cli_invoker.py

#!/usr/bin/env python3

"""
python3.5+ ( uses subprocess.run(), added in 3.5 )

USAGE:

>>> from cli_invoker import COMMAND, invoke
>>> cmd = COMMAND.globus('-F', 'JSON')
>>> invoke(cmd.whoami)
>>> invoke(cmd.ls('ddb59aef-6d04-11e5-ba46-22000b92c6ec'))

To print output from such a handle, it's just a CompletedProcess, so...

>>> print(invoke(COMMAND.ls).stdout.decode('unicode_escape'))

Something fancy:

>>> print(invoke(COMMAND.globus.task.list(
...     '-F', 'unix',
...     '--jmespath', 'DATA[*].[status, type, label]')
...              ).stdout.decode('unicode_escape'))
"""

import subprocess


class _CMD(object):
    def __init__(self, args):
        self._args = args

    def __call__(self, *args):
        return _CMD(self._args + list(args))

    def __getattr__(self, attrname):
        return _CMD(self._args + [attrname])

    def __repr__(self):
        return str(self._args)


COMMAND = _CMD([])


def invoke(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, **kwargs):
    return subprocess.run(
        cmd._args,
        stdout=stdout, stderr=stderr, **kwargs)