text_html_output_1.png
import pandas as pd # data processing, CSV file I/O (e.g. pd.read_csv)

train = pd.read_csv('../input/act_train.csv', parse_dates=['date'])
test = pd.read_csv('../input/act_test.csv', parse_dates=['date'])
ppl = pd.read_csv('../input/people.csv', parse_dates=['date'])
df_train = pd.merge(train, ppl, on='people_id')
df_test = pd.merge(test, ppl, on='people_id')
del train, test, ppl

for d in ['date_x', 'date_y']:
    print('Start of ' + d + ': ' + str(df_train[d].min().date()))
    print('  End of ' + d + ': ' + str(df_train[d].max().date()))
    print('Range of ' + d + ': ' + str(df_train[d].max() - df_train[d].min()) + '\n')