def __len__(self):
        if self._activity_ids:
            length = len(self.activity_ids)
        else:
            length = len(self.activities)
        return length
Initialize logger instance.
dataset/ETHPy150Open tschellenbach/Stream-Framework/stream_framework/activity.py/AggregatedActivity.__len__--crossover with--dataset/ETHPy150Open seb-m/pyinotify/python2/pyinotify.py/logger_init