I have found to be very beneficial in my use case. The
> Queue is the same one for all processes, if that makes a difference.
> 
> I could just make the Queue global, but I have always been told not too.
> Perhaps this is an exception?

How about wrapping the function into another function that takes only one 
argument? A concise way is to do that with functools.partial():

def f(value, queue): ...

pool.imap(partial(f, queue=...), values)



>  
> ---
> Israel Brewster
> Software Engineer
> Alaska Volcano Observatory
> Geophysical Institute - UAF
> 2156 Koyukuk Drive
> Fairbanks AK 99775-7320
> Work: 907-474-5172
> cell:  907-328-9145
>