'Load the settings module pointed to by the environment variable. This
is used the first time we need any settings at all, if the user has not
previously configured the settings manually.'

def _setup(self, name=None):

    try:
        settings_module = os.environ[ENVIRONMENT_VARIABLE]
        if (not settings_module):
            raise KeyError
    except KeyError:
        desc = (('setting    %s' % name) if name else 'settings')
        raise ImproperlyConfigured(('Requested    %s,    but    settings    are    not    configured.    You    must    either    define    the    environment    variable    %s    or    call    settings.configure()    before    accessing    settings.' % (desc, ENVIRONMENT_VARIABLE)))
    self._wrapped = Settings(settings_module)
    self._configure_logging()
