#!/usr/bin/env python

import sys
import psycopg2


for level in (0, 1, 2):
    connection = psycopg2.connect(sys.argv[1])
    connection.set_isolation_level(1)

    print 'In isolation level: %d' % (level,)

    c = connection.cursor()
    c.execute('SHOW TIME ZONE')
    print 'Original time zone: %s' % (c.fetchone()[0],)

    c = connection.cursor()
    c.execute('SET TIME ZONE \'EST\'')
    c.execute('SHOW TIME ZONE')
    print 'Set timezone to: %s' % (c.fetchone()[0],)
    connection.commit()
    
    c = connection.cursor()
    c.execute('SHOW TIME ZONE')
    print 'Next cursor got time zone: %s' % (c.fetchone()[0],)
    
    connection.close()