使用新列修改数据框

Question

I have the below data frame called df_test that I want to modify and create 4 new columns based on existing values for each id.

#df_test
date            event id         time
17/01/2020      1     596471930  10:18:37
17/01/2020      2     596471930  10:32:48
17/01/2020      3     596471930  12:42:01
17/01/2020      4     596471930  12:44:03

In this example, I want to modify the df_test to display values for all events this way.

date        id         dateTime event 1     dateTime event 2     dateTime event 3     dateTime event 4
17/01/2020  596471930  17/01/2020 10:18:37  17/01/2020 10:32:48  17/01/2020 12:42:01  17/01/2020 12:44:03

Here is the code for the df_test.

import pandas as pd
test = {'date': ['17/01/2020','17/01/2020','17/01/2020','17/01/2020'],
        'event': [1,2,3,4],
        'id': [596471930,596471930,596471930,596471930],
        'time': ['10:18:37','10:32:48','12:42:01','12:44:03']
        }
df_test = pd.DataFrame(test, columns = ['date', 'event', 'id', 'time'])

Answer 1

尝试pivot_table ：

pd.pivot_table(df_test, values='time', index=['date', 'id'],columns=['event'],aggfunc='first')