On Thu, Sep 5, 2019 at 2:07 AM Israel Brewster <ijbrews...@alaska.edu> wrote: > > > > > On Sep 3, 2019, at 11:09 AM, Israel Brewster <ijbrews...@alaska.edu> wrote: > > > >> > >> On Sep 3, 2019, at 10:49 AM, Peter Otten <__pete...@web.de> wrote: > >> > >> 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) > > > > That looks like exactly what I was looking for. I’ll give it a shot. Thanks! > > So as it turns out, this doesn’t work after all. I get an error stating that > “Queue objects should only be shared between processes through inheritance”. > Still a good technique to know though! >
Globals aren't as bad as some people think. In this case, a module-level variable seems like the correct way to do things. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
