Daily Life in an Ivory Basement

After an innocent question was answered positively, I am putting together a patch to deprecate the commands module in favor of a slightly expanded subprocess module (for 2.6).

Briefly, the idea is to add three new functions to subprocess:

output = get_output(cmd, input=None, cwd=None, env=None):

(status, output) = get_status_output(cmd, input=None, cwd=None, env=None)

(status, output, errout) = get_status_output_errors(cmd, input=None, cwd=None, env=None)

with the goal of replacing commands.getstatusoutput and commands.getoutput. (commands.getstatus has already been removed from 2.6.)

This will provide a simple set of functions for some very common subprocess use-cases, as well as providing for a cross-platform alternative to commands, with better post-fork behavior and error trapping, adhering to PEP 8coding standards. A win-win-win, I hope ;).

In addition to writing the basic code & some tests, I would like to:

• reorganize, correct, and expand the subprocess documentation: right now it's not as useful as it could be.
• put some warnings/error reporting into subprocess for bad class parameters; e.g. Popen.communicate should check to be sure both subprocess.stdout and stderr are PIPEs.

Questions:

• anything else I should think about doing to subprocess?
• right now the functions take only the input, cwd, and env arguments to pass through to the Popen constructor. Any other favorite arguments out there?
• should language be added to the popen2 module pointing people at subprocess, and should popen2 be deprecated?
• GvR suggested that I reimplement commands in terms of these subprocess functions for 2.6, even though the commands module could be deprecated in 2.6 and probably removed in 2.7. I would rather simply amend the documentation to point people at subprocess.

Thoughts?

--titus

p.s. The implementation of the above functions is dead simple:

def get_status_output(cmd, input=None, cwd=None, env=None):
    pipe = Popen(cmd, shell=True, cwd=cwd, env=env, stdout=PIPE, stderr=STDOUT)

    (output, errout) = pipe.communicate(input=input)
    assert not errout

    status = pipe.returncode

    return (status, output)

def get_status_output_errors(cmd, input=None, cwd=None, env=None):
    pipe = Popen(cmd, shell=True, cwd=cwd, env=env, stdout=PIPE, stderr=PIPE)

    (output, errout) = pipe.communicate(input=input)

    status = pipe.returncode

    return (status, output, errout)

def get_output(cmd, input=None, cwd=None, env=None):
    return get_status_output()[1]