[Python-ideas] Subprocess: Add an encoding argument

[Paul Moore]

On 30 August 2014 12:07, Antoine Pitrou <solipsis at pitrou.net> wrote:
> On Fri, 29 Aug 2014 18:39:35 +1000
> Nick Coghlan <ncoghlan at gmail.com> wrote:
>>
>> This actually gets a little messy once you start digging into it, as you
>> actually have up to 3 streams to deal with (stdin, stdout, stderr), and may
>> want to set the error handler in addition to the encoding.
>
> At this point, I'd suggest creating a clean, separate TextPopen class
> (or subclass) without any legacy argument baggage.
>
> As for per-stream settings, we could allow passing each of *encoding*
> and *errors* in two forms:
> - as a string, in which case it applies to all three pipes
> - as a dict, in which case it is looked up for each of the "stdin",
>   "stdout", "stderr" pipes (if configured as pipes)
>
> We could then deprecate the bogus-named "universal_newlines" in the
> main Popen class.

Sounds reasonable. I'll look into that (no promises on timescales :-))
In practice, I doubt we'd need per-stram encodings particularly often,
so I like the idea of *not* clutteringthe API to cope with them. I'm
curious, by the way - what arguments do you consider as "legacy
baggage" (a lot of them seem to me to be OS-specific and/or
specialised rather than legacy).

In practice, we'd probably need to do something about the utility
functions like check_output and communicate as well.
Paul