text_plain_output_1.png
import numpy as np

import pandas as pd

print('# Read App Events')
app_ev = pd.read_csv('../input/app_events.csv', dtype={'device_id': np.str})
app_ev = app_ev.groupby('event_id')['app_id'].apply(lambda x: ' '.join(set(('app_id:' + str(s) for s in x))))