def rollback(self):
self._conn.rollback()<EOL>
Rollback current transaction.

>>> import getpass
>>> s = DB(autocommit=False, dbname='test', user=getpass.getuser(),
... host='localhost', password='')
>>> s.execute('drop table if exists t2')
>>> s.execute('create table t2 (id int, name text)')
>>> s.commit()
>>> s.select('t2')
[]
>>> s.insert('t2', {'id': 1, 'name': 'Tata'})
>>> s.select('t2')
[{'id': 1, 'name': 'Tata'}]
>>> s.rollback()
>>> s.select('t2')
[]