С округлением
- Добавьте
timedelta
разницу между 1e6 и a.microsecond
from datetime import timedelta, datetime
a = datetime.fromisoformat('2020-01-01 19:30:33.996628')
a = a + timedelta(microseconds=(1e6 - a.microsecond))
print(a)
>>> datetime.datetime(2020, 1, 1, 19, 30, 34)
print(a.strftime('%Y-%m-%d %H:%M:%S'))
>>> 2020-01-01 19:30:34
С .replace(microsecond=0)
from datetime import datetime
a = datetime.fromisoformat('2020-01-01 19:30:33.996628')
print(a)
>>> datetime.datetime(2020, 1, 1, 19, 30, 33, 996628)
a = a.replace(microsecond=0)
print(a)
>>> datetime.datetime(2020, 1, 1, 19, 30, 33)