2.4isms for bzr

[John A Meinel]

Aaron Bentley wrote:
> John A Meinel wrote:
> 
>>>I agree that having communicate be one time is a little bit of a pain,
>>>but I think it is for simplicity, and the fact that a lot of times, that
>>>is all you need.
> 
> 
> Sure, it's just that everyone says subprocess is the greatest thing
> since sliced wheels, and this seems like an oversight.

Mmmmm, sliced wheels, droool. :)

Actually, subprocess is a vast improvement over all of the popen 
functionality, especially if you want cross platform compatiblility 
(since the Popen3,4 classes don't exist in Windows).

but yes, I have often wished that something like communicate was re-entrant.


> 
> 
>>>And it depends what you mean by "efficient", because your above code
>>>just buffers everything in ram, which is what communicate does.
> 
> 
> It doesn't require you to generate one big string for stdin-- it can be
> an iterator, which is more eficient.  You can also imagine writing an
> iterator that yields stdout and does something else with stderr.  Or
> yields stderr and writes stdout to disk.  Endless possibilities for
> efficient handling!
> 
> 
>>>Heck, make iter_communicate support having input being a generator, and
>>>you could even have bi-directional communications with another process,
>>>while having it only really look like a loop.
> 
> 
> Exactly the kind of thing I mean.  Especially if 2.5 introduces
> iterators with send() (which is under discussion), it would be criminal
> not supporting this mode of operation.

Sure. Hopefully, if 2.5 does handle the re-entrant yield gives a value 
iterators, subprocess will be updated to support this.
Certainly their examples show "data = yield nonblocking_read(sock)" 
which would be what you want for pipes to do nice ipc.

> 
> Aaron

John
=:->
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