def latest_stable_version(get):
    metadata = loads(get(
        environ.get('LE_AUTO_JSON_URL',
                    'https://pypi.python.org/pypi/letsencrypt/json')))
    # metadata['info']['version'] actually returns the latest of any kind of
    # release release, contrary to https://wiki.python.org/moin/PyPIJSON.
    # The regex is a sufficient regex for picking out prereleases for most
    # packages, LE included.
    return str(max(LooseVersion(r) for r
                   in metadata['releases'].iterkeys()
                   if re.match('^[0-9.]+$', r)))
Get the mail notification service.
dataset/ETHPy150Open letsencrypt/letsencrypt/letsencrypt-auto-source/pieces/fetch.py/latest_stable_version--crossover with--dataset/ETHPy150Open home-assistant/home-assistant/homeassistant/components/notify/smtp.py/get_service