Doctesting argparse with multiprocessing / multiprocessing で argparse の doctest を書く

forked_argparse_test

"""
>>> from argparse import ArgumentParser
>>> from multiprocessing import Process, Queue
>>> def build_parser():
...     parser = ArgumentParser()
...     parser.add_argument('-e', '--engage', action='store_true')
...     parser.add_argument('-b', '--beam-me-up', action='store_true')
...     parser.add_argument('-d', '--good-day-to-die', action='store_true')
...     # blah blah blah
...     return parser
...
>>> def task(args, tx_queue, ns_queue):
...     parser = build_parser()
...     def queue_message(message, file=None):
...         tx_queue.put(message)
...     parser._print_message = queue_message
...     ns = parser.parse_args(args)
...     ns_queue.put(ns._get_args())
...     ns_queue.put(ns._get_kwargs())
...
>>> def do_forked_test(args):
...     tx_queue, ns_queue = Queue(), Queue()
...     proc = Process(target=task, args=(args, tx_queue, ns_queue))
...     proc.start(); proc.join()
...     while not tx_queue.empty():
...         print tx_queue.get()
...     args = [] if ns_queue.empty() else ns_queue.get()
...     kwargs = [] if ns_queue.empty() else ns_queue.get()
...     tx_queue.close(), ns_queue.close()
...     return (proc.exitcode, args, kwargs)
...
>>> do_forked_test([])
(0, [], [('beam_me_up', False), ('engage', False), ('good_day_to_die', False)])
>>> do_forked_test(['-h'])
usage: [-h] [-e] [-b] [-d]
<BLANKLINE>
optional arguments:
  -h, --help            show this help message and exit
  -e, --engage
  -b, --beam-me-up
  -d, --good-day-to-die
<BLANKLINE>
(0, [], [])
>>> do_forked_test(['-x'])
usage: [-h] [-e] [-b] [-d]
<BLANKLINE>
: error: unrecognized arguments: -x
<BLANKLINE>
(2, [], [])
"""

if __name__=='__main__':
    from doctest import testmod
    testmod()