[Python-ideas] Subprocess: Add an encoding argument

[Nick Coghlan]

On 2 September 2014 07:15, Paul Moore <p.f.moore at gmail.com> wrote:
> The find -print0 example is out of scope, IMO, as newline handling is
> different from encoding. At some point, it becomes easier to manually
> wrap the streams rather than having huge numbers of parameters to the
> Popen constructor.

Don't forget Antoine's suggestion of creating a TextPopen subclass
that wraps the streams as strict UTF-8 by default and allows the
encoding and errors arguments to be either strings (affecting all
pipes) or a dictionary mapping "stdin", "stdout" and "stderr" to
individual settings.

With that, the simple utf-8 example just becomes:

  with TextPopen(cmd, stdout=PIPE) as p:
      for line in p.stdout:
          process(line)

> I'll think some more on this...

For your torture test, consider the "iconv" (or "win_iconv") utility,
which does encoding conversions, and how you might test that from a
Python program without needing to do your own encoding and decoding,
but instead let the subprocess module handle it for you :)

(There's a flip side to that problem which is the question of
*writing* an iconv utility in Python 3, and that's why there's an open
RFE to support changing the encoding of an existing stream)

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at gmail.com   |   Brisbane, Australia