How to convert local time string to UTC?

Question

How do I convert a datetime string in local time to a string in UTC time?

I\'m sure I\'ve done this before, but can\'t find it and SO will hopefull

Answer 1

I'm having good luck with dateutil (which is widely recommended on SO for other related questions):

from datetime import *
from dateutil import *
from dateutil.tz import *

# METHOD 1: Hardcode zones:
utc_zone = tz.gettz('UTC')
local_zone = tz.gettz('America/Chicago')
# METHOD 2: Auto-detect zones:
utc_zone = tz.tzutc()
local_zone = tz.tzlocal()

# Convert time string to datetime
local_time = datetime.strptime("2008-09-17 14:02:00", '%Y-%m-%d %H:%M:%S')

# Tell the datetime object that it's in local time zone since 
# datetime objects are 'naive' by default
local_time = local_time.replace(tzinfo=local_zone)
# Convert time to UTC
utc_time = local_time.astimezone(utc_zone)
# Generate UTC time string
utc_string = utc_time.strftime('%Y-%m-%d %H:%M:%S')

(Code was derived from this answer to Convert UTC datetime string to local datetime)