如何标记学生在场/缺席python

Question

I am trying to mark users present/absent based on their last login timestamp. If the users logged in on 9/3/2020 at midnight and before 9:05am they are marked present otherwise they are absent.

Student Timestamp example

Time                            Present/Absent
2020-09-03T08:55:14-05:00          present
2020-09-03T04:44:46-05:00          present
2020-09-03T09:01:05-05:00          present
2020-09-03T07:12:22-05:00          present
2020-09-03T08:48:53-05:00          present
2020-09-02T16:53:20-05:00          absent
2020-09-02T20:02:28-05:00          absent
2020-09-03T09:01:15-05:00          present
2020-09-03T08:55:03-05:00          present
2020-09-03T09:03:03-05:00          present
2020-09-02T09:13:32-05:00          absent
2020-09-02T23:24:54-05:00          absent
2020-09-02T23:24:58-05:00          absent
2020-09-03T09:03:03-05:00          present
2020-09-02T23:25:01-05:00          absent

This is my code

df3['Time'] = df3['Time'].astype(str)

for time in df3['Time']:
    if time > '%Y-%m-%d 00:00:00-05:00':
        df3['Present/Absent'] = 'absent'
    elif  time < '%Y-%m-%d 09:05:00-05:00':
        df3['Present/Absent'] = 'present'

but I get this

Time                        Present/Absent
2020-09-03T08:55:14-05:00     present
2020-09-03T04:44:46-05:00     present
2020-09-03T09:01:05-05:00     present
2020-09-03T07:12:22-05:00     present
2020-09-03T08:48:53-05:00     present
2020-09-02T16:53:20-05:00     present
2020-09-02T20:02:28-05:00     present
2020-09-03T09:01:15-05:00     present
2020-09-03T08:55:03-05:00     present
2020-09-03T09:03:03-05:00     present
2020-09-02T09:13:32-05:00     present
2020-09-02T23:24:54-05:00     present
2020-09-02T23:24:58-05:00     present
2020-09-03T09:03:03-05:00     present
2020-09-02T23:25:01-05:00     present

Answer 1

df3['Present/Absent'] = 'present' is assigning 'present' to the entire column. Same applies for the 'absent' condition as well. Try this:

df3['Time'] = df3['Time'].astype(str)
df3['Present/Absent'] = ''
for idx, row in df3.iterrows():
    time = row['Time']
    if time > '%Y-%m-%d 00:00:00-05:00':
        df3.loc[idx, 'Present/Absent'] = 'absent'
    elif  time < '%Y-%m-%d 09:05:00-05:00':
        df3.loc[idx, 'Present/Absent'] = 'present'

I'm assuming the condition is working as expected and df3 is similar to Student Timestamp example.