How do I replace specific times in pandas column that is datetime format? I need to replace all times of 23:52:00
with 23:59:59
in df.end
data = [['site a', '2021-03-05 23:52:00'],
['site a', '2021-03-06 12:00:00'],
['site b', '2021-04-08 23:00:00'],
['site c', '2021-04-09 23:52:00']]
df = pd.DataFrame(data, columns = ['id', 'end'])
df['end'] = pd.to_datetime(df['end'], infer_datetime_format=True)
Using this where statement, none of the times change. this due to this statement: df['end'].dt.time == '23:52:00'
np.where(df['end'].dt.time == '23:52:00', (df['end'].dt.normalize() pd.Timedelta('23:59:59')), df['end'])
Out[74]: array(['2021-03-05T23:52:00.000000000', '2021-03-06T12:00:00.000000000',
'2021-04-08T23:00:00.000000000', '2021-04-09T23:52:00.000000000'],
dtype='datetime64[ns]')
CodePudding user response:
If you prefer to compare using datetime
objects, you can do (no need to use np.where
):
mask = df['end'].dt.time == pd.to_datetime('23:52:00').time()
df.loc[mask, 'end'] = df['end'].dt.normalize() pd.Timedelta('23:59:59')
CodePudding user response:
You're comparing wrong types, convert the time to sting:
mask = df['end'].dt.time.astype(str) == '23:52:00'
To replace the values found:
import datetime
df.loc[mask, 'end'] = df[mask]['end'] datetime.timedelta(minutes=7)
replace "minutes=7" with the difference you want.
CodePudding user response:
you have to use date time not string. pandas.to_datetime('23:52:00')