[python] datetime <-> timestamp <-> string

ubuntu 14.04

>>> import datetime

>>> import time

##### string -> datetime object #####

>>> string_date = '2016-08-31 00:00:00'

>>> dobj = datetime.datetime.strptime(string_date,'%Y-%m-%d %H:%M:%S')

>>> dobj

datetime.datetime(2016, 8, 31, 0, 0)

##### datetime object -> timestamp #####

>>> timestamp = time.mktime(dobj.timetuple())

>>> timestamp

1472569200.0

##### timestamp -> datetime object #####

>>> dobj2 = datetime.datetime.fromtimestamp(timestamp)

>>> dobj2

datetime.datetime(2016, 8, 31, 0, 0)