Python 2.7 compatibility? about hpc-container-maker

[samcmill]

At first glance:

• enums are a minor annoyance with Python 2.7 since they are not default, but not a big deal to install the enum package.
• shlex.quote() looks like it can be handled by six
• subprocess.DEVNULL can probably be replaced by os.devnull.
• Will need to take a closer look at raise e from e. This was added to support --print-exceptions, which was a user requested feature.

[boegel]

@samcmill Hmm, relying on six to resolve the shlex.quote issue seems overkill to me, assuming we're OK with compatibility with only Python 2.7 and 3.3 or newer, since in Python 2.7 we can use pipes.quote instead, cfr. https://stackoverflow.com/a/26791164/1467322 ?

[samcmill]

My impression, perhaps incorrect, is that pipes.quote is deprecated in Python 3 and may be removed at any time. https://docs.python.org/3/library/pipes.html does not mention it, although it's (indirectly) available in the implementation https://github.com/python/cpython/blob/3.6/Lib/pipes.py due to from shlex import quote.

[boegel]

@samcmill I wasn't suggesting to switch to pipes.quote, but rather to use a construct like:

try:
    from shlex import quote  # python 3.3
except ImportError:
    from pipes import quote  # python 2.7

[samcmill]

Closing. Resolved with merge #28.