Pandas get max DateTime per day

Question

Team, I have a simple dataframe with 2 columns(Datetime, Duration), Need to find what is the value of Duration on max Datetime value for each day. Below is the sample data for the dataframe

starttime             Duartion
2021-07-17 03:30:00   1234
2021-07-17 07:30:00   498
2021-07-18 03:30:00   1700
2021-07-18 07:40:00   2185

o/p

starttime             Duartion
2021-07-17 07:30:00   498
2021-07-18 07:40:00   2185

Any help on this please.

have a look at https://stackoverflow.com/questions/15705630/get-the-rows-which-have-the-max-value-in-groups-using-groupby — balderman, Sep 27 '21 at 13:48

score 1 · Accepted Answer · answered Sep 27 '21 at 13:55

1

Pre-requisite, using datetime type for "starttime":

df['starttime'] = pd.to_datetime(df['starttime'])

If the "starttime" values are already sorted:

df.groupby(df['starttime'].dt.normalize(), as_index=False).last()

else:

df.loc[df.groupby(df['starttime'].dt.normalize())['starttime'].idxmax().values]

answered Sep 27 '21 at 13:55

mozway

194,879
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Thanks mozway.. Appreciate your help – Prakash Sep 27 '21 at 14:49

score 0 · Answer 2 · answered Sep 27 '21 at 13:53

0

This will take the maximum value per day:

df.set_index('starttime').resample('1D').max()

answered Sep 27 '21 at 13:53

vtasca

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he doesn't want the max `Duartion` but the `Duartion` for the max `starttime` per day – luigigi Sep 27 '21 at 13:55

Pandas get max DateTime per day

2 Answers2