<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _get_url_path(list_name):
 """ Live Dao requires RESTCLIENTS_MAILMAN_KEY in the settings.py """

    access_key = getattr(settings,
                         "RESTCLIENTS_MAILMAN_KEY",
                         "__mock_key__")
    return URL.format(key=access_key, uwnetid=list_name)