An example from the RFC 2445 spec:

>>> from icalendar import Calendar
>>> import os
>>> directory = os.path.dirname(__file__)
>>> cal = Calendar.from_string(
...   open(os.path.join(directory, 'groupscheduled.ics'),'rb').read())
>>> cal
VCALENDAR({'VERSION': vText(u'2.0'), 'PRODID': vText(u'-//RDU Software//NONSGML HandCal//EN')})

>>> timezones = cal.walk('VTIMEZONE')
>>> len(timezones)
1

>>> tz = timezones[0]
>>> tz
VTIMEZONE({'TZID': vText(u'US-Eastern')})

>>> std = tz.walk('STANDARD')[0]
>>> std.decoded('TZOFFSETFROM')
datetime.timedelta(-1, 72000)