minimal_django_env.py

# See: https://github.com/joke2k/django-environ/blob/v0.4.1/environ/environ.py#L48
class NoValue(object):

    def __repr__(self):
        return '<{0}>'.format(self.__class__.__name__)


# https://github.com/joke2k/django-environ/blob/v0.4.1/environ/environ.py#L67
NOTSET = NoValue()


def env(env_var, default=NOTSET):
    """
    Tiny os.environ wrapper to DRY-up env / error handling.

    The api here is a basic version of django.environ in preperation
    for refactoring to that library permanently.

    Raises djnago.core.execptions.ImproperlyConfigured
        if no default is specified.

    Kwargs:
    default  -- The default value to return if var is not set (default None)
    """
    try:
        return os.environ[env_var]
    except KeyError as e:
        if default is NOTSET:
            error_msg = "{} is a required env setting but is not set!".format(env_var)
            raise ImproperlyConfigured(error_msg)
        else:
            return default
    except Exception as e:
        print "Caught unhandled exception while accessing os.environ, {}".format(e.message)
        raise