What is the standard way to add N seconds to datetime.time in Python?

What is the standard way to add N seconds to datetime.time in Python?

You can use full datetime variables with timedelta, and by providing a dummy date then using time to just get the time value.

For example:

import datetime
a = datetime.datetime(100,1,1,11,34,59)
b = a + datetime.timedelta(0,3) # days, seconds, then other fields.

results in the two values, three seconds apart:


You could also opt for the more readable

b = a + datetime.timedelta(seconds=3)

if youre so inclined.

If youre after a function that can do this, you can look into using addSecs below:

import datetime

def addSecs(tm, secs):
    fulldate = datetime.datetime(100, 1, 1, tm.hour, tm.minute, tm.second)
    fulldate = fulldate + datetime.timedelta(seconds=secs)
    return fulldate.time()

a = datetime.datetime.now().time()
b = addSecs(a, 300)

This outputs:


As others here have stated, you can just use full datetime objects throughout:

from datetime import datetime, date, time, timedelta
sometime = time(8,00) # 8am
later = (datetime.combine(date.today(), sometime) + timedelta(seconds=3)).time()

However, I think its worth explaining why full datetime objects are required. Consider what would happen if I added 2 hours to 11pm. Whats the correct behavior? An exception, because you cant have a time larger than 11:59pm? Should it wrap back around?

Different programmers will expect different things, so whichever result they picked would surprise a lot of people. Worse yet, programmers would write code that worked just fine when they tested it initially, and then have it break later by doing something unexpected. This is very bad, which is why youre not allowed to add timedelta objects to time objects.

What is the standard way to add N seconds to datetime.time in Python?

One little thing, might add clarity to override the default value for seconds

>>> b = a + datetime.timedelta(seconds=3000)
>>> b
datetime.datetime(1, 1, 1, 12, 24, 59)

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