docs: def get_qiniu_config(name, default=None):
      """
      Get configuration variable from environment variable
      or django setting.py
      """
      config = os.environ.get(name, getattr(settings, name, default))
      if config is not None:
          if isinstance(config, six.string_types):
              return config.strip()
          else:
              return config
      else:
          raise ImproperlyConfigured(
              "Can't find config for '%s' either in environment"
              "variable or in setting.py" % name)