["python","datetime","utc","localtime"]
How to convert local time string to UTC?

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 hopefully help me (and others) do that in future. Clarification: For example, if I have 2008-09-17 14:02:00 in my local timezone (+10), I'd like to generate a string with the equivalent UTC time: 2008-09-17 04:02:00. Also, from http://lucumr.pocoo.org/2011/7/15/eppur-si-muove/, note that in general this isn't possible as with DST and other issues there is no unique conversion from local time to UTC time.
Thanks @rofly, the full conversion from string to string is as follows: import time time.strftime("%Y-%m-%d %H:%M:%S", time.gmtime(time.mktime(time.strptime("2008-09-17 14:04:00", "%Y-%m-%d %H:%M:%S")))) My summary of the time/calendar functions: time.strptime string --> tuple (no timezone applied, so matches string) time.mktime local time tuple --> seconds since epoch (always local time) time.gmtime seconds since epoch --> tuple in UTC and calendar.timegm tuple in UTC --> seconds since epoch time.localtime seconds since epoch --> tuple in local timezone