Get UTC offset from time zone name in python

How can I get UTC offset from time zone name in python?

For example: I have Asia/Jerusalem and I want to get +0200

Answer

Because of DST (Daylight Saving Time), the result depends on the time of the year:

import datetime, pytz

datetime.datetime.now(pytz.timezone('Asia/Jerusalem')).strftime('%z')

# returns '+0300' (because 'now' they have DST)


pytz.timezone('Asia/Jerusalem').localize(datetime.datetime(2011,1,1)).strftime('%z')

# returns '+0200' (because in January they didn't have DST)