from datetime import datetime,timezone,timedelta
import re

def to_timestamp(dt_str,tz_str):
    dt=datetime.strptime(dt_str,'%Y-%m-%d %H:%M:%S')
    hs=int(re.match(r'^UTC([+|-]\d{1,2}):\d{2}$',tz_str).group(1))
    dt_with_zone=dt.replace(tzinfo=timezone(timedelta(hours=hs)))
    return dt_with_zone.timestamp()

if __name__=='__main__':
    t1 = to_timestamp('2015-6-1 08:10:30', 'UTC+7:00')
    assert t1 == 1433121030.0, t1

    t2 = to_timestamp('2015-5-31 16:10:30', 'UTC-09:00')
    assert t2 == 1433121030.0, t2

    print('ok')