Example: x days later
import datetime as dt
today = dt.datetime.today()
one_month_later = today + dt.timedelta(days=30)
print(f"today: {today}")
print(f"one_month_later: {one_month_later}")
2020-07-13 20:52:21.473270
one_month_later: 2020-08-12 20:52:21.473270
Example: datetime to string
today = dt.datetime.today() print(today.strftime('%Y%m%d') print(today.strftime('%Y-%m-%d')
20210125
2021-01-25
Example: input date/time from string: strptime (string parsed to time)
%y (lower case) year in 2 digits, like 20
%Y (capital case) year in 4 digits, like 2020
>>> dt.datetime.strptime('2020-01-01', '%Y-%m-%d')
datetime.datetime(2020, 1, 1, 0, 0)
>>> dt.datetime.strptime('20-01-01', '%y-%m-%d')
datetime.datetime(2020, 1, 1, 0, 0)
Example: number of days between two dates
兩個datetime.datetime type變數相減得到datetime.timedelta
>>> today - one_month_later
datetime.timedelta(days=-30)
>>> print(today - one_month_later)
-30 days, 0:00:00
>>> d = today - one_month_later
>>> d.days
-30