def event_answers(event_id):
    """Return a dict mapping {"yes","no","maybe"} onto (username, num_guests) pairs."""
    answers = defaultdict(list)
    rsvps = meetup("2/rsvps", event_id=event_id)
    for rsvp in rsvps:
        answers[rsvp['response']].append((rsvp['member']['name'], rsvp['guests']))
    return answers

def list_events(**kwargs):
    """Return a list of events, from the 2/events Meetup API call."""
    kwargs.setdefault('group_id', GROUP_ID)
    events = meetup("2/events", **kwargs)
    for event in events:
        event['when'] = time.strftime("%d %b %Y", time.localtime(event['time']//1000))
    return events

def event_attendees(event_id):
    """Return the set of attendees in the yes or waiting list."""
    rsvps = meetup("2/rsvps", event_id=event_id)
    attendees = set()
    for rsvp in rsvps:
        if rsvp['response'] in ['yes', 'waitlist']:
            member = rsvp['member']
            attendees.add((member['member_id'], member['name']))
    return attendees

def group_members(**kwargs):
    """Return a list of the members of a group."""
    members = meetup.meetup("members", **kwargs)
    for m in members:
        last_visit = time.strptime(m['visited'][:-4], "%Y-%m-%d %H:%M:%S")
        m['visitage'] = time.time() - time.mktime(last_visit)
        joined = time.strptime(m['joined'].replace("EDT ", "").replace("EST ", ""), "%a %b %d %H:%M:%S %Y")
        m['joinage'] = time.time() - time.mktime(joined)
        all_names.add(m['name'].lower())
        gend = guess_gender(m['name'])
        if gend not in ['male', 'female']:
            unknown_names.add(m['name'].lower())
            gend = "unknown"
        m['gender'] = gend
    return members