simple way to drop milliseconds from python datetime.datetime object

My colleague needs me to drop the milliseconds from my python timestamp objects in order to comply with the old POSIX (IEEE Std 1003.1-1988) standard. The tortured route that accomplishes this task for me is as follows:

datetime.datetime.strptime(datetime.datetime.today().strftime("%Y-%m-%d %H:%M:%S"),"%Y-%m-%d %H:%M:%S")

Is there a simpler way to end up with a datetime.datetime object for mongoDB than this?

You can use datetime.replace() method -

>>> d = datetime.datetime.today().replace(microsecond=0)
>>> d
datetime.datetime(2015, 7, 18, 9, 50, 20)