Drop Mili Sencond из DateTime Index
>>> d = datetime.datetime.today().replace(microsecond=0)
>>> d
datetime.datetime(2015, 7, 18, 9, 50, 20)
Clumsy Cowfish
>>> d = datetime.datetime.today().replace(microsecond=0)
>>> d
datetime.datetime(2015, 7, 18, 9, 50, 20)