[docs] [issue32306] Clarify map API in concurrent.futures

[David Lukeš]

David Lukeš <dafydd.lukes at gmail.com> added the comment:

Hi Antoine,

Thanks for the response! :) I think the problem lies in the line immediately preceding the code you've posted:

```
fs = [self.submit(fn, *args) for args in zip(*iterables)]
```

In other words, all the jobs are first submitted and their futures stored in a list, which is then iterated over. This approach obviously breaks down when there is a great number of jobs, or when it's part of a pipeline meant for processing jobs continuously as they come.

----------

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue32306>
_______________________________________