def presence_start_end_view(user_id):
    """
    Returns mean time of presence.
    """
    data = get_data()
    if user_id not in data:
        log.debug('User %s not found!', user_id)
        abort(404)

    mean_times = mean_time_of_presence(data[user_id])
    result = [
        (calendar.day_abbr[weekday], mean_times[value])
        for weekday, value in enumerate(mean_times)
    ]
    return result
 def test_mean_time_of_presence(self):
     """
     Test calculating mean entries for every weekday.
     """
     sample_data = utils.get_data()
     result = utils.mean_time_of_presence(sample_data[10])
     self.assertDictEqual(
         result,
         {
             0: {'start': 0, 'end': 0},
             1: {'start': 34745.0, 'end': 64792.0},
             2: {'start': 33592.0, 'end': 58057.0},
             3: {'start': 38926.0, 'end': 62631.0},
             4: {'start': 0, 'end': 0},
             5: {'start': 0, 'end': 0},
             6: {'start': 0, 'end': 0}
         }
     )