You can try the following;
from pytz import timezone
from datetime import datetime
zonename = "Pacific/Wallis"
now = datetime.now(tz=timezone(zonename))
dst_timedelta = now.dst()
### dst_timedelta is offset to the winter time,
### thus timedelta(0) for winter time and timedelta(0, 3600) for DST;
### it returns None if timezone is not set
print "DST" if dst_timedelta else "no DST"
an alternative is to use:
now.timetuple().tm_isdst