참조: http://pleac.sourceforge.net/pleac_python/datesandtimes.html
from datetime import datetime
d = datetime.now()
d.strftime("%Y-%m-%dT%H:%M:%S-05:00")
'2017-12-08T04:13:48-05:00'
http://knight76.tistory.com/entry/python-pytz%EC%9D%98-%ED%8F%89%EC%96%91%EC%84%9C%EC%9A%B8-%EC%8B%9C%EA%B0%84-%EB%B2%84%EA%B7%B8